diff options
Diffstat (limited to 'freebsd/contrib/libpcap/pcap-bpf.c')
| -rw-r--r-- | freebsd/contrib/libpcap/pcap-bpf.c | 2719 |
1 files changed, 2719 insertions, 0 deletions
diff --git a/freebsd/contrib/libpcap/pcap-bpf.c b/freebsd/contrib/libpcap/pcap-bpf.c new file mode 100644 index 00000000..0a942601 --- /dev/null +++ b/freebsd/contrib/libpcap/pcap-bpf.c @@ -0,0 +1,2719 @@ +#include <machine/rtems-bsd-user-space.h> + +/* + * Copyright (c) 1993, 1994, 1995, 1996, 1998 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that: (1) source code distributions + * retain the above copyright notice and this paragraph in its entirety, (2) + * distributions including binary code include the above copyright notice and + * this paragraph in its entirety in the documentation or other materials + * provided with the distribution, and (3) all advertising materials mentioning + * features or use of this software display the following acknowledgement: + * ``This product includes software developed by the University of California, + * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of + * the University nor the names of its contributors may be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * $FreeBSD$ + */ +#ifndef lint +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.116 2008-09-16 18:42:29 guy Exp $ (LBL)"; +#endif + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <rtems/bsd/sys/param.h> /* optionally get BSD define */ +#ifdef HAVE_ZEROCOPY_BPF +#include <sys/mman.h> +#endif +#include <sys/socket.h> +#include <time.h> +/* + * <net/bpf.h> defines ioctls, but doesn't include <sys/ioccom.h>. + * + * We include <sys/ioctl.h> as it might be necessary to declare ioctl(); + * at least on *BSD and Mac OS X, it also defines various SIOC ioctls - + * we could include <sys/sockio.h>, but if we're already including + * <sys/ioctl.h>, which includes <sys/sockio.h> on those platforms, + * there's not much point in doing so. + * + * If we have <sys/ioccom.h>, we include it as well, to handle systems + * such as Solaris which don't arrange to include <sys/ioccom.h> if you + * include <sys/ioctl.h> + */ +#include <sys/ioctl.h> +#ifdef HAVE_SYS_IOCCOM_H +#include <sys/ioccom.h> +#endif +#include <sys/utsname.h> + +#ifdef HAVE_ZEROCOPY_BPF +#include <machine/atomic.h> +#endif + +#include <net/if.h> + +#ifdef _AIX + +/* + * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the + * native OS version, as we need "struct bpf_config" from it. + */ +#define PCAP_DONT_INCLUDE_PCAP_BPF_H + +#include <rtems/bsd/sys/types.h> + +/* + * Prevent bpf.h from redefining the DLT_ values to their + * IFT_ values, as we're going to return the standard libpcap + * values, not IBM's non-standard IFT_ values. + */ +#undef _AIX +#include <net/bpf.h> +#define _AIX + +#include <net/if_types.h> /* for IFT_ values */ +#include <sys/sysconfig.h> +#include <sys/device.h> +#include <sys/cfgodm.h> +#include <cf.h> + +#ifdef __64BIT__ +#define domakedev makedev64 +#define getmajor major64 +#define bpf_hdr bpf_hdr32 +#else /* __64BIT__ */ +#define domakedev makedev +#define getmajor major +#endif /* __64BIT__ */ + +#define BPF_NAME "bpf" +#define BPF_MINORS 4 +#define DRIVER_PATH "/usr/lib/drivers" +#define BPF_NODE "/dev/bpf" +static int bpfloadedflag = 0; +static int odmlockid = 0; + +static int bpf_load(char *errbuf); + +#else /* _AIX */ + +#include <net/bpf.h> + +#endif /* _AIX */ + +#include <ctype.h> +#include <fcntl.h> +#include <errno.h> +#include <netdb.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#ifdef HAVE_NET_IF_MEDIA_H +# include <net/if_media.h> +#endif + +#include "pcap-int.h" + +#ifdef HAVE_OS_PROTO_H +#include "os-proto.h" +#endif + +#ifdef BIOCGDLTLIST +# if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) +#define HAVE_BSD_IEEE80211 +# endif + +# if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) +static int find_802_11(struct bpf_dltlist *); + +# ifdef HAVE_BSD_IEEE80211 +static int monitor_mode(pcap_t *, int); +# endif + +# if defined(__APPLE__) +static void remove_en(pcap_t *); +static void remove_802_11(pcap_t *); +# endif + +# endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ + +#endif /* BIOCGDLTLIST */ + +#if defined(sun) && defined(LIFNAMSIZ) && defined(lifr_zoneid) +#include <zone.h> +#endif + +/* + * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably + * don't get DLT_DOCSIS defined. + */ +#ifndef DLT_DOCSIS +#define DLT_DOCSIS 143 +#endif + +/* + * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s + * defined, even though some of them are used by various Airport drivers. + */ +#ifndef DLT_PRISM_HEADER +#define DLT_PRISM_HEADER 119 +#endif +#ifndef DLT_AIRONET_HEADER +#define DLT_AIRONET_HEADER 120 +#endif +#ifndef DLT_IEEE802_11_RADIO +#define DLT_IEEE802_11_RADIO 127 +#endif +#ifndef DLT_IEEE802_11_RADIO_AVS +#define DLT_IEEE802_11_RADIO_AVS 163 +#endif + +static int pcap_can_set_rfmon_bpf(pcap_t *p); +static int pcap_activate_bpf(pcap_t *p); +static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); +static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); +static int pcap_set_datalink_bpf(pcap_t *p, int dlt); + +/* + * For zerocopy bpf, the setnonblock/getnonblock routines need to modify + * p->md.timeout so we don't call select(2) if the pcap handle is in non- + * blocking mode. We preserve the timeout supplied by pcap_open functions + * to make sure it does not get clobbered if the pcap handle moves between + * blocking and non-blocking mode. + */ +static int +pcap_getnonblock_bpf(pcap_t *p, char *errbuf) +{ +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.zerocopy) { + /* + * Use a negative value for the timeout to represent that the + * pcap handle is in non-blocking mode. + */ + return (p->md.timeout < 0); + } +#endif + return (pcap_getnonblock_fd(p, errbuf)); +} + +static int +pcap_setnonblock_bpf(pcap_t *p, int nonblock, char *errbuf) +{ +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.zerocopy) { + /* + * Map each value to their corresponding negation to + * preserve the timeout value provided with pcap_set_timeout. + * (from pcap-linux.c). + */ + if (nonblock) { + if (p->md.timeout >= 0) { + /* + * Indicate that we're switching to + * non-blocking mode. + */ + p->md.timeout = ~p->md.timeout; + } + } else { + if (p->md.timeout < 0) { + p->md.timeout = ~p->md.timeout; + } + } + return (0); + } +#endif + return (pcap_setnonblock_fd(p, nonblock, errbuf)); +} + +#ifdef HAVE_ZEROCOPY_BPF +/* + * Zero-copy BPF buffer routines to check for and acknowledge BPF data in + * shared memory buffers. + * + * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, + * and set up p->buffer and cc to reflect one if available. Notice that if + * there was no prior buffer, we select zbuf1 as this will be the first + * buffer filled for a fresh BPF session. + */ +static int +pcap_next_zbuf_shm(pcap_t *p, int *cc) +{ + struct bpf_zbuf_header *bzh; + + if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) { + bzh = (struct bpf_zbuf_header *)p->md.zbuf1; + if (bzh->bzh_user_gen != + atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + p->md.bzh = bzh; + p->md.zbuffer = (u_char *)p->md.zbuf1; + p->buffer = p->md.zbuffer + sizeof(*bzh); + *cc = bzh->bzh_kernel_len; + return (1); + } + } else if (p->md.zbuffer == p->md.zbuf1) { + bzh = (struct bpf_zbuf_header *)p->md.zbuf2; + if (bzh->bzh_user_gen != + atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + p->md.bzh = bzh; + p->md.zbuffer = (u_char *)p->md.zbuf2; + p->buffer = p->md.zbuffer + sizeof(*bzh); + *cc = bzh->bzh_kernel_len; + return (1); + } + } + *cc = 0; + return (0); +} + +/* + * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using + * select() for data or a timeout, and possibly force rotation of the buffer + * in the event we time out or are in immediate mode. Invoke the shared + * memory check before doing system calls in order to avoid doing avoidable + * work. + */ +static int +pcap_next_zbuf(pcap_t *p, int *cc) +{ + struct bpf_zbuf bz; + struct timeval tv; + struct timespec cur; + fd_set r_set; + int data, r; + int expire, tmout; + +#define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) + /* + * Start out by seeing whether anything is waiting by checking the + * next shared memory buffer for data. + */ + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + /* + * If a previous sleep was interrupted due to signal delivery, make + * sure that the timeout gets adjusted accordingly. This requires + * that we analyze when the timeout should be been expired, and + * subtract the current time from that. If after this operation, + * our timeout is less then or equal to zero, handle it like a + * regular timeout. + */ + tmout = p->md.timeout; + if (tmout) + (void) clock_gettime(CLOCK_MONOTONIC, &cur); + if (p->md.interrupted && p->md.timeout) { + expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout; + tmout = expire - TSTOMILLI(&cur); +#undef TSTOMILLI + if (tmout <= 0) { + p->md.interrupted = 0; + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCROTZBUF: %s", strerror(errno)); + return (PCAP_ERROR); + } + return (pcap_next_zbuf_shm(p, cc)); + } + } + /* + * No data in the buffer, so must use select() to wait for data or + * the next timeout. Note that we only call select if the handle + * is in blocking mode. + */ + if (p->md.timeout >= 0) { + FD_ZERO(&r_set); + FD_SET(p->fd, &r_set); + if (tmout != 0) { + tv.tv_sec = tmout / 1000; + tv.tv_usec = (tmout * 1000) % 1000000; + } + r = select(p->fd + 1, &r_set, NULL, NULL, + p->md.timeout != 0 ? &tv : NULL); + if (r < 0 && errno == EINTR) { + if (!p->md.interrupted && p->md.timeout) { + p->md.interrupted = 1; + p->md.firstsel = cur; + } + return (0); + } else if (r < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "select: %s", strerror(errno)); + return (PCAP_ERROR); + } + } + p->md.interrupted = 0; + /* + * Check again for data, which may exist now that we've either been + * woken up as a result of data or timed out. Try the "there's data" + * case first since it doesn't require a system call. + */ + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + /* + * Try forcing a buffer rotation to dislodge timed out or immediate + * data. + */ + if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCROTZBUF: %s", strerror(errno)); + return (PCAP_ERROR); + } + return (pcap_next_zbuf_shm(p, cc)); +} + +/* + * Notify kernel that we are done with the buffer. We don't reset zbuffer so + * that we know which buffer to use next time around. + */ +static int +pcap_ack_zbuf(pcap_t *p) +{ + + atomic_store_rel_int(&p->md.bzh->bzh_user_gen, + p->md.bzh->bzh_kernel_gen); + p->md.bzh = NULL; + p->buffer = NULL; + return (0); +} +#endif /* HAVE_ZEROCOPY_BPF */ + +pcap_t * +pcap_create_interface(const char *device, char *ebuf) +{ + pcap_t *p; + + p = pcap_create_common(device, ebuf); + if (p == NULL) + return (NULL); + + p->activate_op = pcap_activate_bpf; + p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; + return (p); +} + +/* + * On success, returns a file descriptor for a BPF device. + * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf. + */ +static int +bpf_open(pcap_t *p) +{ + int fd; +#ifdef HAVE_CLONING_BPF + static const char device[] = "/dev/bpf"; +#else + int n = 0; + char device[sizeof "/dev/bpf0000000000"]; +#endif + +#ifdef _AIX + /* + * Load the bpf driver, if it isn't already loaded, + * and create the BPF device entries, if they don't + * already exist. + */ + if (bpf_load(p->errbuf) == PCAP_ERROR) + return (PCAP_ERROR); +#endif + +#ifdef HAVE_CLONING_BPF + if ((fd = open(device, O_RDWR)) == -1 && + (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) { + if (errno == EACCES) + fd = PCAP_ERROR_PERM_DENIED; + else + fd = PCAP_ERROR; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(cannot open device) %s: %s", device, pcap_strerror(errno)); + } +#else + /* + * Go through all the minors and find one that isn't in use. + */ + do { + (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); + /* + * Initially try a read/write open (to allow the inject + * method to work). If that fails due to permission + * issues, fall back to read-only. This allows a + * non-root user to be granted specific access to pcap + * capabilities via file permissions. + * + * XXX - we should have an API that has a flag that + * controls whether to open read-only or read-write, + * so that denial of permission to send (or inability + * to send, if sending packets isn't supported on + * the device in question) can be indicated at open + * time. + */ + fd = open(device, O_RDWR); + if (fd == -1 && errno == EACCES) + fd = open(device, O_RDONLY); + } while (fd < 0 && errno == EBUSY); + + /* + * XXX better message for all minors used + */ + if (fd < 0) { + switch (errno) { + + case ENOENT: + fd = PCAP_ERROR; + if (n == 1) { + /* + * /dev/bpf0 doesn't exist, which + * means we probably have no BPF + * devices. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(there are no BPF devices)"); + } else { + /* + * We got EBUSY on at least one + * BPF device, so we have BPF + * devices, but all the ones + * that exist are busy. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(all BPF devices are busy)"); + } + break; + + case EACCES: + /* + * Got EACCES on the last device we tried, + * and EBUSY on all devices before that, + * if any. + */ + fd = PCAP_ERROR_PERM_DENIED; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(cannot open BPF device) %s: %s", device, + pcap_strerror(errno)); + break; + + default: + /* + * Some other problem. + */ + fd = PCAP_ERROR; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(cannot open BPF device) %s: %s", device, + pcap_strerror(errno)); + break; + } + } +#endif + + return (fd); +} + +#ifdef BIOCGDLTLIST +static int +get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) +{ + memset(bdlp, 0, sizeof(*bdlp)); + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { + u_int i; + int is_ethernet; + + bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); + if (bdlp->bfl_list == NULL) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + "BIOCGDLTLIST: %s", pcap_strerror(errno)); + free(bdlp->bfl_list); + return (PCAP_ERROR); + } + + /* + * OK, for real Ethernet devices, add DLT_DOCSIS to the + * list, so that an application can let you choose it, + * in case you're capturing DOCSIS traffic that a Cisco + * Cable Modem Termination System is putting out onto + * an Ethernet (it doesn't put an Ethernet header onto + * the wire, it puts raw DOCSIS frames out on the wire + * inside the low-level Ethernet framing). + * + * A "real Ethernet device" is defined here as a device + * that has a link-layer type of DLT_EN10MB and that has + * no alternate link-layer types; that's done to exclude + * 802.11 interfaces (which might or might not be the + * right thing to do, but I suspect it is - Ethernet <-> + * 802.11 bridges would probably badly mishandle frames + * that don't have Ethernet headers). + * + * On Solaris with BPF, Ethernet devices also offer + * DLT_IPNET, so we, if DLT_IPNET is defined, we don't + * treat it as an indication that the device isn't an + * Ethernet. + */ + if (v == DLT_EN10MB) { + is_ethernet = 1; + for (i = 0; i < bdlp->bfl_len; i++) { + if (bdlp->bfl_list[i] != DLT_EN10MB +#ifdef DLT_IPNET + && bdlp->bfl_list[i] != DLT_IPNET +#endif + ) { + is_ethernet = 0; + break; + } + } + if (is_ethernet) { + /* + * We reserved one more slot at the end of + * the list. + */ + bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; + bdlp->bfl_len++; + } + } + } else { + /* + * EINVAL just means "we don't support this ioctl on + * this device"; don't treat it as an error. + */ + if (errno != EINVAL) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + "BIOCGDLTLIST: %s", pcap_strerror(errno)); + return (PCAP_ERROR); + } + } + return (0); +} +#endif + +static int +pcap_can_set_rfmon_bpf(pcap_t *p) +{ +#if defined(__APPLE__) + struct utsname osinfo; + struct ifreq ifr; + int fd; +#ifdef BIOCGDLTLIST + struct bpf_dltlist bdl; +#endif + + /* + * The joys of monitor mode on OS X. + * + * Prior to 10.4, it's not supported at all. + * + * In 10.4, if adapter enN supports monitor mode, there's a + * wltN adapter corresponding to it; you open it, instead of + * enN, to get monitor mode. You get whatever link-layer + * headers it supplies. + * + * In 10.5, and, we assume, later releases, if adapter enN + * supports monitor mode, it offers, among its selectable + * DLT_ values, values that let you get the 802.11 header; + * selecting one of those values puts the adapter into monitor + * mode (i.e., you can't get 802.11 headers except in monitor + * mode, and you can't get Ethernet headers in monitor mode). + */ + if (uname(&osinfo) == -1) { + /* + * Can't get the OS version; just say "no". + */ + return (0); + } + /* + * We assume osinfo.sysname is "Darwin", because + * __APPLE__ is defined. We just check the version. + */ + if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { + /* + * 10.3 (Darwin 7.x) or earlier. + * Monitor mode not supported. + */ + return (0); + } + if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { + /* + * 10.4 (Darwin 8.x). s/en/wlt/, and check + * whether the device exists. + */ + if (strncmp(p->opt.source, "en", 2) != 0) { + /* + * Not an enN device; no monitor mode. + */ + return (0); + } + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd == -1) { + (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "socket: %s", pcap_strerror(errno)); + return (PCAP_ERROR); + } + strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name)); + strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { + /* + * No such device? + */ + close(fd); + return (0); + } + close(fd); + return (1); + } + +#ifdef BIOCGDLTLIST + /* + * Everything else is 10.5 or later; for those, + * we just open the enN device, and check whether + * we have any 802.11 devices. + * + * First, open a BPF device. + */ + fd = bpf_open(p); + if (fd < 0) + return (fd); /* fd is the appropriate error code */ + + /* + * Now bind to the device. + */ + (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { + switch (errno) { + + case ENXIO: + /* + * There's no such device. + */ + close(fd); + return (PCAP_ERROR_NO_SUCH_DEVICE); + + case ENETDOWN: + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + close(fd); + return (PCAP_ERROR_IFACE_NOT_UP); + + default: + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + close(fd); + return (PCAP_ERROR); + } + } + + /* + * We know the default link type -- now determine all the DLTs + * this interface supports. If this fails with EINVAL, it's + * not fatal; we just don't get to use the feature later. + * (We don't care about DLT_DOCSIS, so we pass DLT_NULL + * as the default DLT for this adapter.) + */ + if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { + close(fd); + return (PCAP_ERROR); + } + if (find_802_11(&bdl) != -1) { + /* + * We have an 802.11 DLT, so we can set monitor mode. + */ + free(bdl.bfl_list); + close(fd); + return (1); + } + free(bdl.bfl_list); +#endif /* BIOCGDLTLIST */ + return (0); +#elif defined(HAVE_BSD_IEEE80211) + int ret; + + ret = monitor_mode(p, 0); + if (ret == PCAP_ERROR_RFMON_NOTSUP) + return (0); /* not an error, just a "can't do" */ + if (ret == 0) + return (1); /* success */ + return (ret); +#else + return (0); +#endif +} + +static int +pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) +{ + struct bpf_stat s; + + /* + * "ps_recv" counts packets handed to the filter, not packets + * that passed the filter. This includes packets later dropped + * because we ran out of buffer space. + * + * "ps_drop" counts packets dropped inside the BPF device + * because we ran out of buffer space. It doesn't count + * packets dropped by the interface driver. It counts + * only packets that passed the filter. + * + * Both statistics include packets not yet read from the kernel + * by libpcap, and thus not yet seen by the application. + */ + if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + ps->ps_recv = s.bs_recv; + ps->ps_drop = s.bs_drop; + ps->ps_ifdrop = 0; + return (0); +} + +static int +pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) +{ + int cc; + int n = 0; + register u_char *bp, *ep; + u_char *datap; +#ifdef PCAP_FDDIPAD + register int pad; +#endif +#ifdef HAVE_ZEROCOPY_BPF + int i; +#endif + + again: + /* + * Has "pcap_breakloop()" been called? + */ + if (p->break_loop) { + /* + * Yes - clear the flag that indicates that it + * has, and return PCAP_ERROR_BREAK to indicate + * that we were told to break out of the loop. + */ + p->break_loop = 0; + return (PCAP_ERROR_BREAK); + } + cc = p->cc; + if (p->cc == 0) { + /* + * When reading without zero-copy from a file descriptor, we + * use a single buffer and return a length of data in the + * buffer. With zero-copy, we update the p->buffer pointer + * to point at whatever underlying buffer contains the next + * data and update cc to reflect the data found in the + * buffer. + */ +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.zerocopy) { + if (p->buffer != NULL) + pcap_ack_zbuf(p); + i = pcap_next_zbuf(p, &cc); + if (i == 0) + goto again; + if (i < 0) + return (PCAP_ERROR); + } else +#endif + { + cc = read(p->fd, (char *)p->buffer, p->bufsize); + } + if (cc < 0) { + /* Don't choke when we get ptraced */ + switch (errno) { + + case EINTR: + goto again; + +#ifdef _AIX + case EFAULT: + /* + * Sigh. More AIX wonderfulness. + * + * For some unknown reason the uiomove() + * operation in the bpf kernel extension + * used to copy the buffer into user + * space sometimes returns EFAULT. I have + * no idea why this is the case given that + * a kernel debugger shows the user buffer + * is correct. This problem appears to + * be mostly mitigated by the memset of + * the buffer before it is first used. + * Very strange.... Shaun Clowes + * + * In any case this means that we shouldn't + * treat EFAULT as a fatal error; as we + * don't have an API for returning + * a "some packets were dropped since + * the last packet you saw" indication, + * we just ignore EFAULT and keep reading. + */ + goto again; +#endif + + case EWOULDBLOCK: + return (0); + + case ENXIO: + /* + * The device on which we're capturing + * went away. + * + * XXX - we should really return + * PCAP_ERROR_IFACE_NOT_UP, but + * pcap_dispatch() etc. aren't + * defined to retur that. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "The interface went down"); + return (PCAP_ERROR); + +#if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4) + /* + * Due to a SunOS bug, after 2^31 bytes, the kernel + * file offset overflows and read fails with EINVAL. + * The lseek() to 0 will fix things. + */ + case EINVAL: + if (lseek(p->fd, 0L, SEEK_CUR) + + p->bufsize < 0) { + (void)lseek(p->fd, 0L, SEEK_SET); + goto again; + } + /* fall through */ +#endif + } + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + bp = p->buffer; + } else + bp = p->bp; + + /* + * Loop through each packet. + */ +#define bhp ((struct bpf_hdr *)bp) + ep = bp + cc; +#ifdef PCAP_FDDIPAD + pad = p->fddipad; +#endif + while (bp < ep) { + register int caplen, hdrlen; + + /* + * Has "pcap_breakloop()" been called? + * If so, return immediately - if we haven't read any + * packets, clear the flag and return PCAP_ERROR_BREAK + * to indicate that we were told to break out of the loop, + * otherwise leave the flag set, so that the *next* call + * will break out of the loop without having read any + * packets, and return the number of packets we've + * processed so far. + */ + if (p->break_loop) { + p->bp = bp; + p->cc = ep - bp; + /* + * ep is set based on the return value of read(), + * but read() from a BPF device doesn't necessarily + * return a value that's a multiple of the alignment + * value for BPF_WORDALIGN(). However, whenever we + * increment bp, we round up the increment value by + * a value rounded up by BPF_WORDALIGN(), so we + * could increment bp past ep after processing the + * last packet in the buffer. + * + * We treat ep < bp as an indication that this + * happened, and just set p->cc to 0. + */ + if (p->cc < 0) + p->cc = 0; + if (n == 0) { + p->break_loop = 0; + return (PCAP_ERROR_BREAK); + } else + return (n); + } + + caplen = bhp->bh_caplen; + hdrlen = bhp->bh_hdrlen; + datap = bp + hdrlen; + /* + * Short-circuit evaluation: if using BPF filter + * in kernel, no need to do it now - we already know + * the packet passed the filter. + * +#ifdef PCAP_FDDIPAD + * Note: the filter code was generated assuming + * that p->fddipad was the amount of padding + * before the header, as that's what's required + * in the kernel, so we run the filter before + * skipping that padding. +#endif + */ + if (p->md.use_bpf || + bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { + struct pcap_pkthdr pkthdr; + + pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; +#ifdef _AIX + /* + * AIX's BPF returns seconds/nanoseconds time + * stamps, not seconds/microseconds time stamps. + */ + pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000; +#else + pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec; +#endif +#ifdef PCAP_FDDIPAD + if (caplen > pad) + pkthdr.caplen = caplen - pad; + else + pkthdr.caplen = 0; + if (bhp->bh_datalen > pad) + pkthdr.len = bhp->bh_datalen - pad; + else + pkthdr.len = 0; + datap += pad; +#else + pkthdr.caplen = caplen; + pkthdr.len = bhp->bh_datalen; +#endif + (*callback)(user, &pkthdr, datap); + bp += BPF_WORDALIGN(caplen + hdrlen); + if (++n >= cnt && cnt > 0) { + p->bp = bp; + p->cc = ep - bp; + /* + * See comment above about p->cc < 0. + */ + if (p->cc < 0) + p->cc = 0; + return (n); + } + } else { + /* + * Skip this packet. + */ + bp += BPF_WORDALIGN(caplen + hdrlen); + } + } +#undef bhp + p->cc = 0; + return (n); +} + +static int +pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) +{ + int ret; + + ret = write(p->fd, buf, size); +#ifdef __APPLE__ + if (ret == -1 && errno == EAFNOSUPPORT) { + /* + * In Mac OS X, there's a bug wherein setting the + * BIOCSHDRCMPLT flag causes writes to fail; see, + * for example: + * + * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch + * + * So, if, on OS X, we get EAFNOSUPPORT from the write, we + * assume it's due to that bug, and turn off that flag + * and try again. If we succeed, it either means that + * somebody applied the fix from that URL, or other patches + * for that bug from + * + * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/ + * + * and are running a Darwin kernel with those fixes, or + * that Apple fixed the problem in some OS X release. + */ + u_int spoof_eth_src = 0; + + if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { + (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "send: can't turn off BIOCSHDRCMPLT: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + /* + * Now try the write again. + */ + ret = write(p->fd, buf, size); + } +#endif /* __APPLE__ */ + if (ret == -1) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + return (ret); +} + +#ifdef _AIX +static int +bpf_odminit(char *errbuf) +{ + char *errstr; + + if (odm_initialize() == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_initialize failed: %s", + errstr); + return (PCAP_ERROR); + } + + if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", + errstr); + (void)odm_terminate(); + return (PCAP_ERROR); + } + + return (0); +} + +static int +bpf_odmcleanup(char *errbuf) +{ + char *errstr; + + if (odm_unlock(odmlockid) == -1) { + if (errbuf != NULL) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_unlock failed: %s", + errstr); + } + return (PCAP_ERROR); + } + + if (odm_terminate() == -1) { + if (errbuf != NULL) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_terminate failed: %s", + errstr); + } + return (PCAP_ERROR); + } + + return (0); +} + +static int +bpf_load(char *errbuf) +{ + long major; + int *minors; + int numminors, i, rc; + char buf[1024]; + struct stat sbuf; + struct bpf_config cfg_bpf; + struct cfg_load cfg_ld; + struct cfg_kmod cfg_km; + + /* + * This is very very close to what happens in the real implementation + * but I've fixed some (unlikely) bug situations. + */ + if (bpfloadedflag) + return (0); + + if (bpf_odminit(errbuf) == PCAP_ERROR) + return (PCAP_ERROR); + + major = genmajor(BPF_NAME); + if (major == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: genmajor failed: %s", pcap_strerror(errno)); + (void)bpf_odmcleanup(NULL); + return (PCAP_ERROR); + } + + minors = getminor(major, &numminors, BPF_NAME); + if (!minors) { + minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); + if (!minors) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: genminor failed: %s", + pcap_strerror(errno)); + (void)bpf_odmcleanup(NULL); + return (PCAP_ERROR); + } + } + + if (bpf_odmcleanup(errbuf) == PCAP_ERROR) + return (PCAP_ERROR); + + rc = stat(BPF_NODE "0", &sbuf); + if (rc == -1 && errno != ENOENT) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: can't stat %s: %s", + BPF_NODE "0", pcap_strerror(errno)); + return (PCAP_ERROR); + } + + if (rc == -1 || getmajor(sbuf.st_rdev) != major) { + for (i = 0; i < BPF_MINORS; i++) { + sprintf(buf, "%s%d", BPF_NODE, i); + unlink(buf); + if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: can't mknod %s: %s", + buf, pcap_strerror(errno)); + return (PCAP_ERROR); + } + } + } + + /* Check if the driver is loaded */ + memset(&cfg_ld, 0x0, sizeof(cfg_ld)); + cfg_ld.path = buf; + sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME); + if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || + (cfg_ld.kmid == 0)) { + /* Driver isn't loaded, load it now */ + if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: could not load driver: %s", + strerror(errno)); + return (PCAP_ERROR); + } + } + + /* Configure the driver */ + cfg_km.cmd = CFG_INIT; + cfg_km.kmid = cfg_ld.kmid; + cfg_km.mdilen = sizeof(cfg_bpf); + cfg_km.mdiptr = (void *)&cfg_bpf; + for (i = 0; i < BPF_MINORS; i++) { + cfg_bpf.devno = domakedev(major, i); + if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: could not configure driver: %s", + strerror(errno)); + return (PCAP_ERROR); + } + } + + bpfloadedflag = 1; + + return (0); +} +#endif + +/* + * Turn off rfmon mode if necessary. + */ +static void +pcap_cleanup_bpf(pcap_t *p) +{ +#ifdef HAVE_BSD_IEEE80211 + int sock; + struct ifmediareq req; + struct ifreq ifr; +#endif + + if (p->md.must_do_on_close != 0) { + /* + * There's something we have to do when closing this + * pcap_t. + */ +#ifdef HAVE_BSD_IEEE80211 + if (p->md.must_do_on_close & MUST_CLEAR_RFMON) { + /* + * We put the interface into rfmon mode; + * take it out of rfmon mode. + * + * XXX - if somebody else wants it in rfmon + * mode, this code cannot know that, so it'll take + * it out of rfmon mode. + */ + sock = socket(AF_INET, SOCK_DGRAM, 0); + if (sock == -1) { + fprintf(stderr, + "Can't restore interface flags (socket() failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } else { + memset(&req, 0, sizeof(req)); + strncpy(req.ifm_name, p->md.device, + sizeof(req.ifm_name)); + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { + fprintf(stderr, + "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } else { + if (req.ifm_current & IFM_IEEE80211_MONITOR) { + /* + * Rfmon mode is currently on; + * turn it off. + */ + memset(&ifr, 0, sizeof(ifr)); + (void)strncpy(ifr.ifr_name, + p->md.device, + sizeof(ifr.ifr_name)); + ifr.ifr_media = + req.ifm_current & ~IFM_IEEE80211_MONITOR; + if (ioctl(sock, SIOCSIFMEDIA, + &ifr) == -1) { + fprintf(stderr, + "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } + } + } + close(sock); + } + } +#endif /* HAVE_BSD_IEEE80211 */ + + /* + * Take this pcap out of the list of pcaps for which we + * have to take the interface out of some mode. + */ + pcap_remove_from_pcaps_to_close(p); + p->md.must_do_on_close = 0; + } + +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.zerocopy) { + /* + * Delete the mappings. Note that p->buffer gets + * initialized to one of the mmapped regions in + * this case, so do not try and free it directly; + * null it out so that pcap_cleanup_live_common() + * doesn't try to free it. + */ + if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL) + (void) munmap(p->md.zbuf1, p->md.zbufsize); + if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL) + (void) munmap(p->md.zbuf2, p->md.zbufsize); + p->buffer = NULL; + p->buffer = NULL; + } +#endif + if (p->md.device != NULL) { + free(p->md.device); + p->md.device = NULL; + } + pcap_cleanup_live_common(p); +} + +static int +check_setif_failure(pcap_t *p, int error) +{ +#ifdef __APPLE__ + int fd; + struct ifreq ifr; + int err; +#endif + + if (error == ENXIO) { + /* + * No such device exists. + */ +#ifdef __APPLE__ + if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) { + /* + * Monitor mode was requested, and we're trying + * to open a "wltN" device. Assume that this + * is 10.4 and that we were asked to open an + * "enN" device; if that device exists, return + * "monitor mode not supported on the device". + */ + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd != -1) { + strlcpy(ifr.ifr_name, "en", + sizeof(ifr.ifr_name)); + strlcat(ifr.ifr_name, p->opt.source + 3, + sizeof(ifr.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { + /* + * We assume this failed because + * the underlying device doesn't + * exist. + */ + err = PCAP_ERROR_NO_SUCH_DEVICE; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "SIOCGIFFLAGS on %s failed: %s", + ifr.ifr_name, pcap_strerror(errno)); + } else { + /* + * The underlying "enN" device + * exists, but there's no + * corresponding "wltN" device; + * that means that the "enN" + * device doesn't support + * monitor mode, probably because + * it's an Ethernet device rather + * than a wireless device. + */ + err = PCAP_ERROR_RFMON_NOTSUP; + } + close(fd); + } else { + /* + * We can't find out whether there's + * an underlying "enN" device, so + * just report "no such device". + */ + err = PCAP_ERROR_NO_SUCH_DEVICE; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "socket() failed: %s", + pcap_strerror(errno)); + } + return (err); + } +#endif + /* + * No such device. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s", + pcap_strerror(errno)); + return (PCAP_ERROR_NO_SUCH_DEVICE); + } else if (errno == ENETDOWN) { + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + return (PCAP_ERROR_IFACE_NOT_UP); + } else { + /* + * Some other error; fill in the error string, and + * return PCAP_ERROR. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + return (PCAP_ERROR); + } +} + +/* + * Default capture buffer size. + * 32K isn't very much for modern machines with fast networks; we + * pick .5M, as that's the maximum on at least some systems with BPF. + * + * However, on AIX 3.5, the larger buffer sized caused unrecoverable + * read failures under stress, so we leave it as 32K; yet another + * place where AIX's BPF is broken. + */ +#ifdef _AIX +#define DEFAULT_BUFSIZE 32768 +#else +#define DEFAULT_BUFSIZE 524288 +#endif + +static int +pcap_activate_bpf(pcap_t *p) +{ + int status = 0; + int fd; +#ifdef LIFNAMSIZ + char *zonesep; + struct lifreq ifr; + char *ifrname = ifr.lifr_name; + const size_t ifnamsiz = sizeof(ifr.lifr_name); +#else + struct ifreq ifr; + char *ifrname = ifr.ifr_name; + const size_t ifnamsiz = sizeof(ifr.ifr_name); +#endif + struct bpf_version bv; +#ifdef __APPLE__ + int sockfd; + char *wltdev = NULL; +#endif +#ifdef BIOCGDLTLIST + struct bpf_dltlist bdl; +#if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) + int new_dlt; +#endif +#endif /* BIOCGDLTLIST */ +#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) + u_int spoof_eth_src = 1; +#endif + u_int v; + struct bpf_insn total_insn; + struct bpf_program total_prog; + struct utsname osinfo; + +#ifdef HAVE_DAG_API + if (strstr(device, "dag")) { + return dag_open_live(device, snaplen, promisc, to_ms, ebuf); + } +#endif /* HAVE_DAG_API */ + +#ifdef BIOCGDLTLIST + memset(&bdl, 0, sizeof(bdl)); + int have_osinfo = 0; +#ifdef HAVE_ZEROCOPY_BPF + struct bpf_zbuf bz; + u_int bufmode, zbufmax; +#endif + + fd = bpf_open(p); + if (fd < 0) { + status = fd; + goto bad; + } + + p->fd = fd; + + if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + if (bv.bv_major != BPF_MAJOR_VERSION || + bv.bv_minor < BPF_MINOR_VERSION) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "kernel bpf filter out of date"); + status = PCAP_ERROR; + goto bad; + } + +#if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) + /* + * Check if the given source network device has a '/' separated + * zonename prefix string. The zonename prefixed source device + * can be used by libpcap consumers to capture network traffic + * in non-global zones from the global zone on Solaris 11 and + * above. If the zonename prefix is present then we strip the + * prefix and pass the zone ID as part of lifr_zoneid. + */ + if ((zonesep = strchr(p->opt.source, '/')) != NULL) { + char zonename[ZONENAME_MAX]; + int znamelen; + char *lnamep; + + znamelen = zonesep - p->opt.source; + (void) strlcpy(zonename, p->opt.source, znamelen + 1); + lnamep = strdup(zonesep + 1); + ifr.lifr_zoneid = getzoneidbyname(zonename); + free(p->opt.source); + p->opt.source = lnamep; + } +#endif + + p->md.device = strdup(p->opt.source); + if (p->md.device == NULL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + + /* + * Try finding a good size for the buffer; 32768 may be too + * big, so keep cutting it in half until we find a size + * that works, or run out of sizes to try. If the default + * is larger, don't make it smaller. + * + * XXX - there should be a user-accessible hook to set the + * initial buffer size. + * Attempt to find out the version of the OS on which we're running. + */ + if (uname(&osinfo) == 0) + have_osinfo = 1; + +#ifdef __APPLE__ + /* + * See comment in pcap_can_set_rfmon_bpf() for an explanation + * of why we check the version number. + */ + if (p->opt.rfmon) { + if (have_osinfo) { + /* + * We assume osinfo.sysname is "Darwin", because + * __APPLE__ is defined. We just check the version. + */ + if (osinfo.release[0] < '8' && + osinfo.release[1] == '.') { + /* + * 10.3 (Darwin 7.x) or earlier. + */ + status = PCAP_ERROR_RFMON_NOTSUP; + goto bad; + } + if (osinfo.release[0] == '8' && + osinfo.release[1] == '.') { + /* + * 10.4 (Darwin 8.x). s/en/wlt/ + */ + if (strncmp(p->opt.source, "en", 2) != 0) { + /* + * Not an enN device; check + * whether the device even exists. + */ + sockfd = socket(AF_INET, SOCK_DGRAM, 0); + if (sockfd != -1) { + strlcpy(ifrname, + p->opt.source, ifnamsiz); + if (ioctl(sockfd, SIOCGIFFLAGS, + (char *)&ifr) < 0) { + /* + * We assume this + * failed because + * the underlying + * device doesn't + * exist. + */ + status = PCAP_ERROR_NO_SUCH_DEVICE; + snprintf(p->errbuf, + PCAP_ERRBUF_SIZE, + "SIOCGIFFLAGS failed: %s", + pcap_strerror(errno)); + } else + status = PCAP_ERROR_RFMON_NOTSUP; + close(sockfd); + } else { + /* + * We can't find out whether + * the device exists, so just + * report "no such device". + */ + status = PCAP_ERROR_NO_SUCH_DEVICE; + snprintf(p->errbuf, + PCAP_ERRBUF_SIZE, + "socket() failed: %s", + pcap_strerror(errno)); + } + goto bad; + } + wltdev = malloc(strlen(p->opt.source) + 2); + if (wltdev == NULL) { + (void)snprintf(p->errbuf, + PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + strcpy(wltdev, "wlt"); + strcat(wltdev, p->opt.source + 2); + free(p->opt.source); + p->opt.source = wltdev; + } + /* + * Everything else is 10.5 or later; for those, + * we just open the enN device, and set the DLT. + */ + } + } +#endif /* __APPLE__ */ +#ifdef HAVE_ZEROCOPY_BPF + /* + * If the BPF extension to set buffer mode is present, try setting + * the mode to zero-copy. If that fails, use regular buffering. If + * it succeeds but other setup fails, return an error to the user. + */ + bufmode = BPF_BUFMODE_ZBUF; + if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { + /* + * We have zerocopy BPF; use it. + */ + p->md.zerocopy = 1; + + /* + * How to pick a buffer size: first, query the maximum buffer + * size supported by zero-copy. This also lets us quickly + * determine whether the kernel generally supports zero-copy. + * Then, if a buffer size was specified, use that, otherwise + * query the default buffer size, which reflects kernel + * policy for a desired default. Round to the nearest page + * size. + */ + if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s", + pcap_strerror(errno)); + goto bad; + } + + if (p->opt.buffer_size != 0) { + /* + * A buffer size was explicitly specified; use it. + */ + v = p->opt.buffer_size; + } else { + if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || + v < DEFAULT_BUFSIZE) + v = DEFAULT_BUFSIZE; + } +#ifndef roundup +#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ +#endif + p->md.zbufsize = roundup(v, getpagesize()); + if (p->md.zbufsize > zbufmax) + p->md.zbufsize = zbufmax; + p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, + MAP_ANON, -1, 0); + p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, + MAP_ANON, -1, 0); + if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s", + pcap_strerror(errno)); + goto bad; + } + memset(&bz, 0, sizeof(bz)); /* bzero() deprecated, replaced with memset() */ + bz.bz_bufa = p->md.zbuf1; + bz.bz_bufb = p->md.zbuf2; + bz.bz_buflen = p->md.zbufsize; + if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s", + pcap_strerror(errno)); + goto bad; + } + (void)strncpy(ifrname, p->opt.source, ifnamsiz); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + goto bad; + } + v = p->md.zbufsize - sizeof(struct bpf_zbuf_header); + } else +#endif + { + /* + * We don't have zerocopy BPF. + * Set the buffer size. + */ + if (p->opt.buffer_size != 0) { + /* + * A buffer size was explicitly specified; use it. + */ + if (ioctl(fd, BIOCSBLEN, + (caddr_t)&p->opt.buffer_size) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSBLEN: %s: %s", p->opt.source, + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + + /* + * Now bind to the device. + */ + (void)strncpy(ifrname, p->opt.source, ifnamsiz); +#ifdef BIOCSETLIF + if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) < 0) +#else + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) +#endif + { + status = check_setif_failure(p, errno); + goto bad; + } + } else { + /* + * No buffer size was explicitly specified. + * + * Try finding a good size for the buffer; + * DEFAULT_BUFSIZE may be too big, so keep + * cutting it in half until we find a size + * that works, or run out of sizes to try. + * If the default is larger, don't make it smaller. + */ + if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || + v < DEFAULT_BUFSIZE) + v = DEFAULT_BUFSIZE; + for ( ; v != 0; v >>= 1) { + /* + * Ignore the return value - this is because the + * call fails on BPF systems that don't have + * kernel malloc. And if the call fails, it's + * no big deal, we just continue to use the + * standard buffer size. + */ + (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); + + (void)strncpy(ifrname, p->opt.source, ifnamsiz); +#ifdef BIOCSETLIF + if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) >= 0) +#else + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) +#endif + break; /* that size worked; we're done */ + + if (errno != ENOBUFS) { + status = check_setif_failure(p, errno); + goto bad; + } + } + + if (v == 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSBLEN: %s: No buffer size worked", + p->opt.source); + status = PCAP_ERROR; + goto bad; + } + } + } +#endif + + /* Get the data link layer type. */ + if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + +#ifdef _AIX + /* + * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. + */ + switch (v) { + + case IFT_ETHER: + case IFT_ISO88023: + v = DLT_EN10MB; + break; + + case IFT_FDDI: + v = DLT_FDDI; + break; + + case IFT_ISO88025: + v = DLT_IEEE802; + break; + + case IFT_LOOP: + v = DLT_NULL; + break; + + default: + /* + * We don't know what to map this to yet. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", + v); + status = PCAP_ERROR; + goto bad; + } +#endif +#if _BSDI_VERSION - 0 >= 199510 + /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */ + switch (v) { + + case DLT_SLIP: + v = DLT_SLIP_BSDOS; + break; + + case DLT_PPP: + v = DLT_PPP_BSDOS; + break; + + case 11: /*DLT_FR*/ + v = DLT_FRELAY; + break; + + case 12: /*DLT_C_HDLC*/ + v = DLT_CHDLC; + break; + } +#endif + +#ifdef BIOCGDLTLIST + /* + * We know the default link type -- now determine all the DLTs + * this interface supports. If this fails with EINVAL, it's + * not fatal; we just don't get to use the feature later. + */ + if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { + status = PCAP_ERROR; + goto bad; + } + p->dlt_count = bdl.bfl_len; + p->dlt_list = bdl.bfl_list; + +#ifdef __APPLE__ + /* + * Monitor mode fun, continued. + * + * For 10.5 and, we're assuming, later releases, as noted above, + * 802.1 adapters that support monitor mode offer both DLT_EN10MB, + * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information + * DLT_ value. Choosing one of the 802.11 DLT_ values will turn + * monitor mode on. + * + * Therefore, if the user asked for monitor mode, we filter out + * the DLT_EN10MB value, as you can't get that in monitor mode, + * and, if the user didn't ask for monitor mode, we filter out + * the 802.11 DLT_ values, because selecting those will turn + * monitor mode on. Then, for monitor mode, if an 802.11-plus- + * radio DLT_ value is offered, we try to select that, otherwise + * we try to select DLT_IEEE802_11. + */ + if (have_osinfo) { + if (isdigit((unsigned)osinfo.release[0]) && + (osinfo.release[0] == '9' || + isdigit((unsigned)osinfo.release[1]))) { + /* + * 10.5 (Darwin 9.x), or later. + */ + new_dlt = find_802_11(&bdl); + if (new_dlt != -1) { + /* + * We have at least one 802.11 DLT_ value, + * so this is an 802.11 interface. + * new_dlt is the best of the 802.11 + * DLT_ values in the list. + */ + if (p->opt.rfmon) { + /* + * Our caller wants monitor mode. + * Purge DLT_EN10MB from the list + * of link-layer types, as selecting + * it will keep monitor mode off. + */ + remove_en(p); + + /* + * If the new mode we want isn't + * the default mode, attempt to + * select the new mode. + */ + if (new_dlt != v) { + if (ioctl(p->fd, BIOCSDLT, + &new_dlt) != -1) { + /* + * We succeeded; + * make this the + * new DLT_ value. + */ + v = new_dlt; + } + } + } else { + /* + * Our caller doesn't want + * monitor mode. Unless this + * is being done by pcap_open_live(), + * purge the 802.11 link-layer types + * from the list, as selecting + * one of them will turn monitor + * mode on. + */ + if (!p->oldstyle) + remove_802_11(p); + } + } else { + if (p->opt.rfmon) { + /* + * The caller requested monitor + * mode, but we have no 802.11 + * link-layer types, so they + * can't have it. + */ + status = PCAP_ERROR_RFMON_NOTSUP; + goto bad; + } + } + } + } +#elif defined(HAVE_BSD_IEEE80211) + /* + * *BSD with the new 802.11 ioctls. + * Do we want monitor mode? + */ + if (p->opt.rfmon) { + /* + * Try to put the interface into monitor mode. + */ + status = monitor_mode(p, 1); + if (status != 0) { + /* + * We failed. + */ + goto bad; + } + + /* + * We're in monitor mode. + * Try to find the best 802.11 DLT_ value and, if we + * succeed, try to switch to that mode if we're not + * already in that mode. + */ + new_dlt = find_802_11(&bdl); + if (new_dlt != -1) { + /* + * We have at least one 802.11 DLT_ value. + * new_dlt is the best of the 802.11 + * DLT_ values in the list. + * + * If the new mode we want isn't the default mode, + * attempt to select the new mode. + */ + if (new_dlt != v) { + if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { + /* + * We succeeded; make this the + * new DLT_ value. + */ + v = new_dlt; + } + } + } + } +#endif /* various platforms */ +#endif /* BIOCGDLTLIST */ + + /* + * If this is an Ethernet device, and we don't have a DLT_ list, + * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give + * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to + * do, but there's not much we can do about that without finding + * some other way of determining whether it's an Ethernet or 802.11 + * device.) + */ + if (v == DLT_EN10MB && p->dlt_count == 0) { + p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); + /* + * If that fails, just leave the list empty. + */ + if (p->dlt_list != NULL) { + p->dlt_list[0] = DLT_EN10MB; + p->dlt_list[1] = DLT_DOCSIS; + p->dlt_count = 2; + } + } +#ifdef PCAP_FDDIPAD + if (v == DLT_FDDI) + p->fddipad = PCAP_FDDIPAD; + else + p->fddipad = 0; +#endif + p->linktype = v; + +#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) + /* + * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so + * the link-layer source address isn't forcibly overwritten. + * (Should we ignore errors? Should we do this only if + * we're open for writing?) + * + * XXX - I seem to remember some packet-sending bug in some + * BSDs - check CVS log for "bpf.c"? + */ + if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { + (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSHDRCMPLT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } +#endif + /* set timeout */ +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.timeout != 0 && !p->md.zerocopy) { +#else + if (p->md.timeout) { +#endif + /* + * XXX - is this seconds/nanoseconds in AIX? + * (Treating it as such doesn't fix the timeout + * problem described below.) + * + * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in + * 64-bit userland - it takes, as an argument, a + * "struct BPF_TIMEVAL", which has 32-bit tv_sec + * and tv_usec, rather than a "struct timeval". + * + * If this platform defines "struct BPF_TIMEVAL", + * we check whether the structure size in BIOCSRTIMEOUT + * is that of a "struct timeval" and, if not, we use + * a "struct BPF_TIMEVAL" rather than a "struct timeval". + * (That way, if the bug is fixed in a future release, + * we will still do the right thing.) + */ + struct timeval to; +#ifdef HAVE_STRUCT_BPF_TIMEVAL + struct BPF_TIMEVAL bpf_to; + + if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) { + bpf_to.tv_sec = p->md.timeout / 1000; + bpf_to.tv_usec = (p->md.timeout * 1000) % 1000000; + if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + } else { +#endif + to.tv_sec = p->md.timeout / 1000; + to.tv_usec = (p->md.timeout * 1000) % 1000000; + if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } +#ifdef HAVE_STRUCT_BPF_TIMEVAL + } +#endif + } + +#ifdef _AIX +#ifdef BIOCIMMEDIATE + /* + * Darren Reed notes that + * + * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the + * timeout appears to be ignored and it waits until the buffer + * is filled before returning. The result of not having it + * set is almost worse than useless if your BPF filter + * is reducing things to only a few packets (i.e. one every + * second or so). + * + * so we turn BIOCIMMEDIATE mode on if this is AIX. + * + * We don't turn it on for other platforms, as that means we + * get woken up for every packet, which may not be what we want; + * in the Winter 1993 USENIX paper on BPF, they say: + * + * Since a process might want to look at every packet on a + * network and the time between packets can be only a few + * microseconds, it is not possible to do a read system call + * per packet and BPF must collect the data from several + * packets and return it as a unit when the monitoring + * application does a read. + * + * which I infer is the reason for the timeout - it means we + * wait that amount of time, in the hopes that more packets + * will arrive and we'll get them all with one read. + * + * Setting BIOCIMMEDIATE mode on FreeBSD (and probably other + * BSDs) causes the timeout to be ignored. + * + * On the other hand, some platforms (e.g., Linux) don't support + * timeouts, they just hand stuff to you as soon as it arrives; + * if that doesn't cause a problem on those platforms, it may + * be OK to have BIOCIMMEDIATE mode on BSD as well. + * + * (Note, though, that applications may depend on the read + * completing, even if no packets have arrived, when the timeout + * expires, e.g. GUI applications that have to check for input + * while waiting for packets to arrive; a non-zero timeout + * prevents "select()" from working right on FreeBSD and + * possibly other BSDs, as the timer doesn't start until a + * "read()" is done, so the timer isn't in effect if the + * application is blocked on a "select()", and the "select()" + * doesn't get woken up for a BPF device until the buffer + * fills up.) + */ + v = 1; + if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } +#endif /* BIOCIMMEDIATE */ +#endif /* _AIX */ + + if (p->opt.promisc) { + /* set promiscuous mode, just warn if it fails */ + if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", + pcap_strerror(errno)); + status = PCAP_WARNING_PROMISC_NOTSUP; + } + } + + if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + p->bufsize = v; +#ifdef HAVE_ZEROCOPY_BPF + if (!p->md.zerocopy) { +#endif + p->buffer = (u_char *)malloc(p->bufsize); + if (p->buffer == NULL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } +#ifdef _AIX + /* For some strange reason this seems to prevent the EFAULT + * problems we have experienced from AIX BPF. */ + memset(p->buffer, 0x0, p->bufsize); +#endif +#ifdef HAVE_ZEROCOPY_BPF + } +#endif + + /* + * If there's no filter program installed, there's + * no indication to the kernel of what the snapshot + * length should be, so no snapshotting is done. + * + * Therefore, when we open the device, we install + * an "accept everything" filter with the specified + * snapshot length. + */ + total_insn.code = (u_short)(BPF_RET | BPF_K); + total_insn.jt = 0; + total_insn.jf = 0; + total_insn.k = p->snapshot; + + total_prog.bf_len = 1; + total_prog.bf_insns = &total_insn; + if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + + /* + * On most BPF platforms, either you can do a "select()" or + * "poll()" on a BPF file descriptor and it works correctly, + * or you can do it and it will return "readable" if the + * hold buffer is full but not if the timeout expires *and* + * a non-blocking read will, if the hold buffer is empty + * but the store buffer isn't empty, rotate the buffers + * and return what packets are available. + * + * In the latter case, the fact that a non-blocking read + * will give you the available packets means you can work + * around the failure of "select()" and "poll()" to wake up + * and return "readable" when the timeout expires by using + * the timeout as the "select()" or "poll()" timeout, putting + * the BPF descriptor into non-blocking mode, and read from + * it regardless of whether "select()" reports it as readable + * or not. + * + * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" + * won't wake up and return "readable" if the timer expires + * and non-blocking reads return EWOULDBLOCK if the hold + * buffer is empty, even if the store buffer is non-empty. + * + * This means the workaround in question won't work. + * + * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" + * to -1, which means "sorry, you can't use 'select()' or 'poll()' + * here". On all other BPF platforms, we set it to the FD for + * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking + * read will, if the hold buffer is empty and the store buffer + * isn't empty, rotate the buffers and return what packets are + * there (and in sufficiently recent versions of OpenBSD + * "select()" and "poll()" should work correctly). + * + * XXX - what about AIX? + */ + p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ + if (have_osinfo) { + /* + * We can check what OS this is. + */ + if (strcmp(osinfo.sysname, "FreeBSD") == 0) { + if (strncmp(osinfo.release, "4.3-", 4) == 0 || + strncmp(osinfo.release, "4.4-", 4) == 0) + p->selectable_fd = -1; + } + } + + p->read_op = pcap_read_bpf; + p->inject_op = pcap_inject_bpf; + p->setfilter_op = pcap_setfilter_bpf; + p->setdirection_op = pcap_setdirection_bpf; + p->set_datalink_op = pcap_set_datalink_bpf; + p->getnonblock_op = pcap_getnonblock_bpf; + p->setnonblock_op = pcap_setnonblock_bpf; + p->stats_op = pcap_stats_bpf; + p->cleanup_op = pcap_cleanup_bpf; + + return (status); + bad: + pcap_cleanup_bpf(p); + return (status); +} + +int +pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) +{ + return (0); +} + +#ifdef HAVE_BSD_IEEE80211 +static int +monitor_mode(pcap_t *p, int set) +{ + int sock; + struct ifmediareq req; + int *media_list; + int i; + int can_do; + struct ifreq ifr; + + sock = socket(AF_INET, SOCK_DGRAM, 0); + if (sock == -1) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + memset(&req, 0, sizeof req); + strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name); + + /* + * Find out how many media types we have. + */ + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { + /* + * Can't get the media types. + */ + switch (errno) { + + case ENXIO: + /* + * There's no such device. + */ + close(sock); + return (PCAP_ERROR_NO_SUCH_DEVICE); + + case EINVAL: + /* + * Interface doesn't support SIOC{G,S}IFMEDIA. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + + default: + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "SIOCGIFMEDIA 1: %s", pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + } + if (req.ifm_count == 0) { + /* + * No media types. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + } + + /* + * Allocate a buffer to hold all the media types, and + * get the media types. + */ + media_list = malloc(req.ifm_count * sizeof(int)); + if (media_list == NULL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + req.ifm_ulist = media_list; + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s", + pcap_strerror(errno)); + free(media_list); + close(sock); + return (PCAP_ERROR); + } + + /* + * Look for an 802.11 "automatic" media type. + * We assume that all 802.11 adapters have that media type, + * and that it will carry the monitor mode supported flag. + */ + can_do = 0; + for (i = 0; i < req.ifm_count; i++) { + if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 + && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { + /* OK, does it do monitor mode? */ + if (media_list[i] & IFM_IEEE80211_MONITOR) { + can_do = 1; + break; + } + } + } + free(media_list); + if (!can_do) { + /* + * This adapter doesn't support monitor mode. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + } + + if (set) { + /* + * Don't just check whether we can enable monitor mode, + * do so, if it's not already enabled. + */ + if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { + /* + * Monitor mode isn't currently on, so turn it on, + * and remember that we should turn it off when the + * pcap_t is closed. + */ + + /* + * If we haven't already done so, arrange to have + * "pcap_close_all()" called when we exit. + */ + if (!pcap_do_addexit(p)) { + /* + * "atexit()" failed; don't put the interface + * in monitor mode, just give up. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "atexit failed"); + close(sock); + return (PCAP_ERROR); + } + memset(&ifr, 0, sizeof(ifr)); + (void)strncpy(ifr.ifr_name, p->opt.source, + sizeof(ifr.ifr_name)); + ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; + if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "SIOCSIFMEDIA: %s", pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + + p->md.must_do_on_close |= MUST_CLEAR_RFMON; + + /* + * Add this to the list of pcaps to close when we exit. + */ + pcap_add_to_pcaps_to_close(p); + } + } + return (0); +} +#endif /* HAVE_BSD_IEEE80211 */ + +#if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) +/* + * Check whether we have any 802.11 link-layer types; return the best + * of the 802.11 link-layer types if we find one, and return -1 + * otherwise. + * + * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the + * best 802.11 link-layer type; any of the other 802.11-plus-radio + * headers are second-best; 802.11 with no radio information is + * the least good. + */ +static int +find_802_11(struct bpf_dltlist *bdlp) +{ + int new_dlt; + int i; + + /* + * Scan the list of DLT_ values, looking for 802.11 values, + * and, if we find any, choose the best of them. + */ + new_dlt = -1; + for (i = 0; i < bdlp->bfl_len; i++) { + switch (bdlp->bfl_list[i]) { + + case DLT_IEEE802_11: + /* + * 802.11, but no radio. + * + * Offer this, and select it as the new mode + * unless we've already found an 802.11 + * header with radio information. + */ + if (new_dlt == -1) + new_dlt = bdlp->bfl_list[i]; + break; + + case DLT_PRISM_HEADER: + case DLT_AIRONET_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + /* + * 802.11 with radio, but not radiotap. + * + * Offer this, and select it as the new mode + * unless we've already found the radiotap DLT_. + */ + if (new_dlt != DLT_IEEE802_11_RADIO) + new_dlt = bdlp->bfl_list[i]; + break; + + case DLT_IEEE802_11_RADIO: + /* + * 802.11 with radiotap. + * + * Offer this, and select it as the new mode. + */ + new_dlt = bdlp->bfl_list[i]; + break; + + default: + /* + * Not 802.11. + */ + break; + } + } + + return (new_dlt); +} +#endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ + +#if defined(__APPLE__) && defined(BIOCGDLTLIST) +/* + * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode, + * and DLT_EN10MB isn't supported in monitor mode. + */ +static void +remove_en(pcap_t *p) +{ + int i, j; + + /* + * Scan the list of DLT_ values and discard DLT_EN10MB. + */ + j = 0; + for (i = 0; i < p->dlt_count; i++) { + switch (p->dlt_list[i]) { + + case DLT_EN10MB: + /* + * Don't offer this one. + */ + continue; + + default: + /* + * Just copy this mode over. + */ + break; + } + + /* + * Copy this DLT_ value to its new position. + */ + p->dlt_list[j] = p->dlt_list[i]; + j++; + } + + /* + * Set the DLT_ count to the number of entries we copied. + */ + p->dlt_count = j; +} + +/* + * Remove 802.11 link-layer types from the list of DLT_ values, as + * we're not in monitor mode, and those DLT_ values will switch us + * to monitor mode. + */ +static void +remove_802_11(pcap_t *p) +{ + int i, j; + + /* + * Scan the list of DLT_ values and discard 802.11 values. + */ + j = 0; + for (i = 0; i < p->dlt_count; i++) { + switch (p->dlt_list[i]) { + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_AIRONET_HEADER: + case DLT_IEEE802_11_RADIO: + case DLT_IEEE802_11_RADIO_AVS: + /* + * 802.11. Don't offer this one. + */ + continue; + + default: + /* + * Just copy this mode over. + */ + break; + } + + /* + * Copy this DLT_ value to its new position. + */ + p->dlt_list[j] = p->dlt_list[i]; + j++; + } + + /* + * Set the DLT_ count to the number of entries we copied. + */ + p->dlt_count = j; +} +#endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ + +static int +pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) +{ + /* + * Free any user-mode filter we might happen to have installed. + */ + pcap_freecode(&p->fcode); + + /* + * Try to install the kernel filter. + */ + if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) { + /* + * It worked. + */ + p->md.use_bpf = 1; /* filtering in the kernel */ + + /* + * Discard any previously-received packets, as they might + * have passed whatever filter was formerly in effect, but + * might not pass this filter (BIOCSETF discards packets + * buffered in the kernel, so you can lose packets in any + * case). + */ + p->cc = 0; + return (0); + } + + /* + * We failed. + * + * If it failed with EINVAL, that's probably because the program + * is invalid or too big. Validate it ourselves; if we like it + * (we currently allow backward branches, to support protochain), + * run it in userland. (There's no notion of "too big" for + * userland.) + * + * Otherwise, just give up. + * XXX - if the copy of the program into the kernel failed, + * we will get EINVAL rather than, say, EFAULT on at least + * some kernels. + */ + if (errno != EINVAL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", + pcap_strerror(errno)); + return (-1); + } + + /* + * install_bpf_program() validates the program. + * + * XXX - what if we already have a filter in the kernel? + */ + if (install_bpf_program(p, fp) < 0) + return (-1); + p->md.use_bpf = 0; /* filtering in userland */ + return (0); +} + +/* + * Set direction flag: Which packets do we accept on a forwarding + * single device? IN, OUT or both? + */ +static int +pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) +{ +#if defined(BIOCSDIRECTION) + u_int direction; + + direction = (d == PCAP_D_IN) ? BPF_D_IN : + ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT); + if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) { + (void) snprintf(p->errbuf, sizeof(p->errbuf), + "Cannot set direction to %s: %s", + (d == PCAP_D_IN) ? "PCAP_D_IN" : + ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"), + strerror(errno)); + return (-1); + } + return (0); +#elif defined(BIOCSSEESENT) + u_int seesent; + + /* + * We don't support PCAP_D_OUT. + */ + if (d == PCAP_D_OUT) { + snprintf(p->errbuf, sizeof(p->errbuf), + "Setting direction to PCAP_D_OUT is not supported on BPF"); + return -1; + } + + seesent = (d == PCAP_D_INOUT); + if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) { + (void) snprintf(p->errbuf, sizeof(p->errbuf), + "Cannot set direction to %s: %s", + (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN", + strerror(errno)); + return (-1); + } + return (0); +#else + (void) snprintf(p->errbuf, sizeof(p->errbuf), + "This system doesn't support BIOCSSEESENT, so the direction can't be set"); + return (-1); +#endif +} + +static int +pcap_set_datalink_bpf(pcap_t *p, int dlt) +{ +#ifdef BIOCSDLT + if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) { + (void) snprintf(p->errbuf, sizeof(p->errbuf), + "Cannot set DLT %d: %s", dlt, strerror(errno)); + return (-1); + } +#endif + return (0); +} |