diff options
Diffstat (limited to 'mDNSResponder/mDNSPosix/mDNSUNP.c')
| -rwxr-xr-x | mDNSResponder/mDNSPosix/mDNSUNP.c | 719 |
1 files changed, 719 insertions, 0 deletions
diff --git a/mDNSResponder/mDNSPosix/mDNSUNP.c b/mDNSResponder/mDNSPosix/mDNSUNP.c new file mode 100755 index 00000000..b392fc74 --- /dev/null +++ b/mDNSResponder/mDNSPosix/mDNSUNP.c @@ -0,0 +1,719 @@ +/* -*- Mode: C; tab-width: 4 -*- + * + * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "mDNSUNP.h" + +#include <errno.h> +#include <assert.h> +#include <string.h> +#include <stdlib.h> +#include <sys/uio.h> +#include <sys/ioctl.h> +#include <signal.h> +#include <unistd.h> +#include <stdio.h> + +/* Some weird platforms derived from 4.4BSD Lite (e.g. EFI) need the ALIGN(P) + macro, usually defined in <sys/param.h> or someplace like that, to make sure the + CMSG_NXTHDR macro is well-formed. On such platforms, the symbol NEED_ALIGN_MACRO + should be set to the name of the header to include to get the ALIGN(P) macro. + */ +#ifdef NEED_ALIGN_MACRO +#include NEED_ALIGN_MACRO +#endif + +/* Solaris defined SIOCGIFCONF etc in <sys/sockio.h> but + other platforms don't even have that include file. So, + if we haven't yet got a definition, let's try to find + <sys/sockio.h>. + */ + +#ifndef SIOCGIFCONF + #include <sys/sockio.h> +#endif + +/* sockaddr_dl is only referenced if we're using IP_RECVIF, + so only include the header in that case. + */ + +#ifdef IP_RECVIF + #include <net/if_dl.h> +#endif + +#if defined(AF_INET6) && HAVE_IPV6 && !HAVE_LINUX +#include <net/if_var.h> +#include <netinet/in_var.h> +// Note: netinet/in_var.h implicitly includes netinet6/in6_var.h for us +#endif + +#if defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX +#include <netdb.h> +#include <arpa/inet.h> + +/* Converts a prefix length to IPv6 network mask */ +void plen_to_mask(int plen, char *addr) { + int i; + int colons=7; /* Number of colons in IPv6 address */ + int bits_in_block=16; /* Bits per IPv6 block */ + for(i=0; i<=colons; i++) { + int block, ones=0xffff, ones_in_block; + if (plen>bits_in_block) ones_in_block=bits_in_block; + else ones_in_block=plen; + block = ones & (ones << (bits_in_block-ones_in_block)); + i==0 ? sprintf(addr, "%x", block) : sprintf(addr, "%s:%x", addr, block); + plen -= ones_in_block; + } +} + +/* Gets IPv6 interface information from the /proc filesystem in linux*/ +struct ifi_info *get_ifi_info_linuxv6(int family, int doaliases) +{ + struct ifi_info *ifi, *ifihead, **ifipnext, *ifipold, **ifiptr; + FILE *fp; + char addr[8][5]; + int flags, myflags, index, plen, scope; + char ifname[9], lastname[IFNAMSIZ]; + char addr6[32+7+1]; /* don't forget the seven ':' */ + struct addrinfo hints, *res0; + struct sockaddr_in6 *sin6; + struct in6_addr *addrptr; + int err; + int sockfd = -1; + struct ifreq ifr; + + res0=NULL; + ifihead = NULL; + ifipnext = &ifihead; + lastname[0] = 0; + + if ((fp = fopen(PROC_IFINET6_PATH, "r")) != NULL) { + sockfd = socket(AF_INET6, SOCK_DGRAM, 0); + if (sockfd < 0) { + goto gotError; + } + while (fscanf(fp, + "%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %8s\n", + addr[0],addr[1],addr[2],addr[3], + addr[4],addr[5],addr[6],addr[7], + &index, &plen, &scope, &flags, ifname) != EOF) { + + myflags = 0; + if (strncmp(lastname, ifname, IFNAMSIZ) == 0) { + if (doaliases == 0) + continue; /* already processed this interface */ + myflags = IFI_ALIAS; + } + memcpy(lastname, ifname, IFNAMSIZ); + ifi = (struct ifi_info*)calloc(1, sizeof(struct ifi_info)); + if (ifi == NULL) { + goto gotError; + } + + ifipold = *ifipnext; /* need this later */ + ifiptr = ifipnext; + *ifipnext = ifi; /* prev points to this new one */ + ifipnext = &ifi->ifi_next; /* pointer to next one goes here */ + + sprintf(addr6, "%s:%s:%s:%s:%s:%s:%s:%s", + addr[0],addr[1],addr[2],addr[3], + addr[4],addr[5],addr[6],addr[7]); + + /* Add address of the interface */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_INET6; + hints.ai_flags = AI_NUMERICHOST; + err = getaddrinfo(addr6, NULL, &hints, &res0); + if (err) { + goto gotError; + } + ifi->ifi_addr = calloc(1, sizeof(struct sockaddr_in6)); + if (ifi->ifi_addr == NULL) { + goto gotError; + } + memcpy(ifi->ifi_addr, res0->ai_addr, sizeof(struct sockaddr_in6)); + + /* Add netmask of the interface */ + char ipv6addr[INET6_ADDRSTRLEN]; + plen_to_mask(plen, ipv6addr); + ifi->ifi_netmask = calloc(1, sizeof(struct sockaddr_in6)); + if (ifi->ifi_addr == NULL) { + goto gotError; + } + sin6=calloc(1, sizeof(struct sockaddr_in6)); + addrptr=calloc(1, sizeof(struct in6_addr)); + inet_pton(family, ipv6addr, addrptr); + sin6->sin6_family=family; + sin6->sin6_addr=*addrptr; + sin6->sin6_scope_id=scope; + memcpy(ifi->ifi_netmask, sin6, sizeof(struct sockaddr_in6)); + free(sin6); + + + /* Add interface name */ + memcpy(ifi->ifi_name, ifname, IFI_NAME); + + /* Add interface index */ + ifi->ifi_index = index; + + /* Add interface flags*/ + memcpy(ifr.ifr_name, ifname, IFNAMSIZ); + if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) { + if (errno == EADDRNOTAVAIL) { + /* + * If the main interface is configured with no IP address but + * an alias interface exists with an IP address, you get + * EADDRNOTAVAIL for the main interface + */ + free(ifi->ifi_addr); + free(ifi); + ifipnext = ifiptr; + *ifipnext = ifipold; + continue; + } else { + goto gotError; + } + } + ifi->ifi_flags = ifr.ifr_flags; + freeaddrinfo(res0); + res0=NULL; + } + } + goto done; + +gotError: + if (ifihead != NULL) { + free_ifi_info(ifihead); + ifihead = NULL; + } + if (res0 != NULL) { + freeaddrinfo(res0); + res0=NULL; + } +done: + if (sockfd != -1) { + assert(close(sockfd) == 0); + } + return(ifihead); /* pointer to first structure in linked list */ +} +#endif // defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX + +struct ifi_info *get_ifi_info(int family, int doaliases) +{ + int junk; + struct ifi_info *ifi, *ifihead, **ifipnext, *ifipold, **ifiptr; + int sockfd, sockf6, len, lastlen, flags, myflags; +#ifdef NOT_HAVE_IF_NAMETOINDEX + int index = 200; +#endif + char *ptr, *buf, lastname[IFNAMSIZ], *cptr; + struct ifconf ifc; + struct ifreq *ifr, ifrcopy; + struct sockaddr_in *sinptr; + +#if defined(AF_INET6) && HAVE_IPV6 + struct sockaddr_in6 *sinptr6; +#endif + +#if defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX + if (family == AF_INET6) return get_ifi_info_linuxv6(family, doaliases); +#endif + + sockfd = -1; + sockf6 = -1; + buf = NULL; + ifihead = NULL; + + sockfd = socket(AF_INET, SOCK_DGRAM, 0); + if (sockfd < 0) { + goto gotError; + } + + lastlen = 0; + len = 100 * sizeof(struct ifreq); /* initial buffer size guess */ + for ( ; ; ) { + buf = (char*)malloc(len); + if (buf == NULL) { + goto gotError; + } + ifc.ifc_len = len; + ifc.ifc_buf = buf; + if (ioctl(sockfd, SIOCGIFCONF, &ifc) < 0) { + if (errno != EINVAL || lastlen != 0) { + goto gotError; + } + } else { + if (ifc.ifc_len == lastlen) + break; /* success, len has not changed */ + lastlen = ifc.ifc_len; + } + len += 10 * sizeof(struct ifreq); /* increment */ + free(buf); + } + ifihead = NULL; + ifipnext = &ifihead; + lastname[0] = 0; +/* end get_ifi_info1 */ + +/* include get_ifi_info2 */ + for (ptr = buf; ptr < buf + ifc.ifc_len; ) { + ifr = (struct ifreq *) ptr; + + /* Advance to next one in buffer */ + if (sizeof(struct ifreq) > sizeof(ifr->ifr_name) + GET_SA_LEN(ifr->ifr_addr)) + ptr += sizeof(struct ifreq); + else + ptr += sizeof(ifr->ifr_name) + GET_SA_LEN(ifr->ifr_addr); + +// fprintf(stderr, "intf %p name=%s AF=%d\n", index, ifr->ifr_name, ifr->ifr_addr.sa_family); + + if (ifr->ifr_addr.sa_family != family) + continue; /* ignore if not desired address family */ + + myflags = 0; + if ( (cptr = strchr(ifr->ifr_name, ':')) != NULL) + *cptr = 0; /* replace colon will null */ + if (strncmp(lastname, ifr->ifr_name, IFNAMSIZ) == 0) { + if (doaliases == 0) + continue; /* already processed this interface */ + myflags = IFI_ALIAS; + } + memcpy(lastname, ifr->ifr_name, IFNAMSIZ); + + ifrcopy = *ifr; + if (ioctl(sockfd, SIOCGIFFLAGS, &ifrcopy) < 0) { + goto gotError; + } + + flags = ifrcopy.ifr_flags; + if ((flags & IFF_UP) == 0) + continue; /* ignore if interface not up */ + + ifi = (struct ifi_info*)calloc(1, sizeof(struct ifi_info)); + if (ifi == NULL) { + goto gotError; + } + ifipold = *ifipnext; /* need this later */ + ifiptr = ifipnext; + *ifipnext = ifi; /* prev points to this new one */ + ifipnext = &ifi->ifi_next; /* pointer to next one goes here */ + + ifi->ifi_flags = flags; /* IFF_xxx values */ + ifi->ifi_myflags = myflags; /* IFI_xxx values */ +#ifndef NOT_HAVE_IF_NAMETOINDEX + ifi->ifi_index = if_nametoindex(ifr->ifr_name); +#else + ifrcopy = *ifr; +#ifdef SIOCGIFINDEX + if ( 0 >= ioctl(sockfd, SIOCGIFINDEX, &ifrcopy)) + ifi->ifi_index = ifrcopy.ifr_index; + else +#endif + ifi->ifi_index = index++; /* SIOCGIFINDEX is broken on Solaris 2.5ish, so fake it */ +#endif + memcpy(ifi->ifi_name, ifr->ifr_name, IFI_NAME); + ifi->ifi_name[IFI_NAME-1] = '\0'; +/* end get_ifi_info2 */ +/* include get_ifi_info3 */ + switch (ifr->ifr_addr.sa_family) { + case AF_INET: + sinptr = (struct sockaddr_in *) &ifr->ifr_addr; + if (ifi->ifi_addr == NULL) { + ifi->ifi_addr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); + if (ifi->ifi_addr == NULL) { + goto gotError; + } + memcpy(ifi->ifi_addr, sinptr, sizeof(struct sockaddr_in)); + +#ifdef SIOCGIFNETMASK + if (ioctl(sockfd, SIOCGIFNETMASK, &ifrcopy) < 0) { + if (errno == EADDRNOTAVAIL) { + /* + * If the main interface is configured with no IP address but + * an alias interface exists with an IP address, you get + * EADDRNOTAVAIL for the main interface + */ + free(ifi->ifi_addr); + free(ifi); + ifipnext = ifiptr; + *ifipnext = ifipold; + continue; + } else { + goto gotError; + } + } + + ifi->ifi_netmask = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); + if (ifi->ifi_netmask == NULL) goto gotError; + sinptr = (struct sockaddr_in *) &ifrcopy.ifr_addr; + /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ +#ifndef NOT_HAVE_SA_LEN + sinptr->sin_len = sizeof(struct sockaddr_in); +#endif + sinptr->sin_family = AF_INET; + memcpy(ifi->ifi_netmask, sinptr, sizeof(struct sockaddr_in)); +#endif + +#ifdef SIOCGIFBRDADDR + if (flags & IFF_BROADCAST) { + if (ioctl(sockfd, SIOCGIFBRDADDR, &ifrcopy) < 0) { + goto gotError; + } + sinptr = (struct sockaddr_in *) &ifrcopy.ifr_broadaddr; + /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ +#ifndef NOT_HAVE_SA_LEN + sinptr->sin_len = sizeof( struct sockaddr_in ); +#endif + sinptr->sin_family = AF_INET; + ifi->ifi_brdaddr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); + if (ifi->ifi_brdaddr == NULL) { + goto gotError; + } + memcpy(ifi->ifi_brdaddr, sinptr, sizeof(struct sockaddr_in)); + } +#endif + +#ifdef SIOCGIFDSTADDR + if (flags & IFF_POINTOPOINT) { + if (ioctl(sockfd, SIOCGIFDSTADDR, &ifrcopy) < 0) { + goto gotError; + } + sinptr = (struct sockaddr_in *) &ifrcopy.ifr_dstaddr; + /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ +#ifndef NOT_HAVE_SA_LEN + sinptr->sin_len = sizeof( struct sockaddr_in ); +#endif + sinptr->sin_family = AF_INET; + ifi->ifi_dstaddr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); + if (ifi->ifi_dstaddr == NULL) { + goto gotError; + } + memcpy(ifi->ifi_dstaddr, sinptr, sizeof(struct sockaddr_in)); + } +#endif + } + break; + +#if defined(AF_INET6) && HAVE_IPV6 + case AF_INET6: + sinptr6 = (struct sockaddr_in6 *) &ifr->ifr_addr; + if (ifi->ifi_addr == NULL) { + ifi->ifi_addr = calloc(1, sizeof(struct sockaddr_in6)); + if (ifi->ifi_addr == NULL) { + goto gotError; + } + + /* Some platforms (*BSD) inject the prefix in IPv6LL addresses */ + /* We need to strip that out */ + if (IN6_IS_ADDR_LINKLOCAL(&sinptr6->sin6_addr)) + sinptr6->sin6_addr.s6_addr[2] = sinptr6->sin6_addr.s6_addr[3] = 0; + memcpy(ifi->ifi_addr, sinptr6, sizeof(struct sockaddr_in6)); + +#ifdef SIOCGIFNETMASK_IN6 + { + struct in6_ifreq ifr6; + if (sockf6 == -1) + sockf6 = socket(AF_INET6, SOCK_DGRAM, 0); + memset(&ifr6, 0, sizeof(ifr6)); + memcpy(&ifr6.ifr_name, &ifr->ifr_name, sizeof(ifr6.ifr_name )); + memcpy(&ifr6.ifr_ifru.ifru_addr, &ifr->ifr_addr, sizeof(ifr6.ifr_ifru.ifru_addr)); + if (ioctl(sockf6, SIOCGIFNETMASK_IN6, &ifr6) < 0) { + if (errno == EADDRNOTAVAIL) { + /* + * If the main interface is configured with no IP address but + * an alias interface exists with an IP address, you get + * EADDRNOTAVAIL for the main interface + */ + free(ifi->ifi_addr); + free(ifi); + ifipnext = ifiptr; + *ifipnext = ifipold; + continue; + } else { + goto gotError; + } + } + ifi->ifi_netmask = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in6)); + if (ifi->ifi_netmask == NULL) goto gotError; + sinptr6 = (struct sockaddr_in6 *) &ifr6.ifr_ifru.ifru_addr; + memcpy(ifi->ifi_netmask, sinptr6, sizeof(struct sockaddr_in6)); + } +#endif + } + break; +#endif + + default: + break; + } + } + goto done; + +gotError: + if (ifihead != NULL) { + free_ifi_info(ifihead); + ifihead = NULL; + } + +done: + if (buf != NULL) { + free(buf); + } + if (sockfd != -1) { + junk = close(sockfd); + assert(junk == 0); + } + if (sockf6 != -1) { + junk = close(sockf6); + assert(junk == 0); + } + return(ifihead); /* pointer to first structure in linked list */ +} +/* end get_ifi_info3 */ + +/* include free_ifi_info */ +void +free_ifi_info(struct ifi_info *ifihead) +{ + struct ifi_info *ifi, *ifinext; + + for (ifi = ifihead; ifi != NULL; ifi = ifinext) { + if (ifi->ifi_addr != NULL) + free(ifi->ifi_addr); + if (ifi->ifi_netmask != NULL) + free(ifi->ifi_netmask); + if (ifi->ifi_brdaddr != NULL) + free(ifi->ifi_brdaddr); + if (ifi->ifi_dstaddr != NULL) + free(ifi->ifi_dstaddr); + ifinext = ifi->ifi_next; /* can't fetch ifi_next after free() */ + free(ifi); /* the ifi_info{} itself */ + } +} +/* end free_ifi_info */ + +ssize_t +recvfrom_flags(int fd, void *ptr, size_t nbytes, int *flagsp, + struct sockaddr *sa, socklen_t *salenptr, struct my_in_pktinfo *pktp, u_char *ttl) +{ + struct msghdr msg; + struct iovec iov[1]; + ssize_t n; + +#ifdef CMSG_FIRSTHDR + struct cmsghdr *cmptr; + union { + struct cmsghdr cm; + char control[1024]; + } control_un; + + *ttl = 255; // If kernel fails to provide TTL data then assume the TTL was 255 as it should be + + msg.msg_control = control_un.control; + msg.msg_controllen = sizeof(control_un.control); + msg.msg_flags = 0; +#else + memset(&msg, 0, sizeof(msg)); /* make certain msg_accrightslen = 0 */ +#endif /* CMSG_FIRSTHDR */ + + msg.msg_name = (char *) sa; + msg.msg_namelen = *salenptr; + iov[0].iov_base = (char *)ptr; + iov[0].iov_len = nbytes; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + if ( (n = recvmsg(fd, &msg, *flagsp)) < 0) + return(n); + + *salenptr = msg.msg_namelen; /* pass back results */ + if (pktp) { + /* 0.0.0.0, i/f = -1 */ + /* We set the interface to -1 so that the caller can + tell whether we returned a meaningful value or + just some default. Previously this code just + set the value to 0, but I'm concerned that 0 + might be a valid interface value. + */ + memset(pktp, 0, sizeof(struct my_in_pktinfo)); + pktp->ipi_ifindex = -1; + } +/* end recvfrom_flags1 */ + +/* include recvfrom_flags2 */ +#ifndef CMSG_FIRSTHDR + #warning CMSG_FIRSTHDR not defined. Will not be able to determine destination address, received interface, etc. + *flagsp = 0; /* pass back results */ + return(n); +#else + + *flagsp = msg.msg_flags; /* pass back results */ + if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) || + (msg.msg_flags & MSG_CTRUNC) || pktp == NULL) + return(n); + + for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL; + cmptr = CMSG_NXTHDR(&msg, cmptr)) { + +#ifdef IP_PKTINFO +#if in_pktinfo_definition_is_missing + struct in_pktinfo + { + int ipi_ifindex; + struct in_addr ipi_spec_dst; + struct in_addr ipi_addr; + }; +#endif + if (cmptr->cmsg_level == IPPROTO_IP && + cmptr->cmsg_type == IP_PKTINFO) { + struct in_pktinfo *tmp; + struct sockaddr_in *sin = (struct sockaddr_in*)&pktp->ipi_addr; + + tmp = (struct in_pktinfo *) CMSG_DATA(cmptr); + sin->sin_family = AF_INET; + sin->sin_addr = tmp->ipi_addr; + sin->sin_port = 0; + pktp->ipi_ifindex = tmp->ipi_ifindex; + continue; + } +#endif + +#ifdef IP_RECVDSTADDR + if (cmptr->cmsg_level == IPPROTO_IP && + cmptr->cmsg_type == IP_RECVDSTADDR) { + struct sockaddr_in *sin = (struct sockaddr_in*)&pktp->ipi_addr; + + sin->sin_family = AF_INET; + sin->sin_addr = *(struct in_addr*)CMSG_DATA(cmptr); + sin->sin_port = 0; + continue; + } +#endif + +#ifdef IP_RECVIF + if (cmptr->cmsg_level == IPPROTO_IP && + cmptr->cmsg_type == IP_RECVIF) { + struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr); +#ifndef HAVE_BROKEN_RECVIF_NAME + int nameLen = (sdl->sdl_nlen < IFI_NAME - 1) ? sdl->sdl_nlen : (IFI_NAME - 1); + strncpy(pktp->ipi_ifname, sdl->sdl_data, nameLen); +#endif + pktp->ipi_ifindex = sdl->sdl_index; +#ifdef HAVE_BROKEN_RECVIF_NAME + if (sdl->sdl_index == 0) { + pktp->ipi_ifindex = *(uint_t*)sdl; + } +#endif + assert(pktp->ipi_ifname[IFI_NAME - 1] == 0); + // null terminated because of memset above + continue; + } +#endif + +#ifdef IP_RECVTTL + if (cmptr->cmsg_level == IPPROTO_IP && + cmptr->cmsg_type == IP_RECVTTL) { + *ttl = *(u_char*)CMSG_DATA(cmptr); + continue; + } + else if (cmptr->cmsg_level == IPPROTO_IP && + cmptr->cmsg_type == IP_TTL) { // some implementations seem to send IP_TTL instead of IP_RECVTTL + *ttl = *(int*)CMSG_DATA(cmptr); + continue; + } +#endif + +#if defined(IPV6_PKTINFO) && HAVE_IPV6 + if (cmptr->cmsg_level == IPPROTO_IPV6 && + cmptr->cmsg_type == IPV6_2292_PKTINFO) { + struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&pktp->ipi_addr; + struct in6_pktinfo *ip6_info = (struct in6_pktinfo*)CMSG_DATA(cmptr); + + sin6->sin6_family = AF_INET6; +#ifndef NOT_HAVE_SA_LEN + sin6->sin6_len = sizeof(*sin6); +#endif + sin6->sin6_addr = ip6_info->ipi6_addr; + sin6->sin6_flowinfo = 0; + sin6->sin6_scope_id = 0; + sin6->sin6_port = 0; + pktp->ipi_ifindex = ip6_info->ipi6_ifindex; + continue; + } +#endif + +#if defined(IPV6_HOPLIMIT) && HAVE_IPV6 + if (cmptr->cmsg_level == IPPROTO_IPV6 && + cmptr->cmsg_type == IPV6_2292_HOPLIMIT) { + *ttl = *(int*)CMSG_DATA(cmptr); + continue; + } +#endif + assert(0); // unknown ancillary data + } + return(n); +#endif /* CMSG_FIRSTHDR */ +} + +// ********************************************************************************************** + +// daemonize the process. Adapted from "Unix Network Programming" vol 1 by Stevens, section 12.4. +// Returns 0 on success, -1 on failure. + +#ifdef NOT_HAVE_DAEMON +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/signal.h> + +int daemon(int nochdir, int noclose) +{ + switch (fork()) + { + case -1: return (-1); // Fork failed + case 0: break; // Child -- continue + default: _exit(0); // Parent -- exit + } + + if (setsid() == -1) return(-1); + + signal(SIGHUP, SIG_IGN); + + switch (fork()) // Fork again, primarily for reasons of Unix trivia + { + case -1: return (-1); // Fork failed + case 0: break; // Child -- continue + default: _exit(0); // Parent -- exit + } + + if (!nochdir) (void)chdir("/"); + umask(0); + + if (!noclose) + { + int fd = open("/dev/null", O_RDWR, 0); + if (fd != -1) + { + // Avoid unnecessarily duplicating a file descriptor to itself + if (fd != STDIN_FILENO) (void)dup2(fd, STDIN_FILENO); + if (fd != STDOUT_FILENO) (void)dup2(fd, STDOUT_FILENO); + if (fd != STDERR_FILENO) (void)dup2(fd, STDERR_FILENO); + if (fd != STDIN_FILENO && fd != STDOUT_FILENO && fd != STDERR_FILENO) + (void)close (fd); + } + } + return (0); +} +#endif /* NOT_HAVE_DAEMON */ |