diff options
Diffstat (limited to 'c/src/exec/libnetworking/netinet/ip_fw.c')
| -rw-r--r-- | c/src/exec/libnetworking/netinet/ip_fw.c | 1069 |
1 files changed, 0 insertions, 1069 deletions
diff --git a/c/src/exec/libnetworking/netinet/ip_fw.c b/c/src/exec/libnetworking/netinet/ip_fw.c deleted file mode 100644 index aeb09b0bbe..0000000000 --- a/c/src/exec/libnetworking/netinet/ip_fw.c +++ /dev/null @@ -1,1069 +0,0 @@ -/* - * Copyright (c) 1996 Alex Nash - * Copyright (c) 1993 Daniel Boulet - * Copyright (c) 1994 Ugen J.S.Antsilevich - * - * Redistribution and use in source forms, with and without modification, - * are permitted provided that this entire comment appears intact. - * - * Redistribution in binary form may occur without any restrictions. - * Obviously, it would be nice if you gave credit where credit is due - * but requiring it would be too onerous. - * - * This software is provided ``AS IS'' without any warranties of any kind. - * - * $Id$ - */ - -/* - * Implement IP packet firewall - */ - -#ifndef IPFIREWALL_MODULE -#include "opt_ipfw.h" -#endif - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/malloc.h> -#include <sys/mbuf.h> -#include <sys/queue.h> -#include <sys/kernel.h> -#include <sys/socket.h> -#include <sys/time.h> -#include <sys/sysctl.h> -#include <net/if.h> -#include <net/route.h> -#include <netinet/in.h> -#include <netinet/in_systm.h> -#include <netinet/ip.h> -#include <netinet/ip_var.h> -#include <netinet/ip_icmp.h> -#include <netinet/ip_fw.h> -#include <netinet/tcp.h> -#include <netinet/tcp_timer.h> -#include <netinet/tcp_var.h> -#include <netinet/tcpip.h> -#include <netinet/udp.h> - -static int fw_debug = 1; -#ifdef IPFIREWALL_VERBOSE -static int fw_verbose = 1; -#else -static int fw_verbose = 0; -#endif -#ifdef IPFIREWALL_VERBOSE_LIMIT -static int fw_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; -#else -static int fw_verbose_limit = 0; -#endif - -LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain; - -#ifdef SYSCTL_NODE -SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); -SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, &fw_debug, 0, ""); -SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw_verbose, 0, ""); -SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw_verbose_limit, 0, ""); -#endif - -#define dprintf(a) if (!fw_debug); else printf a - -#define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\ - (ntohl(a.s_addr)>>16)&0xFF,\ - (ntohl(a.s_addr)>>8)&0xFF,\ - (ntohl(a.s_addr))&0xFF); - -#define dprint_ip(a) if (!fw_debug); else print_ip(a) - -static int add_entry __P((struct ip_fw_head *chainptr, struct ip_fw *frwl)); -static int del_entry __P((struct ip_fw_head *chainptr, u_short number)); -static int zero_entry __P((struct mbuf *m)); -static struct ip_fw *check_ipfw_struct __P((struct ip_fw *m)); -static struct ip_fw *check_ipfw_mbuf __P((struct mbuf *fw)); -static int ipopts_match __P((struct ip *ip, struct ip_fw *f)); -static int port_match __P((u_short *portptr, int nports, u_short port, - int range_flag)); -static int tcpflg_match __P((struct tcphdr *tcp, struct ip_fw *f)); -static int icmptype_match __P((struct icmp * icmp, struct ip_fw * f)); -static void ipfw_report __P((struct ip_fw *f, struct ip *ip, - struct ifnet *rif, struct ifnet *oif)); - -#ifdef IPFIREWALL_MODULE -static ip_fw_chk_t *old_chk_ptr; -static ip_fw_ctl_t *old_ctl_ptr; -#endif - -static int ip_fw_chk __P((struct ip **pip, int hlen, - struct ifnet *oif, int ignport, struct mbuf **m)); -static int ip_fw_ctl __P((int stage, struct mbuf **mm)); - -static char err_prefix[] = "ip_fw_ctl:"; - -/* - * Returns 1 if the port is matched by the vector, 0 otherwise - */ -static inline int -port_match(u_short *portptr, int nports, u_short port, int range_flag) -{ - if (!nports) - return 1; - if (range_flag) { - if (portptr[0] <= port && port <= portptr[1]) { - return 1; - } - nports -= 2; - portptr += 2; - } - while (nports-- > 0) { - if (*portptr++ == port) { - return 1; - } - } - return 0; -} - -static int -tcpflg_match(struct tcphdr *tcp, struct ip_fw *f) -{ - u_char flg_set, flg_clr; - - if ((f->fw_tcpf & IP_FW_TCPF_ESTAB) && - (tcp->th_flags & (IP_FW_TCPF_RST | IP_FW_TCPF_ACK))) - return 1; - - flg_set = tcp->th_flags & f->fw_tcpf; - flg_clr = tcp->th_flags & f->fw_tcpnf; - - if (flg_set != f->fw_tcpf) - return 0; - if (flg_clr) - return 0; - - return 1; -} - -static int -icmptype_match(struct icmp *icmp, struct ip_fw *f) -{ - int type; - - if (!(f->fw_flg & IP_FW_F_ICMPBIT)) - return(1); - - type = icmp->icmp_type; - - /* check for matching type in the bitmap */ - if (type < IP_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 && - (f->fw_icmptypes[type / (sizeof(unsigned) * 8)] & - (1U << (type % (8 * sizeof(unsigned)))))) - return(1); - - return(0); /* no match */ -} - -static int -ipopts_match(struct ip *ip, struct ip_fw *f) -{ - register u_char *cp; - int opt, optlen, cnt; - u_char opts, nopts, nopts_sve; - - cp = (u_char *)(ip + 1); - cnt = (ip->ip_hl << 2) - sizeof (struct ip); - opts = f->fw_ipopt; - nopts = nopts_sve = f->fw_ipnopt; - - for (; cnt > 0; cnt -= optlen, cp += optlen) { - opt = cp[IPOPT_OPTVAL]; - if (opt == IPOPT_EOL) - break; - if (opt == IPOPT_NOP) - optlen = 1; - else { - optlen = cp[IPOPT_OLEN]; - if (optlen <= 0 || optlen > cnt) { - return 0; /*XXX*/ - } - } - switch (opt) { - - default: - break; - - case IPOPT_LSRR: - opts &= ~IP_FW_IPOPT_LSRR; - nopts &= ~IP_FW_IPOPT_LSRR; - break; - - case IPOPT_SSRR: - opts &= ~IP_FW_IPOPT_SSRR; - nopts &= ~IP_FW_IPOPT_SSRR; - break; - - case IPOPT_RR: - opts &= ~IP_FW_IPOPT_RR; - nopts &= ~IP_FW_IPOPT_RR; - break; - case IPOPT_TS: - opts &= ~IP_FW_IPOPT_TS; - nopts &= ~IP_FW_IPOPT_TS; - break; - } - if (opts == nopts) - break; - } - if (opts == 0 && nopts == nopts_sve) - return 1; - else - return 0; -} - -static inline int -iface_match(struct ifnet *ifp, union ip_fw_if *ifu, int byname) -{ - /* Check by name or by IP address */ - if (byname) { - /* Check unit number (-1 is wildcard) */ - if (ifu->fu_via_if.unit != -1 - && ifp->if_unit != ifu->fu_via_if.unit) - return(0); - /* Check name */ - if (strncmp(ifp->if_name, ifu->fu_via_if.name, FW_IFNLEN)) - return(0); - return(1); - } else if (ifu->fu_via_ip.s_addr != 0) { /* Zero == wildcard */ - struct ifaddr *ia; - - for (ia = ifp->if_addrlist; ia; ia = ia->ifa_next) { - if (ia->ifa_addr == NULL) - continue; - if (ia->ifa_addr->sa_family != AF_INET) - continue; - if (ifu->fu_via_ip.s_addr != ((struct sockaddr_in *) - (ia->ifa_addr))->sin_addr.s_addr) - continue; - return(1); - } - return(0); - } - return(1); -} - -static void -ipfw_report(struct ip_fw *f, struct ip *ip, - struct ifnet *rif, struct ifnet *oif) -{ - static int counter; - struct tcphdr *const tcp = (struct tcphdr *) ((u_long *) ip+ ip->ip_hl); - struct udphdr *const udp = (struct udphdr *) ((u_long *) ip+ ip->ip_hl); - struct icmp *const icmp = (struct icmp *) ((u_long *) ip + ip->ip_hl); - int count; - - count = f ? f->fw_pcnt : ++counter; - if (fw_verbose_limit != 0 && count > fw_verbose_limit) - return; - - /* Print command name */ - printf("ipfw: %d ", f ? f->fw_number : -1); - if (!f) - printf("Refuse"); - else - switch (f->fw_flg & IP_FW_F_COMMAND) { - case IP_FW_F_DENY: - printf("Deny"); - break; - case IP_FW_F_REJECT: - if (f->fw_reject_code == IP_FW_REJECT_RST) - printf("Reset"); - else - printf("Unreach"); - break; - case IP_FW_F_ACCEPT: - printf("Accept"); - break; - case IP_FW_F_COUNT: - printf("Count"); - break; - case IP_FW_F_DIVERT: - printf("Divert %d", f->fw_divert_port); - break; - case IP_FW_F_TEE: - printf("Tee %d", f->fw_divert_port); - break; - case IP_FW_F_SKIPTO: - printf("SkipTo %d", f->fw_skipto_rule); - break; - default: - printf("UNKNOWN"); - break; - } - printf(" "); - - switch (ip->ip_p) { - case IPPROTO_TCP: - printf("TCP "); - print_ip(ip->ip_src); - if ((ip->ip_off & IP_OFFMASK) == 0) - printf(":%d ", ntohs(tcp->th_sport)); - else - printf(" "); - print_ip(ip->ip_dst); - if ((ip->ip_off & IP_OFFMASK) == 0) - printf(":%d", ntohs(tcp->th_dport)); - break; - case IPPROTO_UDP: - printf("UDP "); - print_ip(ip->ip_src); - if ((ip->ip_off & IP_OFFMASK) == 0) - printf(":%d ", ntohs(udp->uh_sport)); - else - printf(" "); - print_ip(ip->ip_dst); - if ((ip->ip_off & IP_OFFMASK) == 0) - printf(":%d", ntohs(udp->uh_dport)); - break; - case IPPROTO_ICMP: - printf("ICMP:%u.%u ", icmp->icmp_type, icmp->icmp_code); - print_ip(ip->ip_src); - printf(" "); - print_ip(ip->ip_dst); - break; - default: - printf("P:%d ", ip->ip_p); - print_ip(ip->ip_src); - printf(" "); - print_ip(ip->ip_dst); - break; - } - if (oif) - printf(" out via %s%d", oif->if_name, oif->if_unit); - else if (rif) - printf(" in via %s%d", rif->if_name, rif->if_unit); - if ((ip->ip_off & IP_OFFMASK)) - printf(" Fragment = %d",ip->ip_off & IP_OFFMASK); - printf("\n"); - if (fw_verbose_limit != 0 && count == fw_verbose_limit) - printf("ipfw: limit reached on rule #%d\n", - f ? f->fw_number : -1); -} - -/* - * Parameters: - * - * ip Pointer to packet header (struct ip *) - * hlen Packet header length - * oif Outgoing interface, or NULL if packet is incoming - * ignport Ignore all divert/tee rules to this port (if non-zero) - * *m The packet; we set to NULL when/if we nuke it. - * - * Return value: - * - * 0 The packet is to be accepted and routed normally OR - * the packet was denied/rejected and has been dropped; - * in the latter case, *m is equal to NULL upon return. - * port Divert the packet to port. - */ - -static int -ip_fw_chk(struct ip **pip, int hlen, - struct ifnet *oif, int ignport, struct mbuf **m) -{ - struct ip_fw_chain *chain; - struct ip_fw *rule = NULL; - struct ip *ip = *pip; - struct ifnet *const rif = (*m)->m_pkthdr.rcvif; - u_short offset = (ip->ip_off & IP_OFFMASK); - u_short src_port, dst_port; - - /* - * Go down the chain, looking for enlightment - */ - for (chain=ip_fw_chain.lh_first; chain; chain = chain->chain.le_next) { - register struct ip_fw *const f = chain->rule; - - /* Check direction inbound */ - if (!oif && !(f->fw_flg & IP_FW_F_IN)) - continue; - - /* Check direction outbound */ - if (oif && !(f->fw_flg & IP_FW_F_OUT)) - continue; - - /* Fragments */ - if ((f->fw_flg & IP_FW_F_FRAG) && !(ip->ip_off & IP_OFFMASK)) - continue; - - /* If src-addr doesn't match, not this rule. */ - if (((f->fw_flg & IP_FW_F_INVSRC) != 0) ^ ((ip->ip_src.s_addr - & f->fw_smsk.s_addr) != f->fw_src.s_addr)) - continue; - - /* If dest-addr doesn't match, not this rule. */ - if (((f->fw_flg & IP_FW_F_INVDST) != 0) ^ ((ip->ip_dst.s_addr - & f->fw_dmsk.s_addr) != f->fw_dst.s_addr)) - continue; - - /* Interface check */ - if ((f->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) { - struct ifnet *const iface = oif ? oif : rif; - - /* Backwards compatibility hack for "via" */ - if (!iface || !iface_match(iface, - &f->fw_in_if, f->fw_flg & IP_FW_F_OIFNAME)) - continue; - } else { - /* Check receive interface */ - if ((f->fw_flg & IP_FW_F_IIFACE) - && (!rif || !iface_match(rif, - &f->fw_in_if, f->fw_flg & IP_FW_F_IIFNAME))) - continue; - /* Check outgoing interface */ - if ((f->fw_flg & IP_FW_F_OIFACE) - && (!oif || !iface_match(oif, - &f->fw_out_if, f->fw_flg & IP_FW_F_OIFNAME))) - continue; - } - - /* Check IP options */ - if (f->fw_ipopt != f->fw_ipnopt && !ipopts_match(ip, f)) - continue; - - /* Check protocol; if wildcard, match */ - if (f->fw_prot == IPPROTO_IP) - goto got_match; - - /* If different, don't match */ - if (ip->ip_p != f->fw_prot) - continue; - -#define PULLUP_TO(len) do { \ - if ((*m)->m_len < (len) \ - && (*m = m_pullup(*m, (len))) == 0) { \ - goto bogusfrag; \ - } \ - *pip = ip = mtod(*m, struct ip *); \ - offset = (ip->ip_off & IP_OFFMASK); \ - } while (0) - - /* Protocol specific checks */ - switch (ip->ip_p) { - case IPPROTO_TCP: - { - struct tcphdr *tcp; - - if (offset == 1) /* cf. RFC 1858 */ - goto bogusfrag; - if (offset != 0) { - /* - * TCP flags and ports aren't available in this - * packet -- if this rule specified either one, - * we consider the rule a non-match. - */ - if (f->fw_nports != 0 || - f->fw_tcpf != f->fw_tcpnf) - continue; - - break; - } - PULLUP_TO(hlen + 14); - tcp = (struct tcphdr *) ((u_long *)ip + ip->ip_hl); - if (f->fw_tcpf != f->fw_tcpnf && !tcpflg_match(tcp, f)) - continue; - src_port = ntohs(tcp->th_sport); - dst_port = ntohs(tcp->th_dport); - goto check_ports; - } - - case IPPROTO_UDP: - { - struct udphdr *udp; - - if (offset != 0) { - /* - * Port specification is unavailable -- if this - * rule specifies a port, we consider the rule - * a non-match. - */ - if (f->fw_nports != 0) - continue; - - break; - } - PULLUP_TO(hlen + 4); - udp = (struct udphdr *) ((u_long *)ip + ip->ip_hl); - src_port = ntohs(udp->uh_sport); - dst_port = ntohs(udp->uh_dport); -check_ports: - if (!port_match(&f->fw_pts[0], - IP_FW_GETNSRCP(f), src_port, - f->fw_flg & IP_FW_F_SRNG)) - continue; - if (!port_match(&f->fw_pts[IP_FW_GETNSRCP(f)], - IP_FW_GETNDSTP(f), dst_port, - f->fw_flg & IP_FW_F_DRNG)) - continue; - break; - } - - case IPPROTO_ICMP: - { - struct icmp *icmp; - - if (offset != 0) /* Type isn't valid */ - break; - PULLUP_TO(hlen + 2); - icmp = (struct icmp *) ((u_long *)ip + ip->ip_hl); - if (!icmptype_match(icmp, f)) - continue; - break; - } -#undef PULLUP_TO - -bogusfrag: - if (fw_verbose) - ipfw_report(NULL, ip, rif, oif); - goto dropit; - } - -got_match: - /* Ignore divert/tee rule if socket port is "ignport" */ - switch (f->fw_flg & IP_FW_F_COMMAND) { - case IP_FW_F_DIVERT: - case IP_FW_F_TEE: - if (f->fw_divert_port == ignport) - continue; /* ignore this rule */ - break; - } - - /* Update statistics */ - f->fw_pcnt += 1; - f->fw_bcnt += ip->ip_len; - f->timestamp = rtems_bsdnet_seconds_since_boot(); - - /* Log to console if desired */ - if ((f->fw_flg & IP_FW_F_PRN) && fw_verbose) - ipfw_report(f, ip, rif, oif); - - /* Take appropriate action */ - switch (f->fw_flg & IP_FW_F_COMMAND) { - case IP_FW_F_ACCEPT: - return(0); - case IP_FW_F_COUNT: - continue; - case IP_FW_F_DIVERT: - return(f->fw_divert_port); - case IP_FW_F_TEE: - /* - * XXX someday tee packet here, but beware that you - * can't use m_copym() or m_copypacket() because - * the divert input routine modifies the mbuf - * (and these routines only increment reference - * counts in the case of mbuf clusters), so need - * to write custom routine. - */ - continue; - case IP_FW_F_SKIPTO: -#ifdef DIAGNOSTIC - while (chain->chain.le_next - && chain->chain.le_next->rule->fw_number - < f->fw_skipto_rule) -#else - while (chain->chain.le_next->rule->fw_number - < f->fw_skipto_rule) -#endif - chain = chain->chain.le_next; - continue; - } - - /* Deny/reject this packet using this rule */ - rule = f; - break; - } - -#ifdef DIAGNOSTIC - /* Rule 65535 should always be there and should always match */ - if (!chain) - panic("ip_fw: chain"); -#endif - - /* - * At this point, we're going to drop the packet. - * Send a reject notice if all of the following are true: - * - * - The packet matched a reject rule - * - The packet is not an ICMP packet - * - The packet is not a multicast or broadcast packet - */ - if ((rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_REJECT - && ip->ip_p != IPPROTO_ICMP - && !((*m)->m_flags & (M_BCAST|M_MCAST)) - && !IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { - switch (rule->fw_reject_code) { - case IP_FW_REJECT_RST: - { - struct tcphdr *const tcp = - (struct tcphdr *) ((u_long *)ip + ip->ip_hl); - struct tcpiphdr ti, *const tip = (struct tcpiphdr *) ip; - - if (offset != 0 || (tcp->th_flags & TH_RST)) - break; - ti.ti_i = *((struct ipovly *) ip); - ti.ti_t = *tcp; - bcopy(&ti, ip, sizeof(ti)); - NTOHL(tip->ti_seq); - NTOHL(tip->ti_ack); - tip->ti_len = ip->ip_len - hlen - (tip->ti_off << 2); - if (tcp->th_flags & TH_ACK) { - tcp_respond(NULL, tip, *m, - (tcp_seq)0, ntohl(tcp->th_ack), TH_RST); - } else { - if (tcp->th_flags & TH_SYN) - tip->ti_len++; - tcp_respond(NULL, tip, *m, tip->ti_seq - + tip->ti_len, (tcp_seq)0, TH_RST|TH_ACK); - } - *m = NULL; - break; - } - default: /* Send an ICMP unreachable using code */ - icmp_error(*m, ICMP_UNREACH, - rule->fw_reject_code, 0L, 0); - *m = NULL; - break; - } - } - -dropit: - /* - * Finally, drop the packet. - */ - if (*m) { - m_freem(*m); - *m = NULL; - } - return(0); -} - -static int -add_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl) -{ - struct ip_fw *ftmp = 0; - struct ip_fw_chain *fwc = 0, *fcp, *fcpl = 0; - u_short nbr = 0; - int s; - - fwc = malloc(sizeof *fwc, M_IPFW, M_DONTWAIT); - ftmp = malloc(sizeof *ftmp, M_IPFW, M_DONTWAIT); - if (!fwc || !ftmp) { - dprintf(("%s malloc said no\n", err_prefix)); - if (fwc) free(fwc, M_IPFW); - if (ftmp) free(ftmp, M_IPFW); - return (ENOSPC); - } - - bcopy(frwl, ftmp, sizeof(struct ip_fw)); - ftmp->fw_in_if.fu_via_if.name[FW_IFNLEN - 1] = '\0'; - ftmp->fw_pcnt = 0L; - ftmp->fw_bcnt = 0L; - fwc->rule = ftmp; - - s = splnet(); - - if (!chainptr->lh_first) { - LIST_INSERT_HEAD(chainptr, fwc, chain); - splx(s); - return(0); - } else if (ftmp->fw_number == (u_short)-1) { - if (fwc) free(fwc, M_IPFW); - if (ftmp) free(ftmp, M_IPFW); - splx(s); - dprintf(("%s bad rule number\n", err_prefix)); - return (EINVAL); - } - - /* If entry number is 0, find highest numbered rule and add 100 */ - if (ftmp->fw_number == 0) { - for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) { - if (fcp->rule->fw_number != (u_short)-1) - nbr = fcp->rule->fw_number; - else - break; - } - if (nbr < (u_short)-1 - 100) - nbr += 100; - ftmp->fw_number = nbr; - } - - /* Got a valid number; now insert it, keeping the list ordered */ - for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) { - if (fcp->rule->fw_number > ftmp->fw_number) { - if (fcpl) { - LIST_INSERT_AFTER(fcpl, fwc, chain); - } else { - LIST_INSERT_HEAD(chainptr, fwc, chain); - } - break; - } else { - fcpl = fcp; - } - } - - splx(s); - return (0); -} - -static int -del_entry(struct ip_fw_head *chainptr, u_short number) -{ - struct ip_fw_chain *fcp; - int s; - - s = splnet(); - - fcp = chainptr->lh_first; - if (number != (u_short)-1) { - for (; fcp; fcp = fcp->chain.le_next) { - if (fcp->rule->fw_number == number) { - LIST_REMOVE(fcp, chain); - splx(s); - free(fcp->rule, M_IPFW); - free(fcp, M_IPFW); - return 0; - } - } - } - - splx(s); - return (EINVAL); -} - -static int -zero_entry(struct mbuf *m) -{ - struct ip_fw *frwl; - struct ip_fw_chain *fcp; - int s; - - if (m) { - if (m->m_len != sizeof(struct ip_fw)) - return(EINVAL); - frwl = mtod(m, struct ip_fw *); - } - else - frwl = NULL; - - /* - * It's possible to insert multiple chain entries with the - * same number, so we don't stop after finding the first - * match if zeroing a specific entry. - */ - s = splnet(); - for (fcp = ip_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next) - if (!frwl || frwl->fw_number == fcp->rule->fw_number) { - fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0; - fcp->rule->timestamp = 0; - } - splx(s); - - if (fw_verbose) { - if (frwl) - printf("ipfw: Entry %d cleared.\n", frwl->fw_number); - else - printf("ipfw: Accounting cleared.\n"); - } - - return(0); -} - -static struct ip_fw * -check_ipfw_mbuf(struct mbuf *m) -{ - /* Check length */ - if (m->m_len != sizeof(struct ip_fw)) { - dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len, - (int)sizeof(struct ip_fw))); - return (NULL); - } - return(check_ipfw_struct(mtod(m, struct ip_fw *))); -} - -static struct ip_fw * -check_ipfw_struct(struct ip_fw *frwl) -{ - /* Check for invalid flag bits */ - if ((frwl->fw_flg & ~IP_FW_F_MASK) != 0) { - dprintf(("%s undefined flag bits set (flags=%x)\n", - err_prefix, frwl->fw_flg)); - return (NULL); - } - /* Must apply to incoming or outgoing (or both) */ - if (!(frwl->fw_flg & (IP_FW_F_IN | IP_FW_F_OUT))) { - dprintf(("%s neither in nor out\n", err_prefix)); - return (NULL); - } - /* Empty interface name is no good */ - if (((frwl->fw_flg & IP_FW_F_IIFNAME) - && !*frwl->fw_in_if.fu_via_if.name) - || ((frwl->fw_flg & IP_FW_F_OIFNAME) - && !*frwl->fw_out_if.fu_via_if.name)) { - dprintf(("%s empty interface name\n", err_prefix)); - return (NULL); - } - /* Sanity check interface matching */ - if ((frwl->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) { - ; /* allow "via" backwards compatibility */ - } else if ((frwl->fw_flg & IP_FW_F_IN) - && (frwl->fw_flg & IP_FW_F_OIFACE)) { - dprintf(("%s outgoing interface check on incoming\n", - err_prefix)); - return (NULL); - } - /* Sanity check port ranges */ - if ((frwl->fw_flg & IP_FW_F_SRNG) && IP_FW_GETNSRCP(frwl) < 2) { - dprintf(("%s src range set but n_src_p=%d\n", - err_prefix, IP_FW_GETNSRCP(frwl))); - return (NULL); - } - if ((frwl->fw_flg & IP_FW_F_DRNG) && IP_FW_GETNDSTP(frwl) < 2) { - dprintf(("%s dst range set but n_dst_p=%d\n", - err_prefix, IP_FW_GETNDSTP(frwl))); - return (NULL); - } - if (IP_FW_GETNSRCP(frwl) + IP_FW_GETNDSTP(frwl) > IP_FW_MAX_PORTS) { - dprintf(("%s too many ports (%d+%d)\n", - err_prefix, IP_FW_GETNSRCP(frwl), IP_FW_GETNDSTP(frwl))); - return (NULL); - } - /* - * Protocols other than TCP/UDP don't use port range - */ - if ((frwl->fw_prot != IPPROTO_TCP) && - (frwl->fw_prot != IPPROTO_UDP) && - (IP_FW_GETNSRCP(frwl) || IP_FW_GETNDSTP(frwl))) { - dprintf(("%s port(s) specified for non TCP/UDP rule\n", - err_prefix)); - return(NULL); - } - - /* - * Rather than modify the entry to make such entries work, - * we reject this rule and require user level utilities - * to enforce whatever policy they deem appropriate. - */ - if ((frwl->fw_src.s_addr & (~frwl->fw_smsk.s_addr)) || - (frwl->fw_dst.s_addr & (~frwl->fw_dmsk.s_addr))) { - dprintf(("%s rule never matches\n", err_prefix)); - return(NULL); - } - - if ((frwl->fw_flg & IP_FW_F_FRAG) && - (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) { - if (frwl->fw_nports) { - dprintf(("%s cannot mix 'frag' and ports\n", err_prefix)); - return(NULL); - } - if (frwl->fw_prot == IPPROTO_TCP && - frwl->fw_tcpf != frwl->fw_tcpnf) { - dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix)); - return(NULL); - } - } - - /* Check command specific stuff */ - switch (frwl->fw_flg & IP_FW_F_COMMAND) - { - case IP_FW_F_REJECT: - if (frwl->fw_reject_code >= 0x100 - && !(frwl->fw_prot == IPPROTO_TCP - && frwl->fw_reject_code == IP_FW_REJECT_RST)) { - dprintf(("%s unknown reject code\n", err_prefix)); - return(NULL); - } - break; - case IP_FW_F_DIVERT: /* Diverting to port zero is invalid */ - case IP_FW_F_TEE: - if (frwl->fw_divert_port == 0) { - dprintf(("%s can't divert to port 0\n", err_prefix)); - return (NULL); - } - break; - case IP_FW_F_DENY: - case IP_FW_F_ACCEPT: - case IP_FW_F_COUNT: - case IP_FW_F_SKIPTO: - break; - default: - dprintf(("%s invalid command\n", err_prefix)); - return(NULL); - } - - return frwl; -} - -static int -ip_fw_ctl(int stage, struct mbuf **mm) -{ - int error; - struct mbuf *m; - - if (stage == IP_FW_GET) { - struct ip_fw_chain *fcp = ip_fw_chain.lh_first; - *mm = m = m_get(M_WAIT, MT_SOOPTS); - for (; fcp; fcp = fcp->chain.le_next) { - memcpy(m->m_data, fcp->rule, sizeof *(fcp->rule)); - m->m_len = sizeof *(fcp->rule); - m->m_next = m_get(M_WAIT, MT_SOOPTS); - m = m->m_next; - m->m_len = 0; - } - return (0); - } - m = *mm; - /* only allow get calls if secure mode > 2 */ - if (securelevel > 2) { - if (m) (void)m_free(m); - return(EPERM); - } - if (stage == IP_FW_FLUSH) { - while (ip_fw_chain.lh_first != NULL && - ip_fw_chain.lh_first->rule->fw_number != (u_short)-1) { - struct ip_fw_chain *fcp = ip_fw_chain.lh_first; - int s = splnet(); - LIST_REMOVE(ip_fw_chain.lh_first, chain); - splx(s); - free(fcp->rule, M_IPFW); - free(fcp, M_IPFW); - } - if (m) (void)m_free(m); - return (0); - } - if (stage == IP_FW_ZERO) { - error = zero_entry(m); - if (m) (void)m_free(m); - return (error); - } - if (m == NULL) { - printf("%s NULL mbuf ptr\n", err_prefix); - return (EINVAL); - } - - if (stage == IP_FW_ADD) { - struct ip_fw *frwl = check_ipfw_mbuf(m); - - if (!frwl) - error = EINVAL; - else - error = add_entry(&ip_fw_chain, frwl); - if (m) (void)m_free(m); - return error; - } - if (stage == IP_FW_DEL) { - if (m->m_len != sizeof(struct ip_fw)) { - dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len, - (int)sizeof(struct ip_fw))); - error = EINVAL; - } else if (mtod(m, struct ip_fw *)->fw_number == (u_short)-1) { - dprintf(("%s can't delete rule 65535\n", err_prefix)); - error = EINVAL; - } else - error = del_entry(&ip_fw_chain, - mtod(m, struct ip_fw *)->fw_number); - if (m) (void)m_free(m); - return error; - } - - dprintf(("%s unknown request %d\n", err_prefix, stage)); - if (m) (void)m_free(m); - return (EINVAL); -} - -void -ip_fw_init(void) -{ - struct ip_fw default_rule; - - ip_fw_chk_ptr = ip_fw_chk; - ip_fw_ctl_ptr = ip_fw_ctl; - LIST_INIT(&ip_fw_chain); - - bzero(&default_rule, sizeof default_rule); - default_rule.fw_prot = IPPROTO_IP; - default_rule.fw_number = (u_short)-1; -#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT - default_rule.fw_flg |= IP_FW_F_ACCEPT; -#else - default_rule.fw_flg |= IP_FW_F_DENY; -#endif - default_rule.fw_flg |= IP_FW_F_IN | IP_FW_F_OUT; - if (check_ipfw_struct(&default_rule) == NULL || - add_entry(&ip_fw_chain, &default_rule)) - panic(__FUNCTION__); - - printf("IP packet filtering initialized, " -#ifdef IPDIVERT - "divert enabled, "); -#else - "divert disabled, "); -#endif -#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT - printf("default to accept, "); -#endif -#ifndef IPFIREWALL_VERBOSE - printf("logging disabled\n"); -#else - if (fw_verbose_limit == 0) - printf("unlimited logging\n"); - else - printf("logging limited to %d packets/entry\n", - fw_verbose_limit); -#endif -} - -#ifdef IPFIREWALL_MODULE - -#include <sys/exec.h> -#include <sys/sysent.h> -#include <sys/lkm.h> - -MOD_MISC(ipfw); - -static int -ipfw_load(struct lkm_table *lkmtp, int cmd) -{ - int s=splnet(); - - old_chk_ptr = ip_fw_chk_ptr; - old_ctl_ptr = ip_fw_ctl_ptr; - - ip_fw_init(); - splx(s); - return 0; -} - -static int -ipfw_unload(struct lkm_table *lkmtp, int cmd) -{ - int s=splnet(); - - ip_fw_chk_ptr = old_chk_ptr; - ip_fw_ctl_ptr = old_ctl_ptr; - - while (ip_fw_chain.lh_first != NULL) { - struct ip_fw_chain *fcp = ip_fw_chain.lh_first; - LIST_REMOVE(ip_fw_chain.lh_first, chain); - free(fcp->rule, M_IPFW); - free(fcp, M_IPFW); - } - - splx(s); - printf("IP firewall unloaded\n"); - return 0; -} - -int -ipfw_mod(struct lkm_table *lkmtp, int cmd, int ver) -{ - DISPATCH(lkmtp, cmd, ver, ipfw_load, ipfw_unload, lkm_nullcmd); -} -#endif |