static __inline void unlink_dyn_rule_print(struct ipfw_flow_id *id) { struct in_addr da; #ifdef INET6 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; #else char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN]; #endif #ifdef INET6 if (IS_IP6_FLOW_ID(id)) { ip6_sprintf(src, &id->src_ip6); ip6_sprintf(dst, &id->dst_ip6); } else #endif { da.s_addr = htonl(id->src_ip); inet_ntoa_r(da, src); da.s_addr = htonl(id->dst_ip); inet_ntoa_r(da, dst); } printf("ipfw: unlink entry %s %d -> %s %d, %d left\n", src, id->src_port, dst, id->dst_port, V_dyn_count - 1); }
/** * Print customizable flow id description via log(9) facility. */ static void print_dyn_rule_flags(struct ipfw_flow_id *id, int dyn_type, int log_flags, char *prefix, char *postfix) { struct in_addr da; #ifdef INET6 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; #else char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN]; #endif #ifdef INET6 if (IS_IP6_FLOW_ID(id)) { ip6_sprintf(src, &id->src_ip6); ip6_sprintf(dst, &id->dst_ip6); } else #endif { da.s_addr = htonl(id->src_ip); inet_ntop(AF_INET, &da, src, sizeof(src)); da.s_addr = htonl(id->dst_ip); inet_ntop(AF_INET, &da, dst, sizeof(dst)); } log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n", prefix, dyn_type, src, id->src_port, dst, id->dst_port, DYN_COUNT, postfix); }
/* * IMPORTANT: the hash function for dynamic rules must be commutative * in source and destination (ip,port), because rules are bidirectional * and we want to find both in the same bucket. */ static __inline int hash_packet(struct ipfw_flow_id *id) { u_int32_t i; #ifdef INET6 if (IS_IP6_FLOW_ID(id)) i = hash_packet6(id); else #endif /* INET6 */ i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); i &= (V_curr_dyn_buckets - 1); return i; }
/** * Install state of type 'type' for a dynamic session. * The hash table contains two type of rules: * - regular rules (O_KEEP_STATE) * - rules for sessions with limited number of sess per user * (O_LIMIT). When they are created, the parent is * increased by 1, and decreased on delete. In this case, * the third parameter is the parent rule and not the chain. * - "parent" rules for the above (O_LIMIT_PARENT). */ static ipfw_dyn_rule * add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) { ipfw_dyn_rule *r; int i; IPFW_DYN_LOCK_ASSERT(); if (V_ipfw_dyn_v == NULL || (V_dyn_count == 0 && V_dyn_buckets != V_curr_dyn_buckets)) { realloc_dynamic_table(); if (V_ipfw_dyn_v == NULL) return NULL; /* failed ! */ } i = hash_packet(id); r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); if (r == NULL) { printf ("ipfw: sorry cannot allocate state\n"); return NULL; } /* increase refcount on parent, and set pointer */ if (dyn_type == O_LIMIT) { ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; if ( parent->dyn_type != O_LIMIT_PARENT) panic("invalid parent"); parent->count++; r->parent = parent; rule = parent->rule; } r->id = *id; r->expire = time_uptime + V_dyn_syn_lifetime; r->rule = rule; r->dyn_type = dyn_type; r->pcnt = r->bcnt = 0; r->count = 0; r->bucket = i; r->next = V_ipfw_dyn_v[i]; V_ipfw_dyn_v[i] = r; V_dyn_count++; DEB({ struct in_addr da; #ifdef INET6 char src[INET6_ADDRSTRLEN]; char dst[INET6_ADDRSTRLEN]; #else char src[INET_ADDRSTRLEN]; char dst[INET_ADDRSTRLEN]; #endif #ifdef INET6 if (IS_IP6_FLOW_ID(&(r->id))) { ip6_sprintf(src, &r->id.src_ip6); ip6_sprintf(dst, &r->id.dst_ip6); } else #endif { da.s_addr = htonl(r->id.src_ip); inet_ntoa_r(da, src); da.s_addr = htonl(r->id.dst_ip); inet_ntoa_r(da, dst); } printf("ipfw: add dyn entry ty %d %s %d -> %s %d, total %d\n", dyn_type, src, r->id.src_port, dst, r->id.dst_port, V_dyn_count); }) return r;
/* * Lookup a dynamic rule, locked version. */ static ipfw_dyn_rule * lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, struct tcphdr *tcp) { /* * Stateful ipfw extensions. * Lookup into dynamic session queue. */ #define MATCH_REVERSE 0 #define MATCH_FORWARD 1 #define MATCH_NONE 2 #define MATCH_UNKNOWN 3 int i, dir = MATCH_NONE; ipfw_dyn_rule *prev, *q = NULL; IPFW_DYN_LOCK_ASSERT(); if (V_ipfw_dyn_v == NULL) goto done; /* not found */ i = hash_packet(pkt); for (prev = NULL, q = V_ipfw_dyn_v[i]; q != NULL;) { if (q->dyn_type == O_LIMIT_PARENT && q->count) goto next; if (TIME_LEQ(q->expire, time_uptime)) { /* expire entry */ UNLINK_DYN_RULE(prev, V_ipfw_dyn_v[i], q); continue; } if (pkt->proto != q->id.proto || q->dyn_type == O_LIMIT_PARENT) goto next; if (IS_IP6_FLOW_ID(pkt)) { if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.src_ip6) && IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.dst_ip6) && pkt->src_port == q->id.src_port && pkt->dst_port == q->id.dst_port) { dir = MATCH_FORWARD; break; } if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.dst_ip6) && IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.src_ip6) && pkt->src_port == q->id.dst_port && pkt->dst_port == q->id.src_port) { dir = MATCH_REVERSE; break; } } else { if (pkt->src_ip == q->id.src_ip && pkt->dst_ip == q->id.dst_ip && pkt->src_port == q->id.src_port && pkt->dst_port == q->id.dst_port) { dir = MATCH_FORWARD; break; } if (pkt->src_ip == q->id.dst_ip && pkt->dst_ip == q->id.src_ip && pkt->src_port == q->id.dst_port && pkt->dst_port == q->id.src_port) { dir = MATCH_REVERSE; break; } } next: prev = q; q = q->next; } if (q == NULL) goto done; /* q = NULL, not found */ if (prev != NULL) { /* found and not in front */ prev->next = q->next; q->next = V_ipfw_dyn_v[i]; V_ipfw_dyn_v[i] = q; } if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ uint32_t ack; u_char flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST); #define BOTH_SYN (TH_SYN | (TH_SYN << 8)) #define BOTH_FIN (TH_FIN | (TH_FIN << 8)) #define TCP_FLAGS (TH_FLAGS | (TH_FLAGS << 8)) #define ACK_FWD 0x10000 /* fwd ack seen */ #define ACK_REV 0x20000 /* rev ack seen */ q->state |= (dir == MATCH_FORWARD) ? flags : (flags << 8); switch (q->state & TCP_FLAGS) { case TH_SYN: /* opening */ q->expire = time_uptime + V_dyn_syn_lifetime; break; case BOTH_SYN: /* move to established */ case BOTH_SYN | TH_FIN: /* one side tries to close */ case BOTH_SYN | (TH_FIN << 8): #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) if (tcp == NULL) break; ack = ntohl(tcp->th_ack); if (dir == MATCH_FORWARD) { if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) { q->ack_fwd = ack; q->state |= ACK_FWD; } } else { if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) { q->ack_rev = ack; q->state |= ACK_REV; } } if ((q->state & (ACK_FWD | ACK_REV)) == (ACK_FWD | ACK_REV)) { q->expire = time_uptime + V_dyn_ack_lifetime; q->state &= ~(ACK_FWD | ACK_REV); } break; case BOTH_SYN | BOTH_FIN: /* both sides closed */ if (V_dyn_fin_lifetime >= V_dyn_keepalive_period) V_dyn_fin_lifetime = V_dyn_keepalive_period - 1; q->expire = time_uptime + V_dyn_fin_lifetime; break; default: #if 0 /* * reset or some invalid combination, but can also * occur if we use keep-state the wrong way. */ if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) printf("invalid state: 0x%x\n", q->state); #endif if (V_dyn_rst_lifetime >= V_dyn_keepalive_period) V_dyn_rst_lifetime = V_dyn_keepalive_period - 1; q->expire = time_uptime + V_dyn_rst_lifetime; break; } } else if (pkt->proto == IPPROTO_UDP) { q->expire = time_uptime + V_dyn_udp_lifetime; } else { /* other protocols */ q->expire = time_uptime + V_dyn_short_lifetime; } done: if (match_direction != NULL) *match_direction = dir; return (q); }
/* * We enter here when we have a rule with O_LOG. * XXX this function alone takes about 2Kbytes of code! */ void ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, struct mbuf *m, struct ifnet *oif, u_short offset, uint32_t tablearg, struct ip *ip) { char *action; int limit_reached = 0; char action2[92], proto[128], fragment[32]; if (V_fw_verbose == 0) { #ifndef WITHOUT_BPF LOGIF_RLOCK(); if (log_if == NULL || log_if->if_bpf == NULL) { LOGIF_RUNLOCK(); return; } if (args->eh) /* layer2, use orig hdr */ BPF_MTAP2(log_if, args->eh, ETHER_HDR_LEN, m); else /* Add fake header. Later we will store * more info in the header. */ BPF_MTAP2(log_if, "DDDDDDSSSSSS\x08\x00", ETHER_HDR_LEN, m); LOGIF_RUNLOCK(); #endif /* !WITHOUT_BPF */ return; } /* the old 'log' function */ fragment[0] = '\0'; proto[0] = '\0'; if (f == NULL) { /* bogus pkt */ if (V_verbose_limit != 0 && V_norule_counter >= V_verbose_limit) return; V_norule_counter++; if (V_norule_counter == V_verbose_limit) limit_reached = V_verbose_limit; action = "Refuse"; } else { /* O_LOG is the first action, find the real one */ ipfw_insn *cmd = ACTION_PTR(f); ipfw_insn_log *l = (ipfw_insn_log *)cmd; if (l->max_log != 0 && l->log_left == 0) return; l->log_left--; if (l->log_left == 0) limit_reached = l->max_log; cmd += F_LEN(cmd); /* point to first action */ if (cmd->opcode == O_ALTQ) { ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; snprintf(SNPARGS(action2, 0), "Altq %d", altq->qid); cmd += F_LEN(cmd); } if (cmd->opcode == O_PROB) cmd += F_LEN(cmd); if (cmd->opcode == O_TAG) cmd += F_LEN(cmd); action = action2; switch (cmd->opcode) { case O_DENY: action = "Deny"; break; case O_REJECT: if (cmd->arg1==ICMP_REJECT_RST) action = "Reset"; else if (cmd->arg1==ICMP_UNREACH_HOST) action = "Reject"; else snprintf(SNPARGS(action2, 0), "Unreach %d", cmd->arg1); break; case O_UNREACH6: if (cmd->arg1==ICMP6_UNREACH_RST) action = "Reset"; else snprintf(SNPARGS(action2, 0), "Unreach %d", cmd->arg1); break; case O_ACCEPT: action = "Accept"; break; case O_COUNT: action = "Count"; break; case O_DIVERT: snprintf(SNPARGS(action2, 0), "Divert %d", cmd->arg1); break; case O_TEE: snprintf(SNPARGS(action2, 0), "Tee %d", cmd->arg1); break; case O_SETFIB: snprintf(SNPARGS(action2, 0), "SetFib %d", IP_FW_ARG_TABLEARG(cmd->arg1)); break; case O_SKIPTO: snprintf(SNPARGS(action2, 0), "SkipTo %d", IP_FW_ARG_TABLEARG(cmd->arg1)); break; case O_PIPE: snprintf(SNPARGS(action2, 0), "Pipe %d", IP_FW_ARG_TABLEARG(cmd->arg1)); break; case O_QUEUE: snprintf(SNPARGS(action2, 0), "Queue %d", IP_FW_ARG_TABLEARG(cmd->arg1)); break; case O_FORWARD_IP: { ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; int len; struct in_addr dummyaddr; if (sa->sa.sin_addr.s_addr == INADDR_ANY) dummyaddr.s_addr = htonl(tablearg); else dummyaddr.s_addr = sa->sa.sin_addr.s_addr; len = snprintf(SNPARGS(action2, 0), "Forward to %s", inet_ntoa(dummyaddr)); if (sa->sa.sin_port) snprintf(SNPARGS(action2, len), ":%d", sa->sa.sin_port); } break; #ifdef INET6 case O_FORWARD_IP6: { char buf[INET6_ADDRSTRLEN]; ipfw_insn_sa6 *sa = (ipfw_insn_sa6 *)cmd; int len; len = snprintf(SNPARGS(action2, 0), "Forward to [%s]", ip6_sprintf(buf, &sa->sa.sin6_addr)); if (sa->sa.sin6_port) snprintf(SNPARGS(action2, len), ":%u", sa->sa.sin6_port); } break; #endif case O_NETGRAPH: snprintf(SNPARGS(action2, 0), "Netgraph %d", cmd->arg1); break; case O_NGTEE: snprintf(SNPARGS(action2, 0), "Ngtee %d", cmd->arg1); break; case O_NAT: action = "Nat"; break; case O_REASS: action = "Reass"; break; case O_CALLRETURN: if (cmd->len & F_NOT) action = "Return"; else snprintf(SNPARGS(action2, 0), "Call %d", cmd->arg1); break; default: action = "UNKNOWN"; break; } } if (hlen == 0) { /* non-ip */ snprintf(SNPARGS(proto, 0), "MAC"); } else { int len; #ifdef INET6 char src[INET6_ADDRSTRLEN + 2], dst[INET6_ADDRSTRLEN + 2]; #else char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN]; #endif struct icmphdr *icmp; struct tcphdr *tcp; struct udphdr *udp; #ifdef INET6 struct ip6_hdr *ip6 = NULL; struct icmp6_hdr *icmp6; u_short ip6f_mf; #endif src[0] = '\0'; dst[0] = '\0'; #ifdef INET6 ip6f_mf = offset & IP6F_MORE_FRAG; offset &= IP6F_OFF_MASK; if (IS_IP6_FLOW_ID(&(args->f_id))) { char ip6buf[INET6_ADDRSTRLEN]; snprintf(src, sizeof(src), "[%s]", ip6_sprintf(ip6buf, &args->f_id.src_ip6)); snprintf(dst, sizeof(dst), "[%s]", ip6_sprintf(ip6buf, &args->f_id.dst_ip6)); ip6 = (struct ip6_hdr *)ip; tcp = (struct tcphdr *)(((char *)ip) + hlen); udp = (struct udphdr *)(((char *)ip) + hlen); } else #endif { tcp = L3HDR(struct tcphdr, ip); udp = L3HDR(struct udphdr, ip); inet_ntop(AF_INET, &ip->ip_src, src, sizeof(src)); inet_ntop(AF_INET, &ip->ip_dst, dst, sizeof(dst)); } switch (args->f_id.proto) { case IPPROTO_TCP: len = snprintf(SNPARGS(proto, 0), "TCP %s", src); if (offset == 0) snprintf(SNPARGS(proto, len), ":%d %s:%d", ntohs(tcp->th_sport), dst, ntohs(tcp->th_dport)); else snprintf(SNPARGS(proto, len), " %s", dst); break; case IPPROTO_UDP: len = snprintf(SNPARGS(proto, 0), "UDP %s", src); if (offset == 0) snprintf(SNPARGS(proto, len), ":%d %s:%d", ntohs(udp->uh_sport), dst, ntohs(udp->uh_dport)); else snprintf(SNPARGS(proto, len), " %s", dst); break; case IPPROTO_ICMP: icmp = L3HDR(struct icmphdr, ip); if (offset == 0) len = snprintf(SNPARGS(proto, 0), "ICMP:%u.%u ", icmp->icmp_type, icmp->icmp_code); else len = snprintf(SNPARGS(proto, 0), "ICMP "); len += snprintf(SNPARGS(proto, len), "%s", src); snprintf(SNPARGS(proto, len), " %s", dst); break; #ifdef INET6 case IPPROTO_ICMPV6: icmp6 = (struct icmp6_hdr *)(((char *)ip) + hlen); if (offset == 0) len = snprintf(SNPARGS(proto, 0), "ICMPv6:%u.%u ", icmp6->icmp6_type, icmp6->icmp6_code); else len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); len += snprintf(SNPARGS(proto, len), "%s", src); snprintf(SNPARGS(proto, len), " %s", dst); break; #endif default: len = snprintf(SNPARGS(proto, 0), "P:%d %s", args->f_id.proto, src); snprintf(SNPARGS(proto, len), " %s", dst); break; } #ifdef INET6 if (IS_IP6_FLOW_ID(&(args->f_id))) { if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) snprintf(SNPARGS(fragment, 0), " (frag %08x:%d@%d%s)", args->f_id.extra, ntohs(ip6->ip6_plen) - hlen, ntohs(offset) << 3, ip6f_mf ? "+" : ""); } else #endif { int ipoff, iplen; ipoff = ntohs(ip->ip_off); iplen = ntohs(ip->ip_len); if (ipoff & (IP_MF | IP_OFFMASK)) snprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)", ntohs(ip->ip_id), iplen - (ip->ip_hl << 2), offset << 3, (ipoff & IP_MF) ? "+" : ""); } } #ifdef __FreeBSD__ if (oif || m->m_pkthdr.rcvif) log(LOG_SECURITY | LOG_INFO, "ipfw: %d %s %s %s via %s%s\n", f ? f->rulenum : -1, action, proto, oif ? "out" : "in", oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, fragment); else #endif log(LOG_SECURITY | LOG_INFO, "ipfw: %d %s %s [no if info]%s\n", f ? f->rulenum : -1, action, proto, fragment); if (limit_reached) log(LOG_SECURITY | LOG_NOTICE, "ipfw: limit %d reached on entry %d\n", limit_reached, f ? f->rulenum : -1); }
/* * Lookup a dynamic rule, locked version. */ static ipfw_dyn_rule * lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int i, int *match_direction, struct tcphdr *tcp) { /* * Stateful ipfw extensions. * Lookup into dynamic session queue. */ ipfw_dyn_rule *prev, *q = NULL; int dir; IPFW_BUCK_ASSERT(i); dir = MATCH_NONE; for (prev = NULL, q = V_ipfw_dyn_v[i].head; q; prev = q, q = q->next) { if (q->dyn_type == O_LIMIT_PARENT && q->count) continue; if (pkt->proto != q->id.proto || q->dyn_type == O_LIMIT_PARENT) continue; if (IS_IP6_FLOW_ID(pkt)) { if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.src_ip6) && IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.dst_ip6) && pkt->src_port == q->id.src_port && pkt->dst_port == q->id.dst_port) { dir = MATCH_FORWARD; break; } if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.dst_ip6) && IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.src_ip6) && pkt->src_port == q->id.dst_port && pkt->dst_port == q->id.src_port) { dir = MATCH_REVERSE; break; } } else { if (pkt->src_ip == q->id.src_ip && pkt->dst_ip == q->id.dst_ip && pkt->src_port == q->id.src_port && pkt->dst_port == q->id.dst_port) { dir = MATCH_FORWARD; break; } if (pkt->src_ip == q->id.dst_ip && pkt->dst_ip == q->id.src_ip && pkt->src_port == q->id.dst_port && pkt->dst_port == q->id.src_port) { dir = MATCH_REVERSE; break; } } } if (q == NULL) goto done; /* q = NULL, not found */ if (prev != NULL) { /* found and not in front */ prev->next = q->next; q->next = V_ipfw_dyn_v[i].head; V_ipfw_dyn_v[i].head = q; } /* update state according to flags */ dyn_update_proto_state(q, pkt, tcp, dir); done: if (match_direction != NULL) *match_direction = dir; return (q); }