1 files changed, 546 insertions, 2 deletions

diff --git a/sys/netinet/ip_fw2.c b/sys/netinet/ip_fw2.c
index 591e6ff530aa..070de18cb3bd 100644
--- a/sys/netinet/ip_fw2.c
+++ b/sys/netinet/ip_fw2.c
@@ -47,6 +47,7 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/condvar.h>
+#include <sys/eventhandler.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/kernel.h>
@@ -84,6 +85,8 @@
 #include <netinet/udp_var.h>
 #include <netinet/sctp.h>
 
+#include <netinet/libalias/alias.h>
+#include <netinet/libalias/alias_local.h>
 #include <netgraph/ng_ipfw.h>
 
 #include <altq/if_altq.h>
@@ -138,6 +141,7 @@ struct ip_fw_ugid {
 struct ip_fw_chain {
 	struct ip_fw	*rules;		/* list of rules */
 	struct ip_fw	*reap;		/* list of rules to reap */
+	LIST_HEAD(, cfg_nat) nat;       /* list of nat entries */
 	struct radix_node_head *tables[IPFW_TABLES_MAX];
 	struct rwlock	rwmtx;
 };
@@ -303,6 +307,7 @@ static struct sysctl_oid *ip6_fw_sysctl_tree;
 #endif /* INET6 */
 #endif /* SYSCTL_NODE */
 
+MODULE_DEPEND(ipfw, libalias, 1, 1, 1);
 static int fw_deny_unknown_exthdrs = 1;
 
 
@@ -861,6 +866,9 @@ ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args,
 			snprintf(SNPARGS(action2, 0), "Ngtee %d",
 				cmd->arg1);
 			break;
+		case O_NAT:
+			action = "Nat";
+ 			break;
 		default:
 			action = "UNKNOWN";
 			break;
@@ -2028,6 +2036,178 @@ check_uidgid(ipfw_insn_u32 *insn,
 	return match;
 }
 
+static eventhandler_tag ifaddr_event_tag;
+
+static void 
+ifaddr_change(void *arg __unused, struct ifnet *ifp) {
+	struct cfg_nat *ptr;
+	struct ifaddr *ifa;
+
+	IPFW_WLOCK(&layer3_chain);			
+	/* Check every nat entry... */
+	LIST_FOREACH(ptr, &layer3_chain.nat, _next) {
+		/* ...using nic 'ifp->if_xname' as dynamic alias address. */
+		if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) == 0) {
+			mtx_lock(&ifp->if_addr_mtx);
+			TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
+				if (ifa->ifa_addr == NULL)
+					continue;
+				if (ifa->ifa_addr->sa_family != AF_INET)
+					continue;
+				ptr->ip = ((struct sockaddr_in *) 
+				    (ifa->ifa_addr))->sin_addr;
+				LibAliasSetAddress(ptr->lib, ptr->ip);
+			}
+			mtx_unlock(&ifp->if_addr_mtx);
+		}
+	}
+	IPFW_WUNLOCK(&layer3_chain);	
+}
+
+static void
+flush_nat_ptrs(const int i) {
+	struct ip_fw *rule;
+
+	IPFW_WLOCK_ASSERT(&layer3_chain);
+	for (rule = layer3_chain.rules; rule; rule = rule->next) {
+		ipfw_insn_nat *cmd = (ipfw_insn_nat *)ACTION_PTR(rule);
+		if (cmd->o.opcode != O_NAT)
+			continue;
+		if (cmd->nat != NULL && cmd->nat->id == i)
+			cmd->nat = NULL;
+	}
+}
+
+static struct cfg_nat *
+lookup_nat(const int i) {
+	struct cfg_nat *ptr;
+
+	LIST_FOREACH(ptr, &layer3_chain.nat, _next)
+		if (ptr->id == i)
+			return(ptr);
+	return (NULL);
+}
+
+#define HOOK_NAT(b, p) do {                                     \
+	IPFW_WLOCK_ASSERT(&layer3_chain);                       \
+        LIST_INSERT_HEAD(b, p, _next);                          \
+} while (0)
+
+#define UNHOOK_NAT(p) do {                                      \
+	IPFW_WLOCK_ASSERT(&layer3_chain);                       \
+        LIST_REMOVE(p, _next);                                  \
+} while (0)
+
+#define HOOK_REDIR(b, p) do {                                   \
+        LIST_INSERT_HEAD(b, p, _next);                          \
+} while (0)
+
+#define HOOK_SPOOL(b, p) do {                                   \
+        LIST_INSERT_HEAD(b, p, _next);                          \
+} while (0)
+
+static void
+del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) {
+	struct cfg_redir *r, *tmp_r;
+	struct cfg_spool *s, *tmp_s;
+	int i, num;
+
+	LIST_FOREACH_SAFE(r, head, _next, tmp_r) {
+		num = 1; /* Number of alias_link to delete. */
+		switch (r->mode) {
+		case REDIR_PORT:
+			num = r->pport_cnt;
+			/* FALLTHROUGH */
+		case REDIR_ADDR:
+		case REDIR_PROTO:
+			/* Delete all libalias redirect entry. */
+			for (i = 0; i < num; i++)
+				LibAliasRedirectDelete(n->lib, r->alink[i]);
+			/* Del spool cfg if any. */
+			LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) {
+				LIST_REMOVE(s, _next);
+				free(s, M_IPFW);
+			}
+			free(r->alink, M_IPFW);
+			LIST_REMOVE(r, _next);
+			free(r, M_IPFW);
+			break;
+		default:
+			printf("unknown redirect mode: %u\n", r->mode);				
+			/* XXX - panic?!?!? */
+			break; 
+		}
+	}
+}
+
+static int
+add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) {
+	struct cfg_redir *r, *ser_r;
+	struct cfg_spool *s, *ser_s;
+	int cnt, off, i;
+	char *panic_err;
+
+	for (cnt = 0, off = 0; cnt < ptr->redir_cnt; cnt++) {
+		ser_r = (struct cfg_redir *)&buf[off];
+		r = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO);
+		memcpy(r, ser_r, SOF_REDIR);
+		LIST_INIT(&r->spool_chain);
+		off += SOF_REDIR;
+		r->alink = malloc(sizeof(struct alias_link *) * r->pport_cnt,
+		    M_IPFW, M_WAITOK | M_ZERO);
+		switch (r->mode) {
+		case REDIR_ADDR:
+			r->alink[0] = LibAliasRedirectAddr(ptr->lib, r->laddr,
+			    r->paddr);
+			break;
+		case REDIR_PORT:
+			for (i = 0 ; i < r->pport_cnt; i++) {
+				/* If remotePort is all ports, set it to 0. */
+				u_short remotePortCopy = r->rport + i;
+				if (r->rport_cnt == 1 && r->rport == 0)
+					remotePortCopy = 0;
+				r->alink[i] = LibAliasRedirectPort(ptr->lib, 
+				    r->laddr, htons(r->lport + i), r->raddr, 
+				    htons(remotePortCopy), r->paddr, 
+				    htons(r->pport + i), r->proto);
+				if (r->alink[i] == NULL) {
+					r->alink[0] = NULL;
+					break;
+				}
+			}
+			break;
+		case REDIR_PROTO:
+			r->alink[0] = LibAliasRedirectProto(ptr->lib ,r->laddr,
+			    r->raddr, r->paddr, r->proto);
+			break;
+		default:
+			printf("unknown redirect mode: %u\n", r->mode);
+			break; 
+		}
+		if (r->alink[0] == NULL) {
+			panic_err = "LibAliasRedirect* returned NULL";
+			goto bad;
+		} else /* LSNAT handling. */
+			for (i = 0; i < r->spool_cnt; i++) {
+				ser_s = (struct cfg_spool *)&buf[off];
+				s = malloc(SOF_REDIR, M_IPFW, 
+				    M_WAITOK | M_ZERO);
+				memcpy(s, ser_s, SOF_SPOOL);
+				LibAliasAddServer(ptr->lib, r->alink[0], 
+				    s->addr, htons(s->port));						  
+				off += SOF_SPOOL;
+				/* Hook spool entry. */
+				HOOK_SPOOL(&r->spool_chain, s);
+			}
+		/* And finally hook this redir entry. */
+		HOOK_REDIR(&ptr->redir_chain, r);
+	}
+	return (1);
+bad:
+	/* something really bad happened: panic! */
+	panic("%s\n", panic_err);
+}
+
 /*
  * The main check routine for the firewall.
  *
@@ -3257,6 +3437,177 @@ check_body:
 				    IP_FW_NETGRAPH : IP_FW_NGTEE;
 				goto done;
 
+			case O_NAT: {
+				struct cfg_nat *t;
+				struct mbuf *mcl;
+				/* XXX - libalias duct tape */
+				int ldt; 
+				char *c;
+				
+				ldt = 0;
+				args->rule = f;	/* Report matching rule. */
+				retval = 0;
+				t = ((ipfw_insn_nat *)cmd)->nat;
+				if (t == NULL) {
+					t = lookup_nat(cmd->arg1);
+					if (t == NULL) {
+						retval = IP_FW_DENY;
+						goto done;
+					} else 
+						((ipfw_insn_nat *)cmd)->nat = 
+						    t;
+				}
+				if ((mcl = m_megapullup(m, m->m_pkthdr.len)) ==
+				    NULL)
+					goto badnat;
+				ip = mtod(mcl, struct ip *);
+				if (args->eh == NULL) {
+					ip->ip_len = htons(ip->ip_len);
+					ip->ip_off = htons(ip->ip_off);
+				}
+
+				/* 
+				 * XXX - Libalias checksum offload 'duct tape':
+				 * 
+				 * locally generated packets have only
+				 * pseudo-header checksum calculated
+				 * and libalias will screw it[1], so
+				 * mark them for later fix.  Moreover
+				 * there are cases when libalias
+				 * modify tcp packet data[2], mark it
+				 * for later fix too.
+				 *
+				 * [1] libalias was never meant to run
+				 * in kernel, so it doesn't have any
+				 * knowledge about checksum
+				 * offloading, and it expects a packet
+				 * with a full internet
+				 * checksum. Unfortunately, packets
+				 * generated locally will have just the
+				 * pseudo header calculated, and when
+				 * libalias tries to adjust the
+				 * checksum it will actually screw it.
+				 *
+				 * [2] when libalias modify tcp's data
+				 * content, full TCP checksum has to
+				 * be recomputed: the problem is that
+				 * libalias doesn't have any idea
+				 * about checksum offloading To
+				 * workaround this, we do not do
+				 * checksumming in LibAlias, but only
+				 * mark the packets in th_x2 field. If
+				 * we receive a marked packet, we
+				 * calculate correct checksum for it
+				 * aware of offloading.  Why such a
+				 * terrible hack instead of
+				 * recalculating checksum for each
+				 * packet?  Because the previous
+				 * checksum was not checked!
+				 * Recalculating checksums for EVERY
+				 * packet will hide ALL transmission
+				 * errors. Yes, marked packets still
+				 * suffer from this problem. But,
+				 * sigh, natd(8) has this problem,
+				 * too.
+				 *
+				 * TODO: -make libalias mbuf aware (so
+				 * it can handle delayed checksum and tso)
+				 */
+
+				if (mcl->m_pkthdr.rcvif == NULL && 
+				    mcl->m_pkthdr.csum_flags & 
+				    CSUM_DELAY_DATA)
+					ldt = 1;
+
+				c = mtod(mcl, char *);
+				if (oif == NULL)
+					retval = LibAliasIn(t->lib, c, 
+					    MCLBYTES);
+				else
+					retval = LibAliasOut(t->lib, c, 
+					    MCLBYTES);
+				if (retval != PKT_ALIAS_OK) {
+					/* XXX - should i add some logging? */
+					m_free(mcl);
+				badnat:
+					args->m = NULL;
+					retval = IP_FW_DENY;
+					goto done;
+				}
+				mcl->m_pkthdr.len = mcl->m_len = 
+				    ntohs(ip->ip_len);
+
+				/* 
+				 * XXX - libalias checksum offload 
+				 * 'duct tape' (see above) 
+				 */
+
+				if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 
+				    ip->ip_p == IPPROTO_TCP) {
+					struct tcphdr 	*th; 
+
+					th = (struct tcphdr *)(ip + 1);
+					if (th->th_x2) 
+						ldt = 1;
+				}
+
+				if (ldt) {
+					struct tcphdr 	*th;
+					struct udphdr 	*uh;
+					u_short cksum;
+
+					ip->ip_len = ntohs(ip->ip_len);
+					cksum = in_pseudo(
+						ip->ip_src.s_addr,
+						ip->ip_dst.s_addr, 
+						htons(ip->ip_p + ip->ip_len - 
+					            (ip->ip_hl << 2))
+						);
+					
+					switch (ip->ip_p) {
+					case IPPROTO_TCP:
+						th = (struct tcphdr *)(ip + 1);
+						/* 
+						 * Maybe it was set in 
+						 * libalias... 
+						 */
+						th->th_x2 = 0;
+						th->th_sum = cksum;
+						mcl->m_pkthdr.csum_data = 
+						    offsetof(struct tcphdr,
+						    th_sum);
+						break;
+					case IPPROTO_UDP:
+						uh = (struct udphdr *)(ip + 1);
+						uh->uh_sum = cksum;
+						mcl->m_pkthdr.csum_data = 
+						    offsetof(struct udphdr,
+						    uh_sum);
+						break;						
+					}
+					/* 
+					 * No hw checksum offloading: do it 
+					 * by ourself. 
+					 */
+					if ((mcl->m_pkthdr.csum_flags & 
+					     CSUM_DELAY_DATA) == 0) {
+						in_delayed_cksum(mcl);
+						mcl->m_pkthdr.csum_flags &= 
+						    ~CSUM_DELAY_DATA;
+					}
+					ip->ip_len = htons(ip->ip_len);
+				}
+
+				if (args->eh == NULL) {
+					ip->ip_len = ntohs(ip->ip_len);
+					ip->ip_off = ntohs(ip->ip_off);
+				}
+
+				args->m = mcl;
+				retval = IP_FW_NAT; 
+				goto done;
+			}
+
 			default:
 				panic("-- unknown opcode %d\n", cmd->opcode);
 			} /* end of switch() on opcodes */
@@ -3826,6 +4177,10 @@ check_ipfw_struct(struct ip_fw *rule, int size)
 				return EINVAL;
 			else
 				goto check_size;
+		case O_NAT:
+			if (cmdlen != F_INSN_SIZE(ipfw_insn_nat))
+ 				goto bad_size;		
+ 			goto check_action;
 		case O_FORWARD_MAC: /* XXX not implemented yet */
 		case O_CHECK_STATE:
 		case O_COUNT:
@@ -4201,6 +4556,185 @@ ipfw_ctl(struct sockopt *sopt)
 		}
 		break;
 
+	case IP_FW_NAT_CFG:
+	{
+		struct cfg_nat *ptr, *ser_n;
+		char *buf;
+
+		buf = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO);
+		error = sooptcopyin(sopt, buf, NAT_BUF_LEN, 
+		    sizeof(struct cfg_nat));
+		ser_n = (struct cfg_nat *)buf;
+
+		/* 
+		 * Find/create nat rule.
+		 */
+		IPFW_WLOCK(&layer3_chain);
+		ptr = lookup_nat(ser_n->id);		
+		if (ptr == NULL) {
+			/* New rule: allocate and init new instance. */
+			ptr = malloc(sizeof(struct cfg_nat), 
+		            M_IPFW, M_NOWAIT | M_ZERO);
+			if (ptr == NULL) {
+				IPFW_WUNLOCK(&layer3_chain);				
+				free(buf, M_IPFW);
+				return (ENOSPC);				
+			}
+			ptr->lib = LibAliasInit(NULL);
+			if (ptr->lib == NULL) {
+				IPFW_WUNLOCK(&layer3_chain);
+				free(ptr, M_IPFW);
+				free(buf, M_IPFW);		
+				return (EINVAL);
+			}
+			LIST_INIT(&ptr->redir_chain);
+		} else {
+			/* Entry already present: temporarly unhook it. */
+			UNHOOK_NAT(ptr);
+			flush_nat_ptrs(ser_n->id);
+		}
+		IPFW_WUNLOCK(&layer3_chain);
+
+		/* 
+		 * Basic nat configuration.
+		 */
+		ptr->id = ser_n->id;
+		/* 
+		 * XXX - what if this rule doesn't nat any ip and just 
+		 * redirect? 
+		 * do we set aliasaddress to 0.0.0.0?
+		 */
+		ptr->ip = ser_n->ip;
+		ptr->redir_cnt = ser_n->redir_cnt;
+		ptr->mode = ser_n->mode;
+		LibAliasSetMode(ptr->lib, ser_n->mode, ser_n->mode);
+		LibAliasSetAddress(ptr->lib, ptr->ip);
+		memcpy(ptr->if_name, ser_n->if_name, IF_NAMESIZE);
+
+		/* 
+		 * Redir and LSNAT configuration.
+		 */
+		/* Delete old cfgs. */
+		del_redir_spool_cfg(ptr, &ptr->redir_chain);
+		/* Add new entries. */
+		add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr);
+		free(buf, M_IPFW);
+		IPFW_WLOCK(&layer3_chain);
+		HOOK_NAT(&layer3_chain.nat, ptr);
+		IPFW_WUNLOCK(&layer3_chain);
+	}
+	break;
+
+	case IP_FW_NAT_DEL:
+	{
+		struct cfg_nat *ptr;
+		int i;
+		
+		error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
+		IPFW_WLOCK(&layer3_chain);
+		ptr = lookup_nat(i);
+		if (ptr == NULL) {
+			error = EINVAL;
+			IPFW_WUNLOCK(&layer3_chain);
+			break;
+		}
+		UNHOOK_NAT(ptr);
+		flush_nat_ptrs(i);
+		IPFW_WUNLOCK(&layer3_chain);
+		del_redir_spool_cfg(ptr, &ptr->redir_chain);
+		LibAliasUninit(ptr->lib);
+		free(ptr, M_IPFW);
+	}
+	break;
+
+	case IP_FW_NAT_GET_CONFIG:
+	{
+		uint8_t *data;
+		struct cfg_nat *n;
+		struct cfg_redir *r;
+		struct cfg_spool *s;
+		int nat_cnt, off;
+		
+		nat_cnt = 0;
+		off = sizeof(nat_cnt);
+
+		data = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO);
+		IPFW_RLOCK(&layer3_chain);
+		/* Serialize all the data. */
+		LIST_FOREACH(n, &layer3_chain.nat, _next) {
+			nat_cnt++;
+			if (off + SOF_NAT < NAT_BUF_LEN) {
+				bcopy(n, &data[off], SOF_NAT);
+				off += SOF_NAT;
+				LIST_FOREACH(r, &n->redir_chain, _next) {
+					if (off + SOF_REDIR < NAT_BUF_LEN) {
+						bcopy(r, &data[off], 
+						    SOF_REDIR);
+						off += SOF_REDIR;
+						LIST_FOREACH(s, &r->spool_chain, 
+						    _next) {							     
+							if (off + SOF_SPOOL < 
+							    NAT_BUF_LEN) {
+								bcopy(s, 
+								    &data[off],
+								    SOF_SPOOL);
+								off += 
+								    SOF_SPOOL;
+							} else
+								goto nospace;
+						}
+					} else
+						goto nospace;
+				}
+			} else
+				goto nospace;
+		}
+		bcopy(&nat_cnt, data, sizeof(nat_cnt));
+		IPFW_RUNLOCK(&layer3_chain);
+		error = sooptcopyout(sopt, data, NAT_BUF_LEN);
+		free(data, M_IPFW);
+		break;
+	nospace:
+		IPFW_RUNLOCK(&layer3_chain);
+		printf("serialized data buffer not big enough:"
+		    "please increase NAT_BUF_LEN\n");
+		free(data, M_IPFW);
+	}
+	break;
+
+	case IP_FW_NAT_GET_LOG:
+	{
+		uint8_t *data;
+		struct cfg_nat *ptr;
+		int i, size, cnt, sof;
+
+		data = NULL;
+		sof = LIBALIAS_BUF_SIZE;
+		cnt = 0;
+
+		IPFW_RLOCK(&layer3_chain);
+		size = i = 0;
+		LIST_FOREACH(ptr, &layer3_chain.nat, _next) {
+			if (ptr->lib->logDesc == NULL) 
+				continue;
+			cnt++;
+			size = cnt * (sof + sizeof(int));
+			data = realloc(data, size, M_IPFW, M_NOWAIT | M_ZERO);
+			if (data == NULL) {
+				IPFW_RUNLOCK(&layer3_chain);
+				return (ENOSPC);
+			}
+			bcopy(&ptr->id, &data[i], sizeof(int));
+			i += sizeof(int);
+			bcopy(ptr->lib->logDesc, &data[i], sof);
+			i += sof;
+		}
+		IPFW_RUNLOCK(&layer3_chain);
+		error = sooptcopyout(sopt, data, size);
+		free(data, M_IPFW);
+	}
+	break;
+
 	default:
 		printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name);
 		error = EINVAL;
@@ -4372,8 +4906,10 @@ ipfw_init(void)
 	}
 	ip_fw_ctl_ptr = ipfw_ctl;
 	ip_fw_chk_ptr = ipfw_chk;
-	callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL);
-
+	callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL);	
+	LIST_INIT(&layer3_chain.nat);
+	ifaddr_event_tag = EVENTHANDLER_REGISTER(ifaddr_event, ifaddr_change, 
+	    NULL, EVENTHANDLER_PRI_ANY);
 	return (0);
 }
 
@@ -4381,12 +4917,20 @@ void
 ipfw_destroy(void)
 {
 	struct ip_fw *reap;
+	struct cfg_nat *ptr, *ptr_temp;
 
 	ip_fw_chk_ptr = NULL;
 	ip_fw_ctl_ptr = NULL;
 	callout_drain(&ipfw_timeout);
 	IPFW_WLOCK(&layer3_chain);
 	flush_tables(&layer3_chain);
+	LIST_FOREACH_SAFE(ptr, &layer3_chain.nat, _next, ptr_temp) {
+		LIST_REMOVE(ptr, _next);
+		del_redir_spool_cfg(ptr, &ptr->redir_chain);
+		LibAliasUninit(ptr->lib);
+		free(ptr, M_IPFW);
+	}
+	EVENTHANDLER_DEREGISTER(ifaddr_event, ifaddr_event_tag);
 	layer3_chain.reap = NULL;
 	free_chain(&layer3_chain, 1 /* kill default rule */);
 	reap = layer3_chain.reap, layer3_chain.reap = NULL;