1 /*- 2 * Copyright 2005, Gleb Smirnoff <glebius@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include "opt_inet.h" 30 #include "opt_inet6.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/mbuf.h> 37 #include <sys/malloc.h> 38 #include <sys/ctype.h> 39 #include <sys/errno.h> 40 #include <sys/rwlock.h> 41 #include <sys/socket.h> 42 #include <sys/syslog.h> 43 44 #include <net/if.h> 45 46 #include <netinet/in.h> 47 #include <netinet/in_systm.h> 48 #include <netinet/in_var.h> 49 #include <netinet/ip_var.h> 50 #include <netinet/ip_fw.h> 51 #include <netinet/ip.h> 52 #include <netinet/ip6.h> 53 #include <netinet6/ip6_var.h> 54 55 #include <netpfil/ipfw/ip_fw_private.h> 56 57 #include <netgraph/ng_message.h> 58 #include <netgraph/ng_parse.h> 59 #include <netgraph/ng_ipfw.h> 60 #include <netgraph/netgraph.h> 61 62 static int ng_ipfw_mod_event(module_t mod, int event, void *data); 63 static ng_constructor_t ng_ipfw_constructor; 64 static ng_shutdown_t ng_ipfw_shutdown; 65 static ng_newhook_t ng_ipfw_newhook; 66 static ng_connect_t ng_ipfw_connect; 67 static ng_findhook_t ng_ipfw_findhook; 68 static ng_rcvdata_t ng_ipfw_rcvdata; 69 static ng_disconnect_t ng_ipfw_disconnect; 70 71 static hook_p ng_ipfw_findhook1(node_p, u_int16_t ); 72 static int ng_ipfw_input(struct mbuf **, int, struct ip_fw_args *, 73 int); 74 75 /* We have only one node */ 76 static node_p fw_node; 77 78 /* Netgraph node type descriptor */ 79 static struct ng_type ng_ipfw_typestruct = { 80 .version = NG_ABI_VERSION, 81 .name = NG_IPFW_NODE_TYPE, 82 .mod_event = ng_ipfw_mod_event, 83 .constructor = ng_ipfw_constructor, 84 .shutdown = ng_ipfw_shutdown, 85 .newhook = ng_ipfw_newhook, 86 .connect = ng_ipfw_connect, 87 .findhook = ng_ipfw_findhook, 88 .rcvdata = ng_ipfw_rcvdata, 89 .disconnect = ng_ipfw_disconnect, 90 }; 91 NETGRAPH_INIT(ipfw, &ng_ipfw_typestruct); 92 MODULE_DEPEND(ng_ipfw, ipfw, 2, 2, 2); 93 94 /* Information we store for each hook */ 95 struct ng_ipfw_hook_priv { 96 hook_p hook; 97 u_int16_t rulenum; 98 }; 99 typedef struct ng_ipfw_hook_priv *hpriv_p; 100 101 static int 102 ng_ipfw_mod_event(module_t mod, int event, void *data) 103 { 104 int error = 0; 105 106 switch (event) { 107 case MOD_LOAD: 108 109 if (ng_ipfw_input_p != NULL) { 110 error = EEXIST; 111 break; 112 } 113 114 /* Setup node without any private data */ 115 if ((error = ng_make_node_common(&ng_ipfw_typestruct, &fw_node)) 116 != 0) { 117 log(LOG_ERR, "%s: can't create ng_ipfw node", __func__); 118 break; 119 }; 120 121 /* Try to name node */ 122 if (ng_name_node(fw_node, "ipfw") != 0) 123 log(LOG_WARNING, "%s: failed to name node \"ipfw\"", 124 __func__); 125 126 /* Register hook */ 127 ng_ipfw_input_p = ng_ipfw_input; 128 break; 129 130 case MOD_UNLOAD: 131 /* 132 * This won't happen if a node exists. 133 * ng_ipfw_input_p is already cleared. 134 */ 135 break; 136 137 default: 138 error = EOPNOTSUPP; 139 break; 140 } 141 142 return (error); 143 } 144 145 static int 146 ng_ipfw_constructor(node_p node) 147 { 148 return (EINVAL); /* Only one node */ 149 } 150 151 static int 152 ng_ipfw_newhook(node_p node, hook_p hook, const char *name) 153 { 154 hpriv_p hpriv; 155 u_int16_t rulenum; 156 const char *cp; 157 char *endptr; 158 159 /* Protect from leading zero */ 160 if (name[0] == '0' && name[1] != '\0') 161 return (EINVAL); 162 163 /* Check that name contains only digits */ 164 for (cp = name; *cp != '\0'; cp++) 165 if (!isdigit(*cp)) 166 return (EINVAL); 167 168 /* Convert it to integer */ 169 rulenum = (u_int16_t)strtol(name, &endptr, 10); 170 if (*endptr != '\0') 171 return (EINVAL); 172 173 /* Allocate memory for this hook's private data */ 174 hpriv = malloc(sizeof(*hpriv), M_NETGRAPH, M_NOWAIT | M_ZERO); 175 if (hpriv== NULL) 176 return (ENOMEM); 177 178 hpriv->hook = hook; 179 hpriv->rulenum = rulenum; 180 181 NG_HOOK_SET_PRIVATE(hook, hpriv); 182 183 return(0); 184 } 185 186 /* 187 * Set hooks into queueing mode, to avoid recursion between 188 * netgraph layer and ip_{input,output}. 189 */ 190 static int 191 ng_ipfw_connect(hook_p hook) 192 { 193 NG_HOOK_FORCE_QUEUE(hook); 194 return (0); 195 } 196 197 /* Look up hook by name */ 198 static hook_p 199 ng_ipfw_findhook(node_p node, const char *name) 200 { 201 u_int16_t n; /* numeric representation of hook */ 202 char *endptr; 203 204 n = (u_int16_t)strtol(name, &endptr, 10); 205 if (*endptr != '\0') 206 return NULL; 207 return ng_ipfw_findhook1(node, n); 208 } 209 210 /* Look up hook by rule number */ 211 static hook_p 212 ng_ipfw_findhook1(node_p node, u_int16_t rulenum) 213 { 214 hook_p hook; 215 hpriv_p hpriv; 216 217 LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) { 218 hpriv = NG_HOOK_PRIVATE(hook); 219 if (NG_HOOK_IS_VALID(hook) && (hpriv->rulenum == rulenum)) 220 return (hook); 221 } 222 223 return (NULL); 224 } 225 226 227 static int 228 ng_ipfw_rcvdata(hook_p hook, item_p item) 229 { 230 struct m_tag *tag; 231 struct ipfw_rule_ref *r; 232 struct mbuf *m; 233 struct ip *ip; 234 235 NGI_GET_M(item, m); 236 NG_FREE_ITEM(item); 237 238 tag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 239 if (tag == NULL) { 240 NG_FREE_M(m); 241 return (EINVAL); /* XXX: find smth better */ 242 }; 243 244 if (m->m_len < sizeof(struct ip) && 245 (m = m_pullup(m, sizeof(struct ip))) == NULL) 246 return (ENOBUFS); 247 248 ip = mtod(m, struct ip *); 249 250 r = (struct ipfw_rule_ref *)(tag + 1); 251 if (r->info & IPFW_INFO_IN) { 252 switch (ip->ip_v) { 253 #ifdef INET 254 case IPVERSION: 255 ip_input(m); 256 return (0); 257 #endif 258 #ifdef INET6 259 case IPV6_VERSION >> 4: 260 ip6_input(m); 261 return (0); 262 #endif 263 } 264 } else { 265 switch (ip->ip_v) { 266 #ifdef INET 267 case IPVERSION: 268 return (ip_output(m, NULL, NULL, IP_FORWARDING, 269 NULL, NULL)); 270 #endif 271 #ifdef INET6 272 case IPV6_VERSION >> 4: 273 return (ip6_output(m, NULL, NULL, 0, NULL, 274 NULL, NULL)); 275 #endif 276 } 277 } 278 279 /* unknown IP protocol version */ 280 NG_FREE_M(m); 281 return (EPROTONOSUPPORT); 282 } 283 284 static int 285 ng_ipfw_input(struct mbuf **m0, int dir, struct ip_fw_args *fwa, int tee) 286 { 287 struct mbuf *m; 288 struct ip *ip; 289 hook_p hook; 290 int error = 0; 291 292 /* 293 * Node must be loaded and corresponding hook must be present. 294 */ 295 if (fw_node == NULL || 296 (hook = ng_ipfw_findhook1(fw_node, fwa->rule.info)) == NULL) 297 return (ESRCH); /* no hook associated with this rule */ 298 299 /* 300 * We have two modes: in normal mode we add a tag to packet, which is 301 * important to return packet back to IP stack. In tee mode we make 302 * a copy of a packet and forward it into netgraph without a tag. 303 */ 304 if (tee == 0) { 305 struct m_tag *tag; 306 struct ipfw_rule_ref *r; 307 m = *m0; 308 *m0 = NULL; /* it belongs now to netgraph */ 309 310 tag = m_tag_alloc(MTAG_IPFW_RULE, 0, sizeof(*r), 311 M_NOWAIT|M_ZERO); 312 if (tag == NULL) { 313 m_freem(m); 314 return (ENOMEM); 315 } 316 r = (struct ipfw_rule_ref *)(tag + 1); 317 *r = fwa->rule; 318 r->info &= IPFW_ONEPASS; /* keep this info */ 319 r->info |= dir ? IPFW_INFO_IN : IPFW_INFO_OUT; 320 m_tag_prepend(m, tag); 321 322 } else 323 if ((m = m_dup(*m0, M_NOWAIT)) == NULL) 324 return (ENOMEM); /* which is ignored */ 325 326 if (m->m_len < sizeof(struct ip) && 327 (m = m_pullup(m, sizeof(struct ip))) == NULL) 328 return (EINVAL); 329 330 ip = mtod(m, struct ip *); 331 332 NG_SEND_DATA_ONLY(error, hook, m); 333 334 return (error); 335 } 336 337 static int 338 ng_ipfw_shutdown(node_p node) 339 { 340 341 /* 342 * After our single node has been removed, 343 * the only thing that can be done is 344 * 'kldunload ng_ipfw.ko' 345 */ 346 ng_ipfw_input_p = NULL; 347 NG_NODE_UNREF(node); 348 return (0); 349 } 350 351 static int 352 ng_ipfw_disconnect(hook_p hook) 353 { 354 const hpriv_p hpriv = NG_HOOK_PRIVATE(hook); 355 356 free(hpriv, M_NETGRAPH); 357 NG_HOOK_SET_PRIVATE(hook, NULL); 358 359 return (0); 360 } 361