1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 2005, Gleb Smirnoff <glebius@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 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 #include <net/if_var.h> 46 47 #include <netinet/in.h> 48 #include <netinet/in_systm.h> 49 #include <netinet/in_var.h> 50 #include <netinet/ip_var.h> 51 #include <netinet/ip_fw.h> 52 #include <netinet/ip.h> 53 #include <netinet/ip6.h> 54 #include <netinet6/ip6_var.h> 55 56 #include <netpfil/ipfw/ip_fw_private.h> 57 58 #include <netgraph/ng_message.h> 59 #include <netgraph/ng_parse.h> 60 #include <netgraph/ng_ipfw.h> 61 #include <netgraph/netgraph.h> 62 63 static int ng_ipfw_mod_event(module_t mod, int event, void *data); 64 static ng_constructor_t ng_ipfw_constructor; 65 static ng_shutdown_t ng_ipfw_shutdown; 66 static ng_newhook_t ng_ipfw_newhook; 67 static ng_connect_t ng_ipfw_connect; 68 static ng_findhook_t ng_ipfw_findhook; 69 static ng_rcvdata_t ng_ipfw_rcvdata; 70 static ng_disconnect_t ng_ipfw_disconnect; 71 72 static hook_p ng_ipfw_findhook1(node_p, uint32_t ); 73 static int ng_ipfw_input(struct mbuf **, struct ip_fw_args *, bool); 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, 3, 3, 3); 93 94 /* Information we store for each hook */ 95 struct ng_ipfw_hook_priv { 96 hook_p hook; 97 uint32_t cookie; 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 uint32_t cookie; 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 cookie = (uint32_t)strtoul(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->cookie = cookie; 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 uint32_t n; /* numeric representation of hook */ 202 char *endptr; 203 204 n = (uint32_t)strtoul(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, uint32_t cookie) 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->cookie == cookie)) 220 return (hook); 221 } 222 223 return (NULL); 224 } 225 226 static int 227 ng_ipfw_rcvdata(hook_p hook, item_p item) 228 { 229 struct m_tag *tag; 230 struct ipfw_rule_ref *r; 231 struct mbuf *m; 232 struct ip *ip; 233 234 NGI_GET_M(item, m); 235 NG_FREE_ITEM(item); 236 237 tag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 238 if (tag == NULL) { 239 NG_FREE_M(m); 240 return (EINVAL); /* XXX: find smth better */ 241 } 242 243 if (m->m_len < sizeof(struct ip) && 244 (m = m_pullup(m, sizeof(struct ip))) == NULL) 245 return (ENOBUFS); 246 247 ip = mtod(m, struct ip *); 248 249 r = (struct ipfw_rule_ref *)(tag + 1); 250 if (r->info & IPFW_INFO_IN) { 251 switch (ip->ip_v) { 252 #ifdef INET 253 case IPVERSION: 254 ip_input(m); 255 return (0); 256 #endif 257 #ifdef INET6 258 case IPV6_VERSION >> 4: 259 ip6_input(m); 260 return (0); 261 #endif 262 } 263 } else { 264 switch (ip->ip_v) { 265 #ifdef INET 266 case IPVERSION: 267 return (ip_output(m, NULL, NULL, IP_FORWARDING, 268 NULL, NULL)); 269 #endif 270 #ifdef INET6 271 case IPV6_VERSION >> 4: 272 return (ip6_output(m, NULL, NULL, 0, NULL, 273 NULL, NULL)); 274 #endif 275 } 276 } 277 278 /* unknown IP protocol version */ 279 NG_FREE_M(m); 280 return (EPROTONOSUPPORT); 281 } 282 283 static int 284 ng_ipfw_input(struct mbuf **m0, struct ip_fw_args *fwa, bool tee) 285 { 286 struct mbuf *m; 287 hook_p hook; 288 int error = 0; 289 290 /* 291 * Node must be loaded and corresponding hook must be present. 292 */ 293 if (fw_node == NULL || 294 (hook = ng_ipfw_findhook1(fw_node, fwa->rule.info)) == NULL) 295 return (ESRCH); /* no hook associated with this rule */ 296 297 /* 298 * We have two modes: in normal mode we add a tag to packet, which is 299 * important to return packet back to IP stack. In tee mode we make 300 * a copy of a packet and forward it into netgraph without a tag. 301 */ 302 if (tee == false) { 303 struct m_tag *tag; 304 struct ipfw_rule_ref *r; 305 m = *m0; 306 *m0 = NULL; /* it belongs now to netgraph */ 307 308 tag = m_tag_alloc(MTAG_IPFW_RULE, 0, sizeof(*r), 309 M_NOWAIT|M_ZERO); 310 if (tag == NULL) { 311 m_freem(m); 312 return (ENOMEM); 313 } 314 r = (struct ipfw_rule_ref *)(tag + 1); 315 *r = fwa->rule; 316 r->info &= IPFW_ONEPASS; /* keep this info */ 317 r->info |= (fwa->flags & IPFW_ARGS_IN) ? 318 IPFW_INFO_IN : IPFW_INFO_OUT; 319 m_tag_prepend(m, tag); 320 321 } else 322 if ((m = m_dup(*m0, M_NOWAIT)) == NULL) 323 return (ENOMEM); /* which is ignored */ 324 325 if (m->m_len < sizeof(struct ip) && 326 (m = m_pullup(m, sizeof(struct ip))) == NULL) 327 return (EINVAL); 328 329 NG_SEND_DATA_ONLY(error, hook, m); 330 331 return (error); 332 } 333 334 static int 335 ng_ipfw_shutdown(node_p node) 336 { 337 338 /* 339 * After our single node has been removed, 340 * the only thing that can be done is 341 * 'kldunload ng_ipfw.ko' 342 */ 343 ng_ipfw_input_p = NULL; 344 NG_NODE_UNREF(node); 345 return (0); 346 } 347 348 static int 349 ng_ipfw_disconnect(hook_p hook) 350 { 351 const hpriv_p hpriv = NG_HOOK_PRIVATE(hook); 352 353 free(hpriv, M_NETGRAPH); 354 NG_HOOK_SET_PRIVATE(hook, NULL); 355 356 return (0); 357 } 358