Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libipq.c |
| 3 | * |
| 4 | * IPQ userspace library. |
| 5 | * |
| 6 | * Please note that this library is still developmental, and there may |
| 7 | * be some API changes. |
| 8 | * |
James Morris | ef798b9 | 2001-05-30 00:48:03 +0000 | [diff] [blame] | 9 | * Author: James Morris <jmorris@intercode.com.au> |
| 10 | * |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 11 | * 07-11-2001 Modified by Fernando Anton to add support for IPv6. |
| 12 | * |
James Morris | ef798b9 | 2001-05-30 00:48:03 +0000 | [diff] [blame] | 13 | * Copyright (c) 2000-2001 Netfilter Core Team |
| 14 | * |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 15 | * This program is free software; you can redistribute it and/or modify |
| 16 | * it under the terms of the GNU General Public License as published by |
| 17 | * the Free Software Foundation; either version 2 of the License, or |
| 18 | * (at your option) any later version. |
| 19 | * |
| 20 | * This program is distributed in the hope that it will be useful, |
| 21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 23 | * GNU General Public License for more details. |
| 24 | * |
| 25 | */ |
| 26 | |
| 27 | #include <stdlib.h> |
| 28 | #include <stdio.h> |
| 29 | #include <string.h> |
| 30 | #include <unistd.h> |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 31 | #include <sys/time.h> |
| 32 | #include <sys/types.h> |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 33 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 34 | #include <libipq/libipq.h> |
Jan Engelhardt | e37c2d0 | 2009-02-12 15:07:15 +0100 | [diff] [blame] | 35 | #include <netinet/in.h> |
| 36 | #include <linux/netfilter.h> |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 37 | |
| 38 | /**************************************************************************** |
| 39 | * |
| 40 | * Private interface |
| 41 | * |
| 42 | ****************************************************************************/ |
| 43 | |
| 44 | enum { |
| 45 | IPQ_ERR_NONE = 0, |
| 46 | IPQ_ERR_IMPL, |
| 47 | IPQ_ERR_HANDLE, |
| 48 | IPQ_ERR_SOCKET, |
| 49 | IPQ_ERR_BIND, |
| 50 | IPQ_ERR_BUFFER, |
| 51 | IPQ_ERR_RECV, |
| 52 | IPQ_ERR_NLEOF, |
| 53 | IPQ_ERR_ADDRLEN, |
| 54 | IPQ_ERR_STRUNC, |
| 55 | IPQ_ERR_RTRUNC, |
| 56 | IPQ_ERR_NLRECV, |
| 57 | IPQ_ERR_SEND, |
| 58 | IPQ_ERR_SUPP, |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 59 | IPQ_ERR_RECVBUF, |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 60 | IPQ_ERR_TIMEOUT, |
| 61 | IPQ_ERR_PROTOCOL |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 62 | }; |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 63 | #define IPQ_MAXERR IPQ_ERR_PROTOCOL |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 64 | |
| 65 | struct ipq_errmap_t { |
| 66 | int errcode; |
| 67 | char *message; |
| 68 | } ipq_errmap[] = { |
| 69 | { IPQ_ERR_NONE, "Unknown error" }, |
| 70 | { IPQ_ERR_IMPL, "Implementation error" }, |
| 71 | { IPQ_ERR_HANDLE, "Unable to create netlink handle" }, |
| 72 | { IPQ_ERR_SOCKET, "Unable to create netlink socket" }, |
| 73 | { IPQ_ERR_BIND, "Unable to bind netlink socket" }, |
| 74 | { IPQ_ERR_BUFFER, "Unable to allocate buffer" }, |
| 75 | { IPQ_ERR_RECV, "Failed to receive netlink message" }, |
| 76 | { IPQ_ERR_NLEOF, "Received EOF on netlink socket" }, |
| 77 | { IPQ_ERR_ADDRLEN, "Invalid peer address length" }, |
| 78 | { IPQ_ERR_STRUNC, "Sent message truncated" }, |
| 79 | { IPQ_ERR_RTRUNC, "Received message truncated" }, |
| 80 | { IPQ_ERR_NLRECV, "Received error from netlink" }, |
| 81 | { IPQ_ERR_SEND, "Failed to send netlink message" }, |
| 82 | { IPQ_ERR_SUPP, "Operation not supported" }, |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 83 | { IPQ_ERR_RECVBUF, "Receive buffer size invalid" }, |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 84 | { IPQ_ERR_TIMEOUT, "Timeout"}, |
| 85 | { IPQ_ERR_PROTOCOL, "Invalid protocol specified" } |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 86 | }; |
| 87 | |
| 88 | static int ipq_errno = IPQ_ERR_NONE; |
| 89 | |
| 90 | static ssize_t ipq_netlink_sendto(const struct ipq_handle *h, |
| 91 | const void *msg, size_t len); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 92 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 93 | static ssize_t ipq_netlink_recvfrom(const struct ipq_handle *h, |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 94 | unsigned char *buf, size_t len, |
| 95 | int timeout); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 96 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 97 | static ssize_t ipq_netlink_sendmsg(const struct ipq_handle *h, |
| 98 | const struct msghdr *msg, |
| 99 | unsigned int flags); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 100 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 101 | static char *ipq_strerror(int errcode); |
| 102 | |
| 103 | static ssize_t ipq_netlink_sendto(const struct ipq_handle *h, |
| 104 | const void *msg, size_t len) |
| 105 | { |
| 106 | int status = sendto(h->fd, msg, len, 0, |
| 107 | (struct sockaddr *)&h->peer, sizeof(h->peer)); |
| 108 | if (status < 0) |
| 109 | ipq_errno = IPQ_ERR_SEND; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 110 | return status; |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 111 | } |
| 112 | |
| 113 | static ssize_t ipq_netlink_sendmsg(const struct ipq_handle *h, |
| 114 | const struct msghdr *msg, |
| 115 | unsigned int flags) |
| 116 | { |
| 117 | int status = sendmsg(h->fd, msg, flags); |
| 118 | if (status < 0) |
| 119 | ipq_errno = IPQ_ERR_SEND; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 120 | return status; |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static ssize_t ipq_netlink_recvfrom(const struct ipq_handle *h, |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 124 | unsigned char *buf, size_t len, |
| 125 | int timeout) |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 126 | { |
Harald Welte | efa8fc2 | 2005-07-19 22:03:49 +0000 | [diff] [blame] | 127 | unsigned int addrlen; |
| 128 | int status; |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 129 | struct nlmsghdr *nlh; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 130 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 131 | if (len < sizeof(struct nlmsgerr)) { |
| 132 | ipq_errno = IPQ_ERR_RECVBUF; |
| 133 | return -1; |
| 134 | } |
| 135 | addrlen = sizeof(h->peer); |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 136 | |
| 137 | if (timeout != 0) { |
| 138 | int ret; |
| 139 | struct timeval tv; |
| 140 | fd_set read_fds; |
| 141 | |
| 142 | if (timeout < 0) { |
| 143 | /* non-block non-timeout */ |
| 144 | tv.tv_sec = 0; |
| 145 | tv.tv_usec = 0; |
| 146 | } else { |
| 147 | tv.tv_sec = timeout / 1000000; |
| 148 | tv.tv_usec = timeout % 1000000; |
| 149 | } |
| 150 | |
| 151 | FD_ZERO(&read_fds); |
| 152 | FD_SET(h->fd, &read_fds); |
| 153 | ret = select(h->fd+1, &read_fds, NULL, NULL, &tv); |
| 154 | if (ret < 0) { |
| 155 | if (errno == EINTR) { |
| 156 | return 0; |
| 157 | } else { |
| 158 | ipq_errno = IPQ_ERR_RECV; |
| 159 | return -1; |
| 160 | } |
| 161 | } |
| 162 | if (!FD_ISSET(h->fd, &read_fds)) { |
| 163 | ipq_errno = IPQ_ERR_TIMEOUT; |
| 164 | return 0; |
| 165 | } |
| 166 | } |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 167 | status = recvfrom(h->fd, buf, len, 0, |
| 168 | (struct sockaddr *)&h->peer, &addrlen); |
| 169 | if (status < 0) { |
| 170 | ipq_errno = IPQ_ERR_RECV; |
| 171 | return status; |
| 172 | } |
| 173 | if (addrlen != sizeof(h->peer)) { |
| 174 | ipq_errno = IPQ_ERR_RECV; |
| 175 | return -1; |
| 176 | } |
Harald Welte | e510597 | 2003-11-14 19:17:45 +0000 | [diff] [blame] | 177 | if (h->peer.nl_pid != 0) { |
| 178 | ipq_errno = IPQ_ERR_RECV; |
| 179 | return -1; |
| 180 | } |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 181 | if (status == 0) { |
| 182 | ipq_errno = IPQ_ERR_NLEOF; |
| 183 | return -1; |
| 184 | } |
| 185 | nlh = (struct nlmsghdr *)buf; |
| 186 | if (nlh->nlmsg_flags & MSG_TRUNC || nlh->nlmsg_len > status) { |
| 187 | ipq_errno = IPQ_ERR_RTRUNC; |
| 188 | return -1; |
| 189 | } |
| 190 | return status; |
| 191 | } |
| 192 | |
| 193 | static char *ipq_strerror(int errcode) |
| 194 | { |
| 195 | if (errcode < 0 || errcode > IPQ_MAXERR) |
| 196 | errcode = IPQ_ERR_IMPL; |
| 197 | return ipq_errmap[errcode].message; |
| 198 | } |
| 199 | |
| 200 | /**************************************************************************** |
| 201 | * |
| 202 | * Public interface |
| 203 | * |
| 204 | ****************************************************************************/ |
| 205 | |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 206 | /* |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 207 | * Create and initialise an ipq handle. |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 208 | */ |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 209 | struct ipq_handle *ipq_create_handle(u_int32_t flags, u_int32_t protocol) |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 210 | { |
| 211 | int status; |
| 212 | struct ipq_handle *h; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 213 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 214 | h = (struct ipq_handle *)malloc(sizeof(struct ipq_handle)); |
| 215 | if (h == NULL) { |
| 216 | ipq_errno = IPQ_ERR_HANDLE; |
| 217 | return NULL; |
| 218 | } |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 219 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 220 | memset(h, 0, sizeof(struct ipq_handle)); |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 221 | |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 222 | if (protocol == NFPROTO_IPV4) |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 223 | h->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_FIREWALL); |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 224 | else if (protocol == NFPROTO_IPV6) |
James Morris | ffe96c5 | 2001-11-24 15:09:19 +0000 | [diff] [blame] | 225 | h->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_IP6_FW); |
| 226 | else { |
| 227 | ipq_errno = IPQ_ERR_PROTOCOL; |
| 228 | free(h); |
| 229 | return NULL; |
| 230 | } |
| 231 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 232 | if (h->fd == -1) { |
| 233 | ipq_errno = IPQ_ERR_SOCKET; |
| 234 | close(h->fd); |
| 235 | free(h); |
| 236 | return NULL; |
| 237 | } |
| 238 | memset(&h->local, 0, sizeof(struct sockaddr_nl)); |
| 239 | h->local.nl_family = AF_NETLINK; |
| 240 | h->local.nl_pid = getpid(); |
| 241 | h->local.nl_groups = 0; |
| 242 | status = bind(h->fd, (struct sockaddr *)&h->local, sizeof(h->local)); |
| 243 | if (status == -1) { |
| 244 | ipq_errno = IPQ_ERR_BIND; |
| 245 | close(h->fd); |
| 246 | free(h); |
| 247 | return NULL; |
| 248 | } |
| 249 | memset(&h->peer, 0, sizeof(struct sockaddr_nl)); |
| 250 | h->peer.nl_family = AF_NETLINK; |
| 251 | h->peer.nl_pid = 0; |
| 252 | h->peer.nl_groups = 0; |
| 253 | return h; |
| 254 | } |
| 255 | |
| 256 | /* |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 257 | * No error condition is checked here at this stage, but it may happen |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 258 | * if/when reliable messaging is implemented. |
| 259 | */ |
| 260 | int ipq_destroy_handle(struct ipq_handle *h) |
| 261 | { |
| 262 | if (h) { |
| 263 | close(h->fd); |
| 264 | free(h); |
| 265 | } |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | int ipq_set_mode(const struct ipq_handle *h, |
| 270 | u_int8_t mode, size_t range) |
| 271 | { |
| 272 | struct { |
| 273 | struct nlmsghdr nlh; |
| 274 | ipq_peer_msg_t pm; |
| 275 | } req; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 276 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 277 | memset(&req, 0, sizeof(req)); |
| 278 | req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(req)); |
| 279 | req.nlh.nlmsg_flags = NLM_F_REQUEST; |
| 280 | req.nlh.nlmsg_type = IPQM_MODE; |
| 281 | req.nlh.nlmsg_pid = h->local.nl_pid; |
| 282 | req.pm.msg.mode.value = mode; |
| 283 | req.pm.msg.mode.range = range; |
| 284 | return ipq_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len); |
| 285 | } |
| 286 | |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 287 | /* |
| 288 | * timeout is in microseconds (1 second is 1000000 (1 million) microseconds) |
| 289 | * |
| 290 | */ |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 291 | ssize_t ipq_read(const struct ipq_handle *h, |
| 292 | unsigned char *buf, size_t len, int timeout) |
| 293 | { |
James Morris | dbd8a26 | 2001-09-21 11:59:23 +0000 | [diff] [blame] | 294 | return ipq_netlink_recvfrom(h, buf, len, timeout); |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 295 | } |
| 296 | |
| 297 | int ipq_message_type(const unsigned char *buf) |
| 298 | { |
| 299 | return ((struct nlmsghdr*)buf)->nlmsg_type; |
| 300 | } |
| 301 | |
| 302 | int ipq_get_msgerr(const unsigned char *buf) |
| 303 | { |
| 304 | struct nlmsghdr *h = (struct nlmsghdr *)buf; |
| 305 | struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| 306 | return -err->error; |
| 307 | } |
| 308 | |
| 309 | ipq_packet_msg_t *ipq_get_packet(const unsigned char *buf) |
| 310 | { |
| 311 | return NLMSG_DATA((struct nlmsghdr *)(buf)); |
| 312 | } |
| 313 | |
| 314 | int ipq_set_verdict(const struct ipq_handle *h, |
Rusty Russell | 803f33c | 2000-09-04 05:56:10 +0000 | [diff] [blame] | 315 | ipq_id_t id, |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 316 | unsigned int verdict, |
| 317 | size_t data_len, |
| 318 | unsigned char *buf) |
| 319 | { |
| 320 | unsigned char nvecs; |
| 321 | size_t tlen; |
| 322 | struct nlmsghdr nlh; |
| 323 | ipq_peer_msg_t pm; |
| 324 | struct iovec iov[3]; |
| 325 | struct msghdr msg; |
| 326 | |
| 327 | memset(&nlh, 0, sizeof(nlh)); |
| 328 | nlh.nlmsg_flags = NLM_F_REQUEST; |
| 329 | nlh.nlmsg_type = IPQM_VERDICT; |
| 330 | nlh.nlmsg_pid = h->local.nl_pid; |
| 331 | memset(&pm, 0, sizeof(pm)); |
| 332 | pm.msg.verdict.value = verdict; |
| 333 | pm.msg.verdict.id = id; |
| 334 | pm.msg.verdict.data_len = data_len; |
| 335 | iov[0].iov_base = &nlh; |
| 336 | iov[0].iov_len = sizeof(nlh); |
| 337 | iov[1].iov_base = ± |
| 338 | iov[1].iov_len = sizeof(pm); |
| 339 | tlen = sizeof(nlh) + sizeof(pm); |
| 340 | nvecs = 2; |
| 341 | if (data_len && buf) { |
| 342 | iov[2].iov_base = buf; |
| 343 | iov[2].iov_len = data_len; |
| 344 | tlen += data_len; |
| 345 | nvecs++; |
| 346 | } |
| 347 | msg.msg_name = (void *)&h->peer; |
| 348 | msg.msg_namelen = sizeof(h->peer); |
| 349 | msg.msg_iov = iov; |
| 350 | msg.msg_iovlen = nvecs; |
| 351 | msg.msg_control = NULL; |
| 352 | msg.msg_controllen = 0; |
| 353 | msg.msg_flags = 0; |
| 354 | nlh.nlmsg_len = tlen; |
| 355 | return ipq_netlink_sendmsg(h, &msg, 0); |
| 356 | } |
| 357 | |
| 358 | /* Not implemented yet */ |
| 359 | int ipq_ctl(const struct ipq_handle *h, int request, ...) |
| 360 | { |
| 361 | return 1; |
| 362 | } |
| 363 | |
James Morris | b1e0b99 | 2000-11-18 05:14:39 +0000 | [diff] [blame] | 364 | char *ipq_errstr(void) |
| 365 | { |
| 366 | return ipq_strerror(ipq_errno); |
| 367 | } |
| 368 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 369 | void ipq_perror(const char *s) |
| 370 | { |
| 371 | if (s) |
| 372 | fputs(s, stderr); |
| 373 | else |
| 374 | fputs("ERROR", stderr); |
| 375 | if (ipq_errno) |
James Morris | b1e0b99 | 2000-11-18 05:14:39 +0000 | [diff] [blame] | 376 | fprintf(stderr, ": %s", ipq_errstr()); |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 377 | if (errno) |
| 378 | fprintf(stderr, ": %s", strerror(errno)); |
| 379 | fputc('\n', stderr); |
| 380 | } |