JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2011 Jakub Zawadzki |
| 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 | * |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 14 | * 3. The name of the author may not be used to endorse or promote |
| 15 | * products derived from this software without specific prior written |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 16 | * permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | #ifdef HAVE_CONFIG_H |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 32 | #include <config.h> |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 33 | #endif |
| 34 | |
| 35 | #include "pcap-int.h" |
| 36 | |
| 37 | #ifdef NEED_STRERROR_H |
| 38 | #include "strerror.h" |
| 39 | #endif |
| 40 | |
| 41 | #include <errno.h> |
| 42 | #include <stdlib.h> |
| 43 | #include <unistd.h> |
| 44 | #include <string.h> |
| 45 | #include <sys/socket.h> |
| 46 | #include <arpa/inet.h> |
| 47 | |
| 48 | #include <time.h> |
| 49 | #include <sys/time.h> |
| 50 | #include <netinet/in.h> |
| 51 | #include <linux/types.h> |
| 52 | |
| 53 | #include <linux/netlink.h> |
| 54 | #include <linux/netfilter.h> |
| 55 | #include <linux/netfilter/nfnetlink.h> |
| 56 | #include <linux/netfilter/nfnetlink_log.h> |
| 57 | #include <linux/netfilter/nfnetlink_queue.h> |
| 58 | |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 59 | /* NOTE: if your program drops privileges after pcap_activate() it WON'T work with nfqueue. |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 60 | * It took me quite some time to debug ;/ |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 61 | * |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 62 | * Sending any data to nfnetlink socket requires CAP_NET_ADMIN privileges, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 63 | * and in nfqueue we need to send verdict reply after recving packet. |
| 64 | * |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 65 | * In tcpdump you can disable dropping privileges with -Z root |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 66 | */ |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 67 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 68 | #include "pcap-netfilter-linux.h" |
| 69 | |
| 70 | #define HDR_LENGTH (NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct nfgenmsg)))) |
| 71 | |
| 72 | #define NFLOG_IFACE "nflog" |
| 73 | #define NFQUEUE_IFACE "nfqueue" |
| 74 | |
| 75 | typedef enum { OTHER = -1, NFLOG, NFQUEUE } nftype_t; |
| 76 | |
| 77 | /* |
| 78 | * Private data for capturing on Linux netfilter sockets. |
| 79 | */ |
| 80 | struct pcap_netfilter { |
| 81 | u_int packets_read; /* count of packets read with recvfrom() */ |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 82 | u_int packets_nobufs; /* ENOBUFS counter */ |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 83 | }; |
| 84 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 85 | static int nfqueue_send_verdict(const pcap_t *handle, uint16_t group_id, u_int32_t id, u_int32_t verdict); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 86 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 87 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 88 | static int |
| 89 | netfilter_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) |
| 90 | { |
| 91 | struct pcap_netfilter *handlep = handle->priv; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 92 | register u_char *bp, *ep; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 93 | int count = 0; |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 94 | ssize_t len; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 95 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 96 | /* |
| 97 | * Has "pcap_breakloop()" been called? |
| 98 | */ |
| 99 | if (handle->break_loop) { |
| 100 | /* |
| 101 | * Yes - clear the flag that indicates that it |
| 102 | * has, and return PCAP_ERROR_BREAK to indicate |
| 103 | * that we were told to break out of the loop. |
| 104 | */ |
| 105 | handle->break_loop = 0; |
| 106 | return PCAP_ERROR_BREAK; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 107 | } |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 108 | len = handle->cc; |
| 109 | if (len == 0) { |
| 110 | /* |
| 111 | * The buffer is empty; refill it. |
| 112 | * |
| 113 | * We ignore EINTR, as that might just be due to a signal |
| 114 | * being delivered - if the signal should interrupt the |
| 115 | * loop, the signal handler should call pcap_breakloop() |
| 116 | * to set handle->break_loop (we ignore it on other |
| 117 | * platforms as well). |
| 118 | */ |
| 119 | do { |
| 120 | len = recv(handle->fd, handle->buffer, handle->bufsize, 0); |
| 121 | if (handle->break_loop) { |
| 122 | handle->break_loop = 0; |
| 123 | return PCAP_ERROR_BREAK; |
| 124 | } |
| 125 | if (errno == ENOBUFS) |
| 126 | handlep->packets_nobufs++; |
| 127 | } while ((len == -1) && (errno == EINTR || errno == ENOBUFS)); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 128 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 129 | if (len < 0) { |
| 130 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 131 | PCAP_ERRBUF_SIZE, errno, "Can't receive packet"); |
| 132 | return PCAP_ERROR; |
| 133 | } |
| 134 | |
| 135 | bp = (unsigned char *)handle->buffer; |
| 136 | } else |
| 137 | bp = handle->bp; |
| 138 | ep = bp + len; |
| 139 | while (bp < ep) { |
| 140 | const struct nlmsghdr *nlh = (const struct nlmsghdr *) bp; |
| 141 | uint32_t msg_len; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 142 | nftype_t type = OTHER; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 143 | /* |
| 144 | * Has "pcap_breakloop()" been called? |
| 145 | * If so, return immediately - if we haven't read any |
| 146 | * packets, clear the flag and return PCAP_ERROR_BREAK |
| 147 | * to indicate that we were told to break out of the loop, |
| 148 | * otherwise leave the flag set, so that the *next* call |
| 149 | * will break out of the loop without having read any |
| 150 | * packets, and return the number of packets we've |
| 151 | * processed so far. |
| 152 | */ |
| 153 | if (handle->break_loop) { |
| 154 | handle->bp = bp; |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 155 | handle->cc = (int)(ep - bp); |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 156 | if (count == 0) { |
| 157 | handle->break_loop = 0; |
| 158 | return PCAP_ERROR_BREAK; |
| 159 | } else |
| 160 | return count; |
| 161 | } |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 162 | /* |
| 163 | * NLMSG_SPACE(0) might be signed or might be unsigned, |
| 164 | * depending on whether the kernel defines NLMSG_ALIGNTO |
| 165 | * as 4, which older kernels do, or as 4U, which newer |
| 166 | * kernels do. |
| 167 | * |
| 168 | * ep - bp is of type ptrdiff_t, which is signed. |
| 169 | * |
| 170 | * To squelch warnings, we cast both to size_t, which |
| 171 | * is unsigned; ep >= bp, so the cast is safe. |
| 172 | */ |
| 173 | if ((size_t)(ep - bp) < (size_t)NLMSG_SPACE(0)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 174 | /* |
| 175 | * There's less than one netlink message left |
| 176 | * in the buffer. Give up. |
| 177 | */ |
| 178 | break; |
| 179 | } |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 180 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 181 | if (nlh->nlmsg_len < sizeof(struct nlmsghdr) || (u_int)len < nlh->nlmsg_len) { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 182 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Message truncated: (got: %zd) (nlmsg_len: %u)", len, nlh->nlmsg_len); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 183 | return -1; |
| 184 | } |
| 185 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 186 | if (NFNL_SUBSYS_ID(nlh->nlmsg_type) == NFNL_SUBSYS_ULOG && |
| 187 | NFNL_MSG_TYPE(nlh->nlmsg_type) == NFULNL_MSG_PACKET) |
| 188 | type = NFLOG; |
| 189 | else if (NFNL_SUBSYS_ID(nlh->nlmsg_type) == NFNL_SUBSYS_QUEUE && |
| 190 | NFNL_MSG_TYPE(nlh->nlmsg_type) == NFQNL_MSG_PACKET) |
| 191 | type = NFQUEUE; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 192 | |
| 193 | if (type != OTHER) { |
| 194 | const unsigned char *payload = NULL; |
| 195 | struct pcap_pkthdr pkth; |
| 196 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 197 | const struct nfgenmsg *nfg = NULL; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 198 | int id = 0; |
| 199 | |
| 200 | if (handle->linktype != DLT_NFLOG) { |
| 201 | const struct nfattr *payload_attr = NULL; |
| 202 | |
| 203 | if (nlh->nlmsg_len < HDR_LENGTH) { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 204 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Malformed message: (nlmsg_len: %u)", nlh->nlmsg_len); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 205 | return -1; |
| 206 | } |
| 207 | |
| 208 | nfg = NLMSG_DATA(nlh); |
| 209 | if (nlh->nlmsg_len > HDR_LENGTH) { |
| 210 | struct nfattr *attr = NFM_NFA(nfg); |
| 211 | int attr_len = nlh->nlmsg_len - NLMSG_ALIGN(HDR_LENGTH); |
| 212 | |
| 213 | while (NFA_OK(attr, attr_len)) { |
| 214 | if (type == NFQUEUE) { |
| 215 | switch (NFA_TYPE(attr)) { |
| 216 | case NFQA_PACKET_HDR: |
| 217 | { |
| 218 | const struct nfqnl_msg_packet_hdr *pkt_hdr = (const struct nfqnl_msg_packet_hdr *) NFA_DATA(attr); |
| 219 | |
| 220 | id = ntohl(pkt_hdr->packet_id); |
| 221 | break; |
| 222 | } |
| 223 | case NFQA_PAYLOAD: |
| 224 | payload_attr = attr; |
| 225 | break; |
| 226 | } |
| 227 | |
| 228 | } else if (type == NFLOG) { |
| 229 | switch (NFA_TYPE(attr)) { |
| 230 | case NFULA_PAYLOAD: |
| 231 | payload_attr = attr; |
| 232 | break; |
| 233 | } |
| 234 | } |
| 235 | attr = NFA_NEXT(attr, attr_len); |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | if (payload_attr) { |
| 240 | payload = NFA_DATA(payload_attr); |
| 241 | pkth.len = pkth.caplen = NFA_PAYLOAD(payload_attr); |
| 242 | } |
| 243 | |
| 244 | } else { |
| 245 | payload = NLMSG_DATA(nlh); |
| 246 | pkth.caplen = pkth.len = nlh->nlmsg_len-NLMSG_ALIGN(sizeof(struct nlmsghdr)); |
| 247 | } |
| 248 | |
| 249 | if (payload) { |
| 250 | /* pkth.caplen = min (payload_len, handle->snapshot); */ |
| 251 | |
| 252 | gettimeofday(&pkth.ts, NULL); |
| 253 | if (handle->fcode.bf_insns == NULL || |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 254 | pcap_filter(handle->fcode.bf_insns, payload, pkth.len, pkth.caplen)) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 255 | { |
| 256 | handlep->packets_read++; |
| 257 | callback(user, &pkth, payload); |
| 258 | count++; |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | if (type == NFQUEUE) { |
| 263 | /* XXX, possible responses: NF_DROP, NF_ACCEPT, NF_STOLEN, NF_QUEUE, NF_REPEAT, NF_STOP */ |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 264 | /* if type == NFQUEUE, handle->linktype is always != DLT_NFLOG, |
| 265 | so nfg is always initialized to NLMSG_DATA(nlh). */ |
| 266 | if (nfg != NULL) |
| 267 | nfqueue_send_verdict(handle, ntohs(nfg->res_id), id, NF_ACCEPT); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 268 | } |
| 269 | } |
| 270 | |
| 271 | msg_len = NLMSG_ALIGN(nlh->nlmsg_len); |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 272 | /* |
| 273 | * If the message length would run past the end of the |
| 274 | * buffer, truncate it to the remaining space in the |
| 275 | * buffer. |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 276 | * |
| 277 | * To squelch warnings, we cast ep - bp to uint32_t, which |
| 278 | * is unsigned and is the type of msg_len; ep >= bp, and |
| 279 | * len should fit in 32 bits (either it's set from an int |
| 280 | * or it's set from a recv() call with a buffer size that's |
| 281 | * an int, and we're assuming either ILP32 or LP64), so |
| 282 | * the cast is safe. |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 283 | */ |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 284 | if (msg_len > (uint32_t)(ep - bp)) |
| 285 | msg_len = (uint32_t)(ep - bp); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 286 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 287 | bp += msg_len; |
| 288 | if (count >= max_packets && !PACKET_COUNT_IS_UNLIMITED(max_packets)) { |
| 289 | handle->bp = bp; |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 290 | handle->cc = (int)(ep - bp); |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 291 | if (handle->cc < 0) |
| 292 | handle->cc = 0; |
| 293 | return count; |
| 294 | } |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 295 | } |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 296 | |
| 297 | handle->cc = 0; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 298 | return count; |
| 299 | } |
| 300 | |
| 301 | static int |
| 302 | netfilter_set_datalink(pcap_t *handle, int dlt) |
| 303 | { |
| 304 | handle->linktype = dlt; |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | static int |
| 309 | netfilter_stats_linux(pcap_t *handle, struct pcap_stat *stats) |
| 310 | { |
| 311 | struct pcap_netfilter *handlep = handle->priv; |
| 312 | |
| 313 | stats->ps_recv = handlep->packets_read; |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 314 | stats->ps_drop = handlep->packets_nobufs; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 315 | stats->ps_ifdrop = 0; |
| 316 | return 0; |
| 317 | } |
| 318 | |
| 319 | static int |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 320 | netfilter_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 321 | { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 322 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
Haibo Huang | 4ccd683 | 2020-04-23 18:03:48 -0700 | [diff] [blame] | 323 | "Packet injection is not supported on netfilter devices"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 324 | return (-1); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 325 | } |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 326 | |
| 327 | struct my_nfattr { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 328 | uint16_t nfa_len; |
| 329 | uint16_t nfa_type; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 330 | void *data; |
| 331 | }; |
| 332 | |
| 333 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 334 | netfilter_send_config_msg(const pcap_t *handle, uint16_t msg_type, int ack, u_int8_t family, u_int16_t res_id, const struct my_nfattr *mynfa) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 335 | { |
| 336 | char buf[1024] __attribute__ ((aligned)); |
Haibo Huang | 4ccd683 | 2020-04-23 18:03:48 -0700 | [diff] [blame] | 337 | memset(buf, 0, sizeof(buf)); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 338 | |
| 339 | struct nlmsghdr *nlh = (struct nlmsghdr *) buf; |
| 340 | struct nfgenmsg *nfg = (struct nfgenmsg *) (buf + sizeof(struct nlmsghdr)); |
| 341 | |
| 342 | struct sockaddr_nl snl; |
| 343 | static unsigned int seq_id; |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 344 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 345 | if (!seq_id) |
| 346 | seq_id = time(NULL); |
| 347 | ++seq_id; |
| 348 | |
| 349 | nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nfgenmsg)); |
| 350 | nlh->nlmsg_type = msg_type; |
| 351 | nlh->nlmsg_flags = NLM_F_REQUEST | (ack ? NLM_F_ACK : 0); |
| 352 | nlh->nlmsg_pid = 0; /* to kernel */ |
| 353 | nlh->nlmsg_seq = seq_id; |
| 354 | |
| 355 | nfg->nfgen_family = family; |
| 356 | nfg->version = NFNETLINK_V0; |
| 357 | nfg->res_id = htons(res_id); |
| 358 | |
| 359 | if (mynfa) { |
| 360 | struct nfattr *nfa = (struct nfattr *) (buf + NLMSG_ALIGN(nlh->nlmsg_len)); |
| 361 | |
| 362 | nfa->nfa_type = mynfa->nfa_type; |
| 363 | nfa->nfa_len = NFA_LENGTH(mynfa->nfa_len); |
| 364 | memcpy(NFA_DATA(nfa), mynfa->data, mynfa->nfa_len); |
| 365 | nlh->nlmsg_len = NLMSG_ALIGN(nlh->nlmsg_len) + NFA_ALIGN(nfa->nfa_len); |
| 366 | } |
| 367 | |
| 368 | memset(&snl, 0, sizeof(snl)); |
| 369 | snl.nl_family = AF_NETLINK; |
| 370 | |
| 371 | if (sendto(handle->fd, nlh, nlh->nlmsg_len, 0, (struct sockaddr *) &snl, sizeof(snl)) == -1) |
| 372 | return -1; |
| 373 | |
| 374 | if (!ack) |
| 375 | return 0; |
| 376 | |
| 377 | /* waiting for reply loop */ |
| 378 | do { |
| 379 | socklen_t addrlen = sizeof(snl); |
| 380 | int len; |
| 381 | |
| 382 | /* ignore interrupt system call error */ |
| 383 | do { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 384 | /* |
| 385 | * The buffer is not so big that its size won't |
| 386 | * fit into an int. |
| 387 | */ |
| 388 | len = (int)recvfrom(handle->fd, buf, sizeof(buf), 0, (struct sockaddr *) &snl, &addrlen); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 389 | } while ((len == -1) && (errno == EINTR)); |
| 390 | |
| 391 | if (len <= 0) |
| 392 | return len; |
| 393 | |
| 394 | if (addrlen != sizeof(snl) || snl.nl_family != AF_NETLINK) { |
| 395 | errno = EINVAL; |
| 396 | return -1; |
| 397 | } |
| 398 | |
| 399 | nlh = (struct nlmsghdr *) buf; |
| 400 | if (snl.nl_pid != 0 || seq_id != nlh->nlmsg_seq) /* if not from kernel or wrong sequence skip */ |
| 401 | continue; |
| 402 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 403 | while ((u_int)len >= NLMSG_SPACE(0) && NLMSG_OK(nlh, (u_int)len)) { |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 404 | if (nlh->nlmsg_type == NLMSG_ERROR || (nlh->nlmsg_type == NLMSG_DONE && nlh->nlmsg_flags & NLM_F_MULTI)) { |
| 405 | if (nlh->nlmsg_len < NLMSG_ALIGN(sizeof(struct nlmsgerr))) { |
| 406 | errno = EBADMSG; |
| 407 | return -1; |
| 408 | } |
| 409 | errno = -(*((int *)NLMSG_DATA(nlh))); |
| 410 | return (errno == 0) ? 0 : -1; |
| 411 | } |
| 412 | nlh = NLMSG_NEXT(nlh, len); |
| 413 | } |
| 414 | } while (1); |
| 415 | |
| 416 | return -1; /* never here */ |
| 417 | } |
| 418 | |
| 419 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 420 | nflog_send_config_msg(const pcap_t *handle, uint8_t family, u_int16_t group_id, const struct my_nfattr *mynfa) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 421 | { |
| 422 | return netfilter_send_config_msg(handle, (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG, 1, family, group_id, mynfa); |
| 423 | } |
| 424 | |
| 425 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 426 | nflog_send_config_cmd(const pcap_t *handle, uint16_t group_id, u_int8_t cmd, u_int8_t family) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 427 | { |
| 428 | struct nfulnl_msg_config_cmd msg; |
| 429 | struct my_nfattr nfa; |
| 430 | |
| 431 | msg.command = cmd; |
| 432 | |
| 433 | nfa.data = &msg; |
| 434 | nfa.nfa_type = NFULA_CFG_CMD; |
| 435 | nfa.nfa_len = sizeof(msg); |
| 436 | |
| 437 | return nflog_send_config_msg(handle, family, group_id, &nfa); |
| 438 | } |
| 439 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 440 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 441 | nflog_send_config_mode(const pcap_t *handle, uint16_t group_id, u_int8_t copy_mode, u_int32_t copy_range) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 442 | { |
| 443 | struct nfulnl_msg_config_mode msg; |
| 444 | struct my_nfattr nfa; |
| 445 | |
| 446 | msg.copy_range = htonl(copy_range); |
| 447 | msg.copy_mode = copy_mode; |
| 448 | |
| 449 | nfa.data = &msg; |
| 450 | nfa.nfa_type = NFULA_CFG_MODE; |
| 451 | nfa.nfa_len = sizeof(msg); |
| 452 | |
| 453 | return nflog_send_config_msg(handle, AF_UNSPEC, group_id, &nfa); |
| 454 | } |
| 455 | |
| 456 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 457 | nfqueue_send_verdict(const pcap_t *handle, uint16_t group_id, u_int32_t id, u_int32_t verdict) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 458 | { |
| 459 | struct nfqnl_msg_verdict_hdr msg; |
| 460 | struct my_nfattr nfa; |
| 461 | |
| 462 | msg.id = htonl(id); |
| 463 | msg.verdict = htonl(verdict); |
| 464 | |
| 465 | nfa.data = &msg; |
| 466 | nfa.nfa_type = NFQA_VERDICT_HDR; |
| 467 | nfa.nfa_len = sizeof(msg); |
| 468 | |
| 469 | return netfilter_send_config_msg(handle, (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_VERDICT, 0, AF_UNSPEC, group_id, &nfa); |
| 470 | } |
| 471 | |
| 472 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 473 | nfqueue_send_config_msg(const pcap_t *handle, uint8_t family, u_int16_t group_id, const struct my_nfattr *mynfa) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 474 | { |
| 475 | return netfilter_send_config_msg(handle, (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG, 1, family, group_id, mynfa); |
| 476 | } |
| 477 | |
| 478 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 479 | nfqueue_send_config_cmd(const pcap_t *handle, uint16_t group_id, u_int8_t cmd, u_int16_t pf) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 480 | { |
| 481 | struct nfqnl_msg_config_cmd msg; |
| 482 | struct my_nfattr nfa; |
| 483 | |
| 484 | msg.command = cmd; |
| 485 | msg.pf = htons(pf); |
| 486 | |
| 487 | nfa.data = &msg; |
| 488 | nfa.nfa_type = NFQA_CFG_CMD; |
| 489 | nfa.nfa_len = sizeof(msg); |
| 490 | |
| 491 | return nfqueue_send_config_msg(handle, AF_UNSPEC, group_id, &nfa); |
| 492 | } |
| 493 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 494 | static int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 495 | nfqueue_send_config_mode(const pcap_t *handle, uint16_t group_id, u_int8_t copy_mode, u_int32_t copy_range) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 496 | { |
| 497 | struct nfqnl_msg_config_params msg; |
| 498 | struct my_nfattr nfa; |
| 499 | |
| 500 | msg.copy_range = htonl(copy_range); |
| 501 | msg.copy_mode = copy_mode; |
| 502 | |
| 503 | nfa.data = &msg; |
| 504 | nfa.nfa_type = NFQA_CFG_PARAMS; |
| 505 | nfa.nfa_len = sizeof(msg); |
| 506 | |
| 507 | return nfqueue_send_config_msg(handle, AF_UNSPEC, group_id, &nfa); |
| 508 | } |
| 509 | |
| 510 | static int |
| 511 | netfilter_activate(pcap_t* handle) |
| 512 | { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 513 | const char *dev = handle->opt.device; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 514 | unsigned short groups[32]; |
| 515 | int group_count = 0; |
| 516 | nftype_t type = OTHER; |
| 517 | int i; |
| 518 | |
| 519 | if (strncmp(dev, NFLOG_IFACE, strlen(NFLOG_IFACE)) == 0) { |
| 520 | dev += strlen(NFLOG_IFACE); |
| 521 | type = NFLOG; |
| 522 | |
| 523 | } else if (strncmp(dev, NFQUEUE_IFACE, strlen(NFQUEUE_IFACE)) == 0) { |
| 524 | dev += strlen(NFQUEUE_IFACE); |
| 525 | type = NFQUEUE; |
| 526 | } |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 527 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 528 | if (type != OTHER && *dev == ':') { |
| 529 | dev++; |
| 530 | while (*dev) { |
| 531 | long int group_id; |
| 532 | char *end_dev; |
| 533 | |
| 534 | if (group_count == 32) { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 535 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 536 | "Maximum 32 netfilter groups! dev: %s", |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 537 | handle->opt.device); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 538 | return PCAP_ERROR; |
| 539 | } |
| 540 | |
| 541 | group_id = strtol(dev, &end_dev, 0); |
| 542 | if (end_dev != dev) { |
| 543 | if (group_id < 0 || group_id > 65535) { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 544 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 545 | "Netfilter group range from 0 to 65535 (got %ld)", |
| 546 | group_id); |
| 547 | return PCAP_ERROR; |
| 548 | } |
| 549 | |
| 550 | groups[group_count++] = (unsigned short) group_id; |
| 551 | dev = end_dev; |
| 552 | } |
| 553 | if (*dev != ',') |
| 554 | break; |
| 555 | dev++; |
| 556 | } |
| 557 | } |
| 558 | |
| 559 | if (type == OTHER || *dev) { |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 560 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 561 | "Can't get netfilter group(s) index from %s", |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 562 | handle->opt.device); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 563 | return PCAP_ERROR; |
| 564 | } |
| 565 | |
| 566 | /* if no groups, add default: 0 */ |
| 567 | if (!group_count) { |
| 568 | groups[0] = 0; |
| 569 | group_count = 1; |
| 570 | } |
| 571 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 572 | /* |
| 573 | * Turn a negative snapshot value (invalid), a snapshot value of |
| 574 | * 0 (unspecified), or a value bigger than the normal maximum |
| 575 | * value, into the maximum allowed value. |
| 576 | * |
| 577 | * If some application really *needs* a bigger snapshot |
| 578 | * length, we should just increase MAXIMUM_SNAPLEN. |
| 579 | */ |
| 580 | if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) |
| 581 | handle->snapshot = MAXIMUM_SNAPLEN; |
| 582 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 583 | /* Initialize some components of the pcap structure. */ |
| 584 | handle->bufsize = 128 + handle->snapshot; |
| 585 | handle->offset = 0; |
| 586 | handle->read_op = netfilter_read_linux; |
| 587 | handle->inject_op = netfilter_inject_linux; |
| 588 | handle->setfilter_op = install_bpf_program; /* no kernel filtering */ |
| 589 | handle->setdirection_op = NULL; |
| 590 | handle->set_datalink_op = netfilter_set_datalink; |
| 591 | handle->getnonblock_op = pcap_getnonblock_fd; |
| 592 | handle->setnonblock_op = pcap_setnonblock_fd; |
| 593 | handle->stats_op = netfilter_stats_linux; |
| 594 | |
| 595 | /* Create netlink socket */ |
| 596 | handle->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER); |
| 597 | if (handle->fd < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 598 | pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, |
| 599 | errno, "Can't create raw socket"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 600 | return PCAP_ERROR; |
| 601 | } |
| 602 | |
| 603 | if (type == NFLOG) { |
| 604 | handle->linktype = DLT_NFLOG; |
| 605 | handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); |
| 606 | if (handle->dlt_list != NULL) { |
| 607 | handle->dlt_list[0] = DLT_NFLOG; |
| 608 | handle->dlt_list[1] = DLT_IPV4; |
| 609 | handle->dlt_count = 2; |
| 610 | } |
| 611 | |
| 612 | } else |
| 613 | handle->linktype = DLT_IPV4; |
| 614 | |
| 615 | handle->buffer = malloc(handle->bufsize); |
| 616 | if (!handle->buffer) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 617 | pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, |
| 618 | errno, "Can't allocate dump buffer"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 619 | goto close_fail; |
| 620 | } |
| 621 | |
| 622 | if (type == NFLOG) { |
| 623 | if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 624 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 625 | PCAP_ERRBUF_SIZE, errno, |
| 626 | "NFULNL_CFG_CMD_PF_UNBIND"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 627 | goto close_fail; |
| 628 | } |
| 629 | |
| 630 | if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_BIND, AF_INET) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 631 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 632 | PCAP_ERRBUF_SIZE, errno, "NFULNL_CFG_CMD_PF_BIND"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 633 | goto close_fail; |
| 634 | } |
| 635 | |
| 636 | /* Bind socket to the nflog groups */ |
| 637 | for (i = 0; i < group_count; i++) { |
| 638 | if (nflog_send_config_cmd(handle, groups[i], NFULNL_CFG_CMD_BIND, AF_UNSPEC) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 639 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 640 | PCAP_ERRBUF_SIZE, errno, |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 641 | "Can't listen on group index"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 642 | goto close_fail; |
| 643 | } |
| 644 | |
| 645 | if (nflog_send_config_mode(handle, groups[i], NFULNL_COPY_PACKET, handle->snapshot) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 646 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 647 | PCAP_ERRBUF_SIZE, errno, |
| 648 | "NFULNL_COPY_PACKET"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 649 | goto close_fail; |
| 650 | } |
| 651 | } |
| 652 | |
| 653 | } else { |
| 654 | if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 655 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 656 | PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_UNBIND"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 657 | goto close_fail; |
| 658 | } |
| 659 | |
| 660 | if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_BIND, AF_INET) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 661 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 662 | PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_BIND"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 663 | goto close_fail; |
| 664 | } |
| 665 | |
| 666 | /* Bind socket to the nfqueue groups */ |
| 667 | for (i = 0; i < group_count; i++) { |
| 668 | if (nfqueue_send_config_cmd(handle, groups[i], NFQNL_CFG_CMD_BIND, AF_UNSPEC) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 669 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 670 | PCAP_ERRBUF_SIZE, errno, |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 671 | "Can't listen on group index"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 672 | goto close_fail; |
| 673 | } |
| 674 | |
| 675 | if (nfqueue_send_config_mode(handle, groups[i], NFQNL_COPY_PACKET, handle->snapshot) < 0) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 676 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 677 | PCAP_ERRBUF_SIZE, errno, |
| 678 | "NFQNL_COPY_PACKET"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 679 | goto close_fail; |
| 680 | } |
| 681 | } |
| 682 | } |
| 683 | |
| 684 | if (handle->opt.rfmon) { |
| 685 | /* |
| 686 | * Monitor mode doesn't apply to netfilter devices. |
| 687 | */ |
| 688 | pcap_cleanup_live_common(handle); |
| 689 | return PCAP_ERROR_RFMON_NOTSUP; |
| 690 | } |
| 691 | |
| 692 | if (handle->opt.buffer_size != 0) { |
| 693 | /* |
| 694 | * Set the socket buffer size to the specified value. |
| 695 | */ |
| 696 | if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, &handle->opt.buffer_size, sizeof(handle->opt.buffer_size)) == -1) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 697 | pcap_fmt_errmsg_for_errno(handle->errbuf, |
| 698 | PCAP_ERRBUF_SIZE, errno, "SO_RCVBUF"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 699 | goto close_fail; |
| 700 | } |
| 701 | } |
| 702 | |
| 703 | handle->selectable_fd = handle->fd; |
| 704 | return 0; |
| 705 | |
| 706 | close_fail: |
| 707 | pcap_cleanup_live_common(handle); |
| 708 | return PCAP_ERROR; |
| 709 | } |
| 710 | |
| 711 | pcap_t * |
| 712 | netfilter_create(const char *device, char *ebuf, int *is_ours) |
| 713 | { |
| 714 | const char *cp; |
| 715 | pcap_t *p; |
| 716 | |
| 717 | /* Does this look like an netfilter device? */ |
| 718 | cp = strrchr(device, '/'); |
| 719 | if (cp == NULL) |
| 720 | cp = device; |
| 721 | |
| 722 | /* Does it begin with NFLOG_IFACE or NFQUEUE_IFACE? */ |
| 723 | if (strncmp(cp, NFLOG_IFACE, sizeof NFLOG_IFACE - 1) == 0) |
| 724 | cp += sizeof NFLOG_IFACE - 1; |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 725 | else if (strncmp(cp, NFQUEUE_IFACE, sizeof NFQUEUE_IFACE - 1) == 0) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 726 | cp += sizeof NFQUEUE_IFACE - 1; |
| 727 | else { |
| 728 | /* Nope, doesn't begin with NFLOG_IFACE nor NFQUEUE_IFACE */ |
| 729 | *is_ours = 0; |
| 730 | return NULL; |
| 731 | } |
| 732 | |
| 733 | /* |
| 734 | * Yes - is that either the end of the name, or is it followed |
| 735 | * by a colon? |
| 736 | */ |
| 737 | if (*cp != ':' && *cp != '\0') { |
| 738 | /* Nope */ |
| 739 | *is_ours = 0; |
| 740 | return NULL; |
| 741 | } |
| 742 | |
| 743 | /* OK, it's probably ours. */ |
| 744 | *is_ours = 1; |
| 745 | |
Haibo Huang | ee759ce | 2021-01-05 21:34:29 -0800 | [diff] [blame] | 746 | p = PCAP_CREATE_COMMON(ebuf, struct pcap_netfilter); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 747 | if (p == NULL) |
| 748 | return (NULL); |
| 749 | |
| 750 | p->activate_op = netfilter_activate; |
| 751 | return (p); |
| 752 | } |
| 753 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 754 | int |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 755 | netfilter_findalldevs(pcap_if_list_t *devlistp, char *err_str) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 756 | { |
| 757 | int sock; |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 758 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 759 | sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER); |
| 760 | if (sock < 0) { |
| 761 | /* if netlink is not supported this is not fatal */ |
| 762 | if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) |
| 763 | return 0; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 764 | pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, |
| 765 | errno, "Can't open netlink socket"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 766 | return -1; |
| 767 | } |
| 768 | close(sock); |
| 769 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 770 | /* |
| 771 | * The notion of "connected" vs. "disconnected" doesn't apply. |
| 772 | * XXX - what about "up" and "running"? |
| 773 | */ |
| 774 | if (add_dev(devlistp, NFLOG_IFACE, |
| 775 | PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE, |
| 776 | "Linux netfilter log (NFLOG) interface", err_str) == NULL) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 777 | return -1; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 778 | if (add_dev(devlistp, NFQUEUE_IFACE, |
| 779 | PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE, |
| 780 | "Linux netfilter queue (NFQUEUE) interface", err_str) == NULL) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 781 | return -1; |
| 782 | return 0; |
| 783 | } |