lib/netfilter/queue_msg.c

   1 /*
   2  * lib/netfilter/queue_msg.c    Netfilter Queue Messages
   3  *
   4  *      This library is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU Lesser General Public
   6  *      License as published by the Free Software Foundation version 2.1
   7  *      of the License.
   8  *
   9  * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
  10  * Copyright (c) 2010       Karl Hiramoto <karl@hiramoto.org>
  11  */
  12
  13 /**
  14  * @ingroup nfnl
  15  * @defgroup queue Queue
  16  * @brief
  17  * @{
  18  */
  19
  20 #include <sys/types.h>
  21 #include <linux/netfilter/nfnetlink_queue.h>
  22
  23 #include <netlink-local.h>
  24 #include <netlink/attr.h>
  25 #include <netlink/netfilter/nfnl.h>
  26 #include <netlink/netfilter/queue_msg.h>
  27
  28 static struct nl_cache_ops nfnl_queue_msg_ops;
  29
  30 #if __BYTE_ORDER == __BIG_ENDIAN
  31 static uint64_t ntohll(uint64_t x)
  32 {
  33         return x;
  34 }
  35 #elif __BYTE_ORDER == __LITTLE_ENDIAN
  36 static uint64_t ntohll(uint64_t x)
  37 {
  38         return __bswap_64(x);
  39 }
  40 #endif
  41
  42 static struct nla_policy queue_policy[NFQA_MAX+1] = {
  43         [NFQA_PACKET_HDR]               = {
  44                 .minlen = sizeof(struct nfqnl_msg_packet_hdr),
  45         },
  46         [NFQA_VERDICT_HDR]              = {
  47                 .minlen = sizeof(struct nfqnl_msg_verdict_hdr),
  48         },
  49         [NFQA_MARK]                     = { .type = NLA_U32 },
  50         [NFQA_TIMESTAMP]                = {
  51                 .minlen = sizeof(struct nfqnl_msg_packet_timestamp),
  52         },
  53         [NFQA_IFINDEX_INDEV]            = { .type = NLA_U32 },
  54         [NFQA_IFINDEX_OUTDEV]           = { .type = NLA_U32 },
  55         [NFQA_IFINDEX_PHYSINDEV]        = { .type = NLA_U32 },
  56         [NFQA_IFINDEX_PHYSOUTDEV]       = { .type = NLA_U32 },
  57         [NFQA_HWADDR]                   = {
  58                 .minlen = sizeof(struct nfqnl_msg_packet_hw),
  59         },
  60 };
  61
  62 int nfnlmsg_queue_msg_parse(struct nlmsghdr *nlh,
  63                             struct nfnl_queue_msg **result)
  64 {
  65         struct nfnl_queue_msg *msg;
  66         struct nlattr *tb[NFQA_MAX+1];
  67         struct nlattr *attr;
  68         int err;
  69
  70         msg = nfnl_queue_msg_alloc();
  71         if (!msg)
  72                 return -NLE_NOMEM;
  73
  74         msg->ce_msgtype = nlh->nlmsg_type;
  75
  76         err = nlmsg_parse(nlh, sizeof(struct nfgenmsg), tb, NFQA_MAX,
  77                           queue_policy);
  78         if (err < 0)
  79                 goto errout;
  80
  81         nfnl_queue_msg_set_group(msg, nfnlmsg_res_id(nlh));
  82         nfnl_queue_msg_set_family(msg, nfnlmsg_family(nlh));
  83
  84         attr = tb[NFQA_PACKET_HDR];
  85         if (attr) {
  86                 struct nfqnl_msg_packet_hdr *hdr = nla_data(attr);
  87
  88                 nfnl_queue_msg_set_packetid(msg, ntohl(hdr->packet_id));
  89                 if (hdr->hw_protocol)
  90                         nfnl_queue_msg_set_hwproto(msg, hdr->hw_protocol);
  91                 nfnl_queue_msg_set_hook(msg, hdr->hook);
  92         }
  93
  94         attr = tb[NFQA_MARK];
  95         if (attr)
  96                 nfnl_queue_msg_set_mark(msg, ntohl(nla_get_u32(attr)));
  97
  98         attr = tb[NFQA_TIMESTAMP];
  99         if (attr) {
 100                 struct nfqnl_msg_packet_timestamp *timestamp = nla_data(attr);
 101                 struct timeval tv;
 102
 103                 tv.tv_sec = ntohll(timestamp->sec);
 104                 tv.tv_usec = ntohll(timestamp->usec);
 105                 nfnl_queue_msg_set_timestamp(msg, &tv);
 106         }
 107
 108         attr = tb[NFQA_IFINDEX_INDEV];
 109         if (attr)
 110                 nfnl_queue_msg_set_indev(msg, ntohl(nla_get_u32(attr)));
 111
 112         attr = tb[NFQA_IFINDEX_OUTDEV];
 113         if (attr)
 114                 nfnl_queue_msg_set_outdev(msg, ntohl(nla_get_u32(attr)));
 115
 116         attr = tb[NFQA_IFINDEX_PHYSINDEV];
 117         if (attr)
 118                 nfnl_queue_msg_set_physindev(msg, ntohl(nla_get_u32(attr)));
 119
 120         attr = tb[NFQA_IFINDEX_PHYSOUTDEV];
 121         if (attr)
 122                 nfnl_queue_msg_set_physoutdev(msg, ntohl(nla_get_u32(attr)));
 123
 124         attr = tb[NFQA_HWADDR];
 125         if (attr) {
 126                 struct nfqnl_msg_packet_hw *hw = nla_data(attr);
 127
 128                 nfnl_queue_msg_set_hwaddr(msg, hw->hw_addr,
 129                                           ntohs(hw->hw_addrlen));
 130         }
 131
 132         attr = tb[NFQA_PAYLOAD];
 133         if (attr) {
 134                 err = nfnl_queue_msg_set_payload(msg, nla_data(attr),
 135                                                  nla_len(attr));
 136                 if (err < 0)
 137                         goto errout;
 138         }
 139
 140         *result = msg;
 141         return 0;
 142
 143 errout:
 144         nfnl_queue_msg_put(msg);
 145         return err;
 146 }
 147
 148 static int queue_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
 149                             struct nlmsghdr *nlh, struct nl_parser_param *pp)
 150 {
 151         struct nfnl_queue_msg *msg;
 152         int err;
 153
 154         if ((err = nfnlmsg_queue_msg_parse(nlh, &msg)) < 0)
 155                 goto errout;
 156
 157         err = pp->pp_cb((struct nl_object *) msg, pp);
 158 errout:
 159         nfnl_queue_msg_put(msg);
 160         return err;
 161 }
 162
 163 /** @} */
 164
 165 struct nl_msg *nfnl_queue_msg_build_verdict(const struct nfnl_queue_msg *msg)
 166 {
 167         struct nl_msg *nlmsg;
 168         struct nfqnl_msg_verdict_hdr verdict;
 169
 170         nlmsg = nfnlmsg_alloc_simple(NFNL_SUBSYS_QUEUE, NFQNL_MSG_VERDICT, 0,
 171                                      nfnl_queue_msg_get_family(msg),
 172                                      nfnl_queue_msg_get_group(msg));
 173         if (nlmsg == NULL)
 174                 return NULL;
 175
 176         verdict.id = htonl(nfnl_queue_msg_get_packetid(msg));
 177         verdict.verdict = htonl(nfnl_queue_msg_get_verdict(msg));
 178         if (nla_put(nlmsg, NFQA_VERDICT_HDR, sizeof(verdict), &verdict) < 0)
 179                 goto nla_put_failure;
 180
 181         if (nfnl_queue_msg_test_mark(msg) &&
 182             nla_put_u32(nlmsg, NFQA_MARK,
 183                         ntohl(nfnl_queue_msg_get_mark(msg))) < 0)
 184                 goto nla_put_failure;
 185
 186         return nlmsg;
 187
 188 nla_put_failure:
 189         nlmsg_free(nlmsg);
 190         return NULL;
 191 }
 192
 193 /**
 194 * Send a message verdict/mark
 195 * @arg nlh            netlink messsage header
 196 * @arg msg            queue msg
 197 * @return 0 on OK or error code
 198 */
 199 int nfnl_queue_msg_send_verdict(struct nl_sock *nlh,
 200                                 const struct nfnl_queue_msg *msg)
 201 {
 202         struct nl_msg *nlmsg;
 203         int err;
 204
 205         nlmsg = nfnl_queue_msg_build_verdict(msg);
 206         if (nlmsg == NULL)
 207                 return -NLE_NOMEM;
 208
 209         err = nl_send_auto_complete(nlh, nlmsg);
 210         nlmsg_free(nlmsg);
 211         if (err < 0)
 212                 return err;
 213         return wait_for_ack(nlh);
 214 }
 215
 216 /**
 217 * Send a message verdict including the payload
 218 * @arg nlh            netlink messsage header
 219 * @arg msg            queue msg
 220 * @arg payload_data   packet payload data
 221 * @arg payload_len    payload length
 222 * @return 0 on OK or error code
 223 */
 224 int nfnl_queue_msg_send_verdict_payload(struct nl_sock *nlh,
 225                                 const struct nfnl_queue_msg *msg,
 226                                 const void *payload_data, unsigned payload_len)
 227 {
 228         struct nl_msg *nlmsg;
 229         int err;
 230         struct iovec iov[3];
 231         struct nlattr nla;
 232
 233         nlmsg = nfnl_queue_msg_build_verdict(msg);
 234         if (nlmsg == NULL)
 235                 return -NLE_NOMEM;
 236
 237         memset(iov, 0, sizeof(iov));
 238
 239         iov[0].iov_base = (void *) nlmsg_hdr(nlmsg);
 240         iov[0].iov_len = nlmsg_hdr(nlmsg)->nlmsg_len;
 241
 242         nla.nla_type = NFQA_PAYLOAD;
 243         nla.nla_len = payload_len + sizeof(nla);
 244         nlmsg_hdr(nlmsg)->nlmsg_len += nla.nla_len;
 245
 246         iov[1].iov_base = (void *) &nla;
 247         iov[1].iov_len = sizeof(nla);
 248
 249         iov[2].iov_base = (void *) payload_data;
 250         iov[2].iov_len = NLA_ALIGN(payload_len);
 251
 252         nl_auto_complete(nlh, nlmsg);
 253         err = nl_send_iovec(nlh, nlmsg, iov, 3);
 254
 255         nlmsg_free(nlmsg);
 256         if (err < 0)
 257                 return err;
 258         return wait_for_ack(nlh);
 259 }
 260
 261 #define NFNLMSG_QUEUE_TYPE(type) NFNLMSG_TYPE(NFNL_SUBSYS_QUEUE, (type))
 262 static struct nl_cache_ops nfnl_queue_msg_ops = {
 263         .co_name                = "netfilter/queue_msg",
 264         .co_hdrsize             = NFNL_HDRLEN,
 265         .co_msgtypes            = {
 266                 { NFNLMSG_QUEUE_TYPE(NFQNL_MSG_PACKET), NL_ACT_NEW, "new" },
 267                 END_OF_MSGTYPES_LIST,
 268         },
 269         .co_protocol            = NETLINK_NETFILTER,
 270         .co_msg_parser          = queue_msg_parser,
 271         .co_obj_ops             = &queue_msg_obj_ops,
 272 };
 273
 274 static void __init nfnl_msg_queue_init(void)
 275 {
 276         nl_cache_mngt_register(&nfnl_queue_msg_ops);
 277 }
 278
 279 static void __exit nfnl_queue_msg_exit(void)
 280 {
 281         nl_cache_mngt_unregister(&nfnl_queue_msg_ops);
 282 }
 283
 284 /** @} */