queue_msg.c

00001 /*
00002  * lib/netfilter/queue_msg.c    Netfilter Queue Messages
00003  *
00004  *      This library is free software; you can redistribute it and/or
00005  *      modify it under the terms of the GNU Lesser General Public
00006  *      License as published by the Free Software Foundation version 2.1
00007  *      of the License.
00008  *
00009  * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
00010  * Copyright (c) 2010       Karl Hiramoto <karl@hiramoto.org>
00011  */
00012 
00013 /**
00014  * @ingroup nfnl
00015  * @defgroup queue Queue
00016  * @brief
00017  * @{
00018  */
00019 
00020 #include <sys/types.h>
00021 #include <linux/netfilter/nfnetlink_queue.h>
00022 
00023 #include <netlink-local.h>
00024 #include <netlink/attr.h>
00025 #include <netlink/netfilter/nfnl.h>
00026 #include <netlink/netfilter/queue_msg.h>
00027 
00028 static struct nl_cache_ops nfnl_queue_msg_ops;
00029 
00030 #if __BYTE_ORDER == __BIG_ENDIAN
00031 static uint64_t ntohll(uint64_t x)
00032 {
00033         return x;
00034 }
00035 #elif __BYTE_ORDER == __LITTLE_ENDIAN
00036 static uint64_t ntohll(uint64_t x)
00037 {
00038         return __bswap_64(x);
00039 }
00040 #endif
00041 
00042 static struct nla_policy queue_policy[NFQA_MAX+1] = {
00043         [NFQA_PACKET_HDR]               = {
00044                 .minlen = sizeof(struct nfqnl_msg_packet_hdr),
00045         },
00046         [NFQA_VERDICT_HDR]              = {
00047                 .minlen = sizeof(struct nfqnl_msg_verdict_hdr),
00048         },
00049         [NFQA_MARK]                     = { .type = NLA_U32 },
00050         [NFQA_TIMESTAMP]                = {
00051                 .minlen = sizeof(struct nfqnl_msg_packet_timestamp),
00052         },
00053         [NFQA_IFINDEX_INDEV]            = { .type = NLA_U32 },
00054         [NFQA_IFINDEX_OUTDEV]           = { .type = NLA_U32 },
00055         [NFQA_IFINDEX_PHYSINDEV]        = { .type = NLA_U32 },
00056         [NFQA_IFINDEX_PHYSOUTDEV]       = { .type = NLA_U32 },
00057         [NFQA_HWADDR]                   = {
00058                 .minlen = sizeof(struct nfqnl_msg_packet_hw),
00059         },
00060 };
00061 
00062 int nfnlmsg_queue_msg_parse(struct nlmsghdr *nlh,
00063                             struct nfnl_queue_msg **result)
00064 {
00065         struct nfnl_queue_msg *msg;
00066         struct nlattr *tb[NFQA_MAX+1];
00067         struct nlattr *attr;
00068         int err;
00069 
00070         msg = nfnl_queue_msg_alloc();
00071         if (!msg)
00072                 return -NLE_NOMEM;
00073 
00074         msg->ce_msgtype = nlh->nlmsg_type;
00075 
00076         err = nlmsg_parse(nlh, sizeof(struct nfgenmsg), tb, NFQA_MAX,
00077                           queue_policy);
00078         if (err < 0)
00079                 goto errout;
00080 
00081         nfnl_queue_msg_set_group(msg, nfnlmsg_res_id(nlh));
00082         nfnl_queue_msg_set_family(msg, nfnlmsg_family(nlh));
00083 
00084         attr = tb[NFQA_PACKET_HDR];
00085         if (attr) {
00086                 struct nfqnl_msg_packet_hdr *hdr = nla_data(attr);
00087 
00088                 nfnl_queue_msg_set_packetid(msg, ntohl(hdr->packet_id));
00089                 if (hdr->hw_protocol)
00090                         nfnl_queue_msg_set_hwproto(msg, hdr->hw_protocol);
00091                 nfnl_queue_msg_set_hook(msg, hdr->hook);
00092         }
00093 
00094         attr = tb[NFQA_MARK];
00095         if (attr)
00096                 nfnl_queue_msg_set_mark(msg, ntohl(nla_get_u32(attr)));
00097 
00098         attr = tb[NFQA_TIMESTAMP];
00099         if (attr) {
00100                 struct nfqnl_msg_packet_timestamp *timestamp = nla_data(attr);
00101                 struct timeval tv;
00102 
00103                 tv.tv_sec = ntohll(timestamp->sec);
00104                 tv.tv_usec = ntohll(timestamp->usec);
00105                 nfnl_queue_msg_set_timestamp(msg, &tv);
00106         }
00107 
00108         attr = tb[NFQA_IFINDEX_INDEV];
00109         if (attr)
00110                 nfnl_queue_msg_set_indev(msg, ntohl(nla_get_u32(attr)));
00111 
00112         attr = tb[NFQA_IFINDEX_OUTDEV];
00113         if (attr)
00114                 nfnl_queue_msg_set_outdev(msg, ntohl(nla_get_u32(attr)));
00115 
00116         attr = tb[NFQA_IFINDEX_PHYSINDEV];
00117         if (attr)
00118                 nfnl_queue_msg_set_physindev(msg, ntohl(nla_get_u32(attr)));
00119 
00120         attr = tb[NFQA_IFINDEX_PHYSOUTDEV];
00121         if (attr)
00122                 nfnl_queue_msg_set_physoutdev(msg, ntohl(nla_get_u32(attr)));
00123 
00124         attr = tb[NFQA_HWADDR];
00125         if (attr) {
00126                 struct nfqnl_msg_packet_hw *hw = nla_data(attr);
00127 
00128                 nfnl_queue_msg_set_hwaddr(msg, hw->hw_addr,
00129                                           ntohs(hw->hw_addrlen));
00130         }
00131 
00132         attr = tb[NFQA_PAYLOAD];
00133         if (attr) {
00134                 err = nfnl_queue_msg_set_payload(msg, nla_data(attr),
00135                                                  nla_len(attr));
00136                 if (err < 0)
00137                         goto errout;
00138         }
00139 
00140         *result = msg;
00141         return 0;
00142 
00143 errout:
00144         nfnl_queue_msg_put(msg);
00145         return err;
00146 }
00147 
00148 static int queue_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
00149                             struct nlmsghdr *nlh, struct nl_parser_param *pp)
00150 {
00151         struct nfnl_queue_msg *msg;
00152         int err;
00153 
00154         if ((err = nfnlmsg_queue_msg_parse(nlh, &msg)) < 0)
00155                 goto errout;
00156 
00157         err = pp->pp_cb((struct nl_object *) msg, pp);
00158 errout:
00159         nfnl_queue_msg_put(msg);
00160         return err;
00161 }
00162 
00163 /** @} */
00164 
00165 struct nl_msg *nfnl_queue_msg_build_verdict(const struct nfnl_queue_msg *msg)
00166 {
00167         struct nl_msg *nlmsg;
00168         struct nfqnl_msg_verdict_hdr verdict;
00169 
00170         nlmsg = nfnlmsg_alloc_simple(NFNL_SUBSYS_QUEUE, NFQNL_MSG_VERDICT, 0,
00171                                      nfnl_queue_msg_get_family(msg),
00172                                      nfnl_queue_msg_get_group(msg));
00173         if (nlmsg == NULL)
00174                 return NULL;
00175 
00176         verdict.id = htonl(nfnl_queue_msg_get_packetid(msg));
00177         verdict.verdict = htonl(nfnl_queue_msg_get_verdict(msg));
00178         if (nla_put(nlmsg, NFQA_VERDICT_HDR, sizeof(verdict), &verdict) < 0)
00179                 goto nla_put_failure;
00180 
00181         if (nfnl_queue_msg_test_mark(msg) &&
00182             nla_put_u32(nlmsg, NFQA_MARK,
00183                         ntohl(nfnl_queue_msg_get_mark(msg))) < 0)
00184                 goto nla_put_failure;
00185 
00186         return nlmsg;
00187 
00188 nla_put_failure:
00189         nlmsg_free(nlmsg);
00190         return NULL;
00191 }
00192 
00193 /**
00194 * Send a message verdict/mark
00195 * @arg nlh            netlink messsage header
00196 * @arg msg            queue msg
00197 * @return 0 on OK or error code
00198 */
00199 int nfnl_queue_msg_send_verdict(struct nl_sock *nlh,
00200                                 const struct nfnl_queue_msg *msg)
00201 {
00202         struct nl_msg *nlmsg;
00203         int err;
00204 
00205         nlmsg = nfnl_queue_msg_build_verdict(msg);
00206         if (nlmsg == NULL)
00207                 return -NLE_NOMEM;
00208 
00209         err = nl_send_auto_complete(nlh, nlmsg);
00210         nlmsg_free(nlmsg);
00211         if (err < 0)
00212                 return err;
00213         return wait_for_ack(nlh);
00214 }
00215 
00216 /**
00217 * Send a message verdict including the payload
00218 * @arg nlh            netlink messsage header
00219 * @arg msg            queue msg
00220 * @arg payload_data   packet payload data
00221 * @arg payload_len    payload length
00222 * @return 0 on OK or error code
00223 */
00224 int nfnl_queue_msg_send_verdict_payload(struct nl_sock *nlh,
00225                                 const struct nfnl_queue_msg *msg,
00226                                 const void *payload_data, unsigned payload_len)
00227 {
00228         struct nl_msg *nlmsg;
00229         int err;
00230         struct iovec iov[3];
00231         struct nlattr nla;
00232 
00233         nlmsg = nfnl_queue_msg_build_verdict(msg);
00234         if (nlmsg == NULL)
00235                 return -NLE_NOMEM;
00236 
00237         memset(iov, 0, sizeof(iov));
00238 
00239         iov[0].iov_base = (void *) nlmsg_hdr(nlmsg);
00240         iov[0].iov_len = nlmsg_hdr(nlmsg)->nlmsg_len;
00241 
00242         nla.nla_type = NFQA_PAYLOAD;
00243         nla.nla_len = payload_len + sizeof(nla);
00244         nlmsg_hdr(nlmsg)->nlmsg_len += nla.nla_len;
00245 
00246         iov[1].iov_base = (void *) &nla;
00247         iov[1].iov_len = sizeof(nla);
00248 
00249         iov[2].iov_base = (void *) payload_data;
00250         iov[2].iov_len = NLA_ALIGN(payload_len);
00251 
00252         nl_complete_msg(nlh, nlmsg);
00253         err = nl_send_iovec(nlh, nlmsg, iov, 3);
00254 
00255         nlmsg_free(nlmsg);
00256         if (err < 0)
00257                 return err;
00258         return wait_for_ack(nlh);
00259 }
00260 
00261 #define NFNLMSG_QUEUE_TYPE(type) NFNLMSG_TYPE(NFNL_SUBSYS_QUEUE, (type))
00262 static struct nl_cache_ops nfnl_queue_msg_ops = {
00263         .co_name                = "netfilter/queue_msg",
00264         .co_hdrsize             = NFNL_HDRLEN,
00265         .co_msgtypes            = {
00266                 { NFNLMSG_QUEUE_TYPE(NFQNL_MSG_PACKET), NL_ACT_NEW, "new" },
00267                 END_OF_MSGTYPES_LIST,
00268         },
00269         .co_protocol            = NETLINK_NETFILTER,
00270         .co_msg_parser          = queue_msg_parser,
00271         .co_obj_ops             = &queue_msg_obj_ops,
00272 };
00273 
00274 static void __init nfnl_msg_queue_init(void)
00275 {
00276         nl_cache_mngt_register(&nfnl_queue_msg_ops);
00277 }
00278 
00279 static void __exit nfnl_queue_msg_exit(void)
00280 {
00281         nl_cache_mngt_unregister(&nfnl_queue_msg_ops);
00282 }
00283 
00284 /** @} */