1 /* 2 * src/nf-queue.c Monitor netfilter queue events 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 (at) trash.net> 10 * Copyright (c) 2010 Karl Hiramoto <karl (at) hiramoto.org> 11 */ 12 13 14 #include <netlink/cli/utils.h> 15 #include <netlink/cli/link.h> 16 #include <netinet/in.h> 17 #include <linux/netfilter.h> 18 #include <linux/netfilter/nfnetlink_queue.h> 19 #include <netlink/netfilter/nfnl.h> 20 #include <netlink/netfilter/queue.h> 21 #include <netlink/netfilter/queue_msg.h> 22 23 static struct nl_sock *nf_sock; 24 25 static struct nfnl_queue *alloc_queue(void) 26 { 27 struct nfnl_queue *queue; 28 29 queue = nfnl_queue_alloc(); 30 if (!queue) 31 nl_cli_fatal(ENOMEM, "Unable to allocate queue object"); 32 33 return queue; 34 } 35 36 37 static void obj_input(struct nl_object *obj, void *arg) 38 { 39 struct nfnl_queue_msg *msg = (struct nfnl_queue_msg *) obj; 40 struct nl_dump_params dp = { 41 .dp_type = NL_DUMP_STATS, 42 .dp_fd = stdout, 43 .dp_dump_msgtype = 1, 44 }; 45 46 nfnl_queue_msg_set_verdict(msg, NF_ACCEPT); 47 nl_object_dump(obj, &dp); 48 nfnl_queue_msg_send_verdict(nf_sock, msg); 49 } 50 51 static int event_input(struct nl_msg *msg, void *arg) 52 { 53 if (nl_msg_parse(msg, &obj_input, NULL) < 0) 54 fprintf(stderr, "<<EVENT>> Unknown message type\n"); 55 56 /* Exit nl_recvmsgs_def() and return to the main select() */ 57 return NL_STOP; 58 } 59 60 int main(int argc, char *argv[]) 61 { 62 struct nl_sock *rt_sock; 63 struct nl_cache *link_cache; 64 struct nfnl_queue *queue; 65 enum nfnl_queue_copy_mode copy_mode; 66 uint32_t copy_range; 67 int err = 1; 68 int family; 69 70 nf_sock = nfnl_queue_socket_alloc(); 71 if (nf_sock == NULL) 72 nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket"); 73 74 nl_socket_disable_seq_check(nf_sock); 75 nl_socket_modify_cb(nf_sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL); 76 77 if ((argc > 1 && !strcasecmp(argv[1], "-h")) || argc < 3) { 78 printf("Usage: nf-queue family group [ copy_mode ] " 79 "[ copy_range ]\n"); 80 printf("family: [ inet | inet6 | ... ] \n"); 81 printf("group: the --queue-num arg that you gave to iptables\n"); 82 printf("copy_mode: [ none | meta | packet ] \n"); 83 return 2; 84 } 85 86 nl_cli_connect(nf_sock, NETLINK_NETFILTER); 87 88 if ((family = nl_str2af(argv[1])) == AF_UNSPEC) 89 nl_cli_fatal(NLE_INVAL, "Unknown family \"%s\"", argv[1]); 90 91 nfnl_queue_pf_unbind(nf_sock, family); 92 if ((err = nfnl_queue_pf_bind(nf_sock, family)) < 0) 93 nl_cli_fatal(err, "Unable to bind logger: %s", 94 nl_geterror(err)); 95 96 queue = alloc_queue(); 97 nfnl_queue_set_group(queue, atoi(argv[2])); 98 99 copy_mode = NFNL_QUEUE_COPY_PACKET; 100 if (argc > 3) { 101 copy_mode = nfnl_queue_str2copy_mode(argv[3]); 102 if (copy_mode < 0) 103 nl_cli_fatal(copy_mode, 104 "Unable to parse copy mode \"%s\": %s", 105 argv[3], nl_geterror(copy_mode)); 106 } 107 nfnl_queue_set_copy_mode(queue, copy_mode); 108 109 copy_range = 0xFFFF; 110 if (argc > 4) 111 copy_range = atoi(argv[4]); 112 nfnl_queue_set_copy_range(queue, copy_range); 113 114 if ((err = nfnl_queue_create(nf_sock, queue)) < 0) 115 nl_cli_fatal(err, "Unable to bind queue: %s", nl_geterror(err)); 116 117 rt_sock = nl_cli_alloc_socket(); 118 nl_cli_connect(rt_sock, NETLINK_ROUTE); 119 link_cache = nl_cli_link_alloc_cache(rt_sock); 120 121 nl_socket_set_buffer_size(nf_sock, 1024*127, 1024*127); 122 123 while (1) { 124 fd_set rfds; 125 int nffd, rtfd, maxfd, retval; 126 127 FD_ZERO(&rfds); 128 129 maxfd = nffd = nl_socket_get_fd(nf_sock); 130 FD_SET(nffd, &rfds); 131 132 rtfd = nl_socket_get_fd(rt_sock); 133 FD_SET(rtfd, &rfds); 134 if (maxfd < rtfd) 135 maxfd = rtfd; 136 137 /* wait for an incoming message on the netlink socket */ 138 retval = select(maxfd+1, &rfds, NULL, NULL, NULL); 139 140 if (retval) { 141 if (FD_ISSET(nffd, &rfds)) 142 nl_recvmsgs_default(nf_sock); 143 if (FD_ISSET(rtfd, &rfds)) 144 nl_recvmsgs_default(rt_sock); 145 } 146 } 147 148 return 0; 149 } 150
