2 * radsniff.c Display the RADIUS traffic on the network.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
20 * Copyright 2006 The FreeRADIUS server project
21 * Copyright 2006 Nicolas Baradakis <nicolas.baradakis@cegetel.net>
24 #include <freeradius-devel/ident.h>
28 #include <freeradius-devel/libradius.h>
32 #include <freeradius-devel/radpaths.h>
33 #include <freeradius-devel/conf.h>
34 #include <freeradius-devel/radsniff.h>
36 static const char *radius_secret = "testing123";
37 static VALUE_PAIR *filter_vps = NULL;
39 static const char *packet_codes[] = {
45 "Accounting-Response",
61 "Resource-Free-Request",
62 "Resource-Free-Response",
63 "Resource-Query-Request",
64 "Resource-Query-Response",
65 "Alternate-Resource-Reclaim-Request",
67 "NAS-Reboot-Response",
90 "IP-Address-Allocate",
95 * Stolen from rad_recv() in ../lib/radius.c
97 static RADIUS_PACKET *init_packet(const uint8_t *data, size_t data_len)
99 RADIUS_PACKET *packet;
102 * Allocate the new request data structure
104 if ((packet = malloc(sizeof(*packet))) == NULL) {
105 librad_log("out of memory");
108 memset(packet, 0, sizeof(*packet));
111 packet->data_len = data_len;
113 if (!rad_packet_ok(packet)) {
119 * Explicitely set the VP list to empty.
126 static int filter_packet(RADIUS_PACKET *packet)
128 VALUE_PAIR *check_item;
130 unsigned int pass, fail;
134 for (vp = packet->vps; vp != NULL; vp = vp->next) {
135 for (check_item = filter_vps;
137 check_item = check_item->next)
138 if ((check_item->attribute == vp->attribute)
139 && (check_item->operator != T_OP_SET)) {
140 compare = paircmp(check_item, vp);
147 if (fail == 0 && pass != 0) {
154 static void got_packet(uint8_t *args, const struct pcap_pkthdr *header, const uint8_t *packet)
156 /* Just a counter of how many packets we've had */
157 static int count = 1;
158 /* Define pointers for packet's attributes */
159 const struct ethernet_header *ethernet; /* The ethernet header */
160 const struct ip_header *ip; /* The IP header */
161 const struct udp_header *udp; /* The UDP header */
162 const uint8_t *payload; /* Packet payload */
163 /* And define the size of the structures we're using */
164 int size_ethernet = sizeof(struct ethernet_header);
165 int size_ip = sizeof(struct ip_header);
166 int size_udp = sizeof(struct udp_header);
168 RADIUS_PACKET *request;
170 args = args; /* -Wunused */
172 /* Define our packet's attributes */
173 ethernet = (const struct ethernet_header*)(packet);
174 ip = (const struct ip_header*)(packet + size_ethernet);
175 udp = (const struct udp_header*)(packet + size_ethernet + size_ip);
176 payload = (const uint8_t *)(packet + size_ethernet + size_ip + size_udp);
178 /* Read the RADIUS packet structure */
179 request = init_packet(payload, header->len - size_ethernet - size_ip - size_udp);
180 if (request == NULL) {
181 librad_perror("check");
184 request->src_ipaddr.ipaddr.ip4addr.s_addr = ip->ip_src.s_addr;
185 request->src_port = ntohs(udp->udp_sport);
186 request->dst_ipaddr.ipaddr.ip4addr.s_addr = ip->ip_dst.s_addr;
187 request->dst_port = ntohs(udp->udp_dport);
190 * Decode the data without bothering to check the signatures.
192 if (rad_decode(request, NULL, radius_secret) != 0) {
193 librad_perror("decode");
196 if (filter_vps && filter_packet(request)) {
197 /* printf("Packet number %d doesn't match\n", count++); */
201 /* Print the RADIUS packet */
202 printf("Packet number %d has just been sniffed\n", count++);
203 printf("\tFrom: %s:%d\n", inet_ntoa(ip->ip_src), ntohs(udp->udp_sport));
204 printf("\tTo: %s:%d\n", inet_ntoa(ip->ip_dst), ntohs(udp->udp_dport));
205 printf("\tType: %s\n", packet_codes[request->code]);
206 if (request->vps != NULL) {
207 vp_printlist(stdout, request->vps);
208 pairfree(&request->vps);
213 static void NEVER_RETURNS usage(int status)
215 FILE *output = status ? stderr : stdout;
216 fprintf(output, "usage: radsniff [options]\n");
217 fprintf(output, "options:\n");
218 fprintf(output, "\t-c count\tNumber of packets to capture.\n");
219 fprintf(output, "\t-d directory\tDirectory where the dictionaries are found\n");
220 fprintf(output, "\t-f filter\tPCAP filter. (default is udp port 1812 or 1813 or 1814)\n");
221 fprintf(output, "\t-h\t\tPrint this help message.\n");
222 fprintf(output, "\t-i interface\tInterface to capture.\n");
223 fprintf(output, "\t-p port\tList for packets on port.\n");
224 fprintf(output, "\t-r filter\tRADIUS attribute filter.\n");
225 fprintf(output, "\t-s secret\tRADIUS secret.\n");
229 int main(int argc, char *argv[])
231 char *dev; /* sniffing device */
232 char errbuf[PCAP_ERRBUF_SIZE]; /* error buffer */
233 pcap_t *descr; /* sniff handler */
234 struct bpf_program fp; /* hold compiled program */
235 bpf_u_int32 maskp; /* subnet mask */
236 bpf_u_int32 netp; /* ip */
238 char *pcap_filter = NULL;
239 char *radius_filter = NULL;
240 int packet_count = -1; /* how many packets to sniff */
242 LRAD_TOKEN parsecode;
243 const char *radius_dir = RADIUS_DIR;
247 dev = pcap_lookupdev(errbuf);
250 while ((opt = getopt(argc, argv, "c:d:f:hi:p:r:s:")) != EOF) {
254 packet_count = atoi(optarg);
255 if (packet_count <= 0) {
256 fprintf(stderr, "radsniff: Invalid number of packets \"%s\"\n", optarg);
264 pcap_filter = optarg;
276 radius_filter = optarg;
277 parsecode = userparse(radius_filter, &filter_vps);
278 if (parsecode == T_OP_INVALID || filter_vps == NULL) {
279 fprintf(stderr, "radsniff: Invalid RADIUS filter \"%s\"\n", optarg);
284 radius_secret = optarg;
292 pcap_filter = buffer;
293 snprintf(buffer, sizeof(buffer), "udp port %d or %d or %d",
294 port, port + 1, port + 2);
297 if (dict_init(radius_dir, RADIUS_DICTIONARY) < 0) {
298 librad_perror("radsniff");
302 pcap_lookupnet(dev, &netp, &maskp, errbuf);
304 /* Print device to the user */
305 printf("Device: [%s]\n", dev);
306 if (packet_count > 0) {
307 printf("Num of packets: [%d]\n", packet_count);
309 printf("PCAP filter: [%s]\n", pcap_filter);
310 if (filter_vps != NULL) {
311 printf("RADIUS filter:\n");
312 vp_printlist(stdout, filter_vps);
314 printf("RADIUS secret: [%s]\n", radius_secret);
316 /* Open the device so we can spy */
317 descr = pcap_open_live(dev, SNAPLEN, 1, 0, errbuf);
320 printf("radsniff: pcap_open_live failed (%s)\n", errbuf);
324 /* Apply the rules */
325 if( pcap_compile(descr, &fp, pcap_filter, 0, netp) == -1)
327 printf("radsniff: pcap_compile failed\n");
330 if (pcap_setfilter(descr, &fp) == -1)
332 printf("radsniff: pcap_setfilter failed\n");
336 /* Now we can set our callback function */
337 pcap_loop(descr, packet_count, got_packet, NULL);
340 printf("Done sniffing\n");