[record-dvb] / sap.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>         
#include <arpa/inet.h>
#include <sys/time.h>
#include <time.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <sys/select.h>

#include "mcast.h"
#include "sap.h"

#define SAP_ADDR	"224.2.127.254"
#define SAP_PORT	9875
#define SAP_MAX_SIZE	1024

#define SAP_TIMEOUT	3

#define BUFFSIZE	SAP_MAX_SIZE

char *get_url_from_sap(char *service)
{
	struct timeval start, curr;
	struct ip_mreq mreq;
	unsigned char buffer[BUFFSIZE];
	char *url = NULL;
	int fd;

	snprintf(buffer,BUFFSIZE,"udp://%s:%u", SAP_ADDR, SAP_PORT);

	fd = open_mcast(buffer);

	gettimeofday(&start, NULL);

	do {
		int recvd;
		int sap_version, sap_addrtype, sap_messagetype, sap_encrypted, sap_compressed;
		in_addr_t sender_address;
		unsigned char auth_len;
		unsigned short msgid;
		unsigned char *payload, *pos, *host = NULL, *proto = NULL, *port = NULL, *sname = NULL;
		fd_set rfds;
		struct timeval tv;
		int retval;

		FD_ZERO(&rfds);
		FD_SET(fd, &rfds);

		tv.tv_sec = 0;
		tv.tv_usec = 100000;

		if ((retval = select(fd+1, &rfds, NULL, NULL, &tv)) == -1) {
			perror("select");
			return NULL;
		}

		if (!retval) {
			gettimeofday(&curr, NULL);
			continue;
		}

		if ((recvd = recv(fd, buffer, BUFFSIZE, 0)) < 1) {
			perror("recv");
			return NULL;
		}

		gettimeofday(&curr, NULL);

		sap_version = (buffer[0] >> 5) & 0x7;
		sap_addrtype = (buffer[0] >> 4) & 0x1;
		sap_messagetype = (buffer[0] >> 2) & 0x1;
		sap_encrypted = (buffer[0] >> 1) & 0x1;
		sap_compressed = buffer[0] & 0x1;
		auth_len = buffer[1];
		msgid = buffer[2] << 8 | buffer[3];
		memcpy(&sender_address, buffer+4, (sap_addrtype?16:4));
		payload = buffer + 4 /* (sap_*, auth_len, msgid) */ + (sap_addrtype?16:4) + auth_len;

#ifdef DEBUG
		printf("\n");
		printf("SAP-Version: %d\n", sap_version);
		printf("Adresstyp: %s\n", (sap_addrtype?"IPv6":"IPv4"));
		printf("Messagetype: %s\n", (sap_messagetype?"Announcement":"Deletion"));
		printf("Encrypted: %d\n", sap_encrypted);
		printf("Compressed: %d\n", sap_compressed);
		printf("Authentication Length: %d\n", auth_len);
		printf("Sender: %u\n", sender_address);
		printf("Message Identifier Hash: %u\n", msgid);
#endif

		if (sap_addrtype)
			continue; /* We don't support IPv6 for now */

#if 0 /* Getstream gets this wrong, see rfc2974 */
		if (sap_messagetype)
			continue; /* We are not interested in deletions */
#endif

		if (sap_encrypted || sap_compressed)
			continue;

		/* RFC 2327
		 * v=0
		 * o=- 6dca 1 IN IP4 192.168.100.17:2000
		 * s=TV Das Erste
		 * t=0 0
		 * c=IN IP4 192.168.100.17/1
		 * m=video 2000 http 33
		 * a=tool:getstream
		 * a=type:broadcast
		 */

		pos = payload;
		while(*pos != 0 && (pos-buffer) < BUFFSIZE) {
			if (*pos == 0x0d) {
				*pos = 0;
			}

			if (*pos == 0x0a) {
				*pos = 0;

				if (!strncasecmp("s=", payload, 2)) {
					sname = payload + 2;
				} else if (!strncasecmp("c=", payload, 2)) {
					int poscnt = 0;

					payload += 2;
					while (*payload != 0) {
						if (poscnt == 2 && *payload == '/') {
							*payload = 0;
							break;
						}

						if (*payload == ' ') {
							*payload = 0;
							poscnt++;

							/* c=<network type> <address type> <connection address> */
							if (poscnt == 2) { 
								host = payload + 1;
							}

							if (poscnt > 2) {
								break;
							}
						}
						payload++;
					}
				} else if (!strncasecmp("m=", payload, 2)) {
					int poscnt = 0;

					payload += 2;
					while (*payload != 0) {
						if (*payload == ' ') {
							*payload = 0;
							poscnt++;

							/* m=<media> <port> <transport> <fmt list> */
							if (poscnt == 1) { 
								port = payload + 1;
							}

							if (poscnt == 2) { 
								proto = payload + 1;
							}

							if (poscnt > 2) {
								break;
							}
						}
						payload++;
					}
				}

				payload = ++pos;
				continue;
			}
			pos++;
		}

		if (sname && proto && port) {
			if (!host) {
				 struct in_addr inaddr;

				 inaddr.s_addr = sender_address;
				 host = inet_ntoa(inaddr);
			}

#ifdef DEBUG
			printf("%s -> %s://%s:%s\n", sname, proto, host, port);
#endif

			if (strlen(service) < strlen(sname)) {
				sname += strlen(sname) - strlen(service);
			}

			if (!strncasecmp(service, sname, strlen(service))) {
				int len = strlen(host)+strlen(proto)+strlen(port)+5;

				if (!(url = malloc(len))) {
					perror("malloc");
					return NULL;
				}

				snprintf(url, len, "%s://%s:%s", proto, host, port);
				url[len-1] = 0;
				break;
			}
		}

	} while(curr.tv_sec < start.tv_sec+SAP_TIMEOUT);

	mreq.imr_multiaddr.s_addr = inet_addr(SAP_ADDR);
	mreq.imr_interface.s_addr = INADDR_ANY;
	setsockopt (fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));

	close(fd);

	return url;
}
Commit	Line	Data
8447845f	1	#include <stdio.h>
	2	#include <stdlib.h>
	3	#include <sys/types.h>
	4	#include <sys/socket.h>
	5	#include <netinet/in.h>
	6	#include <arpa/inet.h>
	7	#include <sys/time.h>
	8	#include <time.h>
	9	#include <string.h>
	10	#include <strings.h>
89ec024f	11	#include <unistd.h>
89ec024f	12	#include <sys/select.h>
8447845f	13
	14	#include "mcast.h"
	15	#include "sap.h"
	16
	17	#define SAP_ADDR "224.2.127.254"
	18	#define SAP_PORT 9875
	19	#define SAP_MAX_SIZE 1024
	20
	21	#define SAP_TIMEOUT 3
	22
	23	#define BUFFSIZE SAP_MAX_SIZE
	24
	25	char get_url_from_sap(char service)
	26	{
	27	struct timeval start, curr;
	28	struct ip_mreq mreq;
	29	unsigned char buffer[BUFFSIZE];
	30	char *url = NULL;
	31	int fd;
	32
	33	snprintf(buffer,BUFFSIZE,"udp://%s:%u", SAP_ADDR, SAP_PORT);
	34
	35	fd = open_mcast(buffer);
	36
	37	gettimeofday(&start, NULL);
	38
	39	do {
	40	int recvd;
	41	int sap_version, sap_addrtype, sap_messagetype, sap_encrypted, sap_compressed;
	42	in_addr_t sender_address;
	43	unsigned char auth_len;
	44	unsigned short msgid;
	45	unsigned char payload, pos, host = NULL, proto = NULL, port = NULL, sname = NULL;
89ec024f	46	fd_set rfds;
	47	struct timeval tv;
	48	int retval;
	49
	50	FD_ZERO(&rfds);
	51	FD_SET(fd, &rfds);
	52
	53	tv.tv_sec = 0;
d5b58906	54	tv.tv_usec = 100000;
89ec024f	55
	56	if ((retval = select(fd+1, &rfds, NULL, NULL, &tv)) == -1) {
	57	perror("select");
	58	return NULL;
	59	}
	60
	61	if (!retval) {
	62	gettimeofday(&curr, NULL);
	63	continue;
	64	}
8447845f	65
	66	if ((recvd = recv(fd, buffer, BUFFSIZE, 0)) < 1) {
	67	perror("recv");
	68	return NULL;
	69	}
	70
	71	gettimeofday(&curr, NULL);
	72
	73	sap_version = (buffer[0] >> 5) & 0x7;
	74	sap_addrtype = (buffer[0] >> 4) & 0x1;
	75	sap_messagetype = (buffer[0] >> 2) & 0x1;
	76	sap_encrypted = (buffer[0] >> 1) & 0x1;
	77	sap_compressed = buffer[0] & 0x1;
	78	auth_len = buffer[1];
	79	msgid = buffer[2] << 8 \| buffer[3];
	80	memcpy(&sender_address, buffer+4, (sap_addrtype?16:4));
	81	payload = buffer + 4 /* (sap_, auth_len, msgid) / + (sap_addrtype?16:4) + auth_len;
	82
	83	#ifdef DEBUG
	84	printf("\n");
	85	printf("SAP-Version: %d\n", sap_version);
	86	printf("Adresstyp: %s\n", (sap_addrtype?"IPv6":"IPv4"));
	87	printf("Messagetype: %s\n", (sap_messagetype?"Announcement":"Deletion"));
	88	printf("Encrypted: %d\n", sap_encrypted);
	89	printf("Compressed: %d\n", sap_compressed);
	90	printf("Authentication Length: %d\n", auth_len);
	91	printf("Sender: %u\n", sender_address);
	92	printf("Message Identifier Hash: %u\n", msgid);
	93	#endif
	94
	95	if (sap_addrtype)
	96	continue; /* We don't support IPv6 for now */
	97
	98	#if 0 /* Getstream gets this wrong, see rfc2974 */
	99	if (sap_messagetype)
	100	continue; /* We are not interested in deletions */
	101	#endif
	102
	103	if (sap_encrypted \|\| sap_compressed)
	104	continue;
b06a3250	105
8447845f	106	/* RFC 2327
	107	* v=0
	108	* o=- 6dca 1 IN IP4 192.168.100.17:2000
	109	* s=TV Das Erste
	110	* t=0 0
	111	* c=IN IP4 192.168.100.17/1
	112	* m=video 2000 http 33
	113	* a=tool:getstream
	114	* a=type:broadcast
	115	*/
	116
	117	pos = payload;
	118	while(*pos != 0 && (pos-buffer) < BUFFSIZE) {
	119	if (*pos == 0x0d) {
	120	*pos = 0;
	121	}
	122
	123	if (*pos == 0x0a) {
	124	*pos = 0;
	125
	126	if (!strncasecmp("s=", payload, 2)) {
	127	sname = payload + 2;
	128	} else if (!strncasecmp("c=", payload, 2)) {
	129	int poscnt = 0;
	130
	131	payload += 2;
	132	while (*payload != 0) {
	133	if (poscnt == 2 && *payload == '/') {
	134	*payload = 0;
	135	break;
	136	}
	137
	138	if (*payload == ' ') {
	139	*payload = 0;
	140	poscnt++;
	141
	142	/* c=<network type> <address type> <connection address> */
	143	if (poscnt == 2) {
	144	host = payload + 1;
	145	}
	146
	147	if (poscnt > 2) {
	148	break;
	149	}
	150	}
	151	payload++;
	152	}
	153	} else if (!strncasecmp("m=", payload, 2)) {
	154	int poscnt = 0;
	155
	156	payload += 2;
	157	while (*payload != 0) {
	158	if (*payload == ' ') {
	159	*payload = 0;
	160	poscnt++;
	161
	162	/* m=<media> <port> <transport> <fmt list> */
	163	if (poscnt == 1) {
	164	port = payload + 1;
	165	}
	166
	167	if (poscnt == 2) {
	168	proto = payload + 1;
	169	}
170
171	if (poscnt > 2) {
172	break;
173	}
174	}
175	payload++;
176	}
177	}
178
179	payload = ++pos;
180	continue;
181	}
182	pos++;
183	}
184
185	if (sname && proto && port) {
186	if (!host) {
187	struct in_addr inaddr;
188
189	inaddr.s_addr = sender_address;
190	host = inet_ntoa(inaddr);
191	}
192
193	#ifdef DEBUG
194	printf("%s -> %s://%s:%s\n", sname, proto, host, port);
195	#endif
196
197	if (strlen(service) < strlen(sname)) {
198	sname += strlen(sname) - strlen(service);
199	}
200
201	if (!strncasecmp(service, sname, strlen(service))) {
202	int len = strlen(host)+strlen(proto)+strlen(port)+5;
203
204	if (!(url = malloc(len))) {
205	perror("malloc");
206	return NULL;
207	}
208
209	snprintf(url, len, "%s://%s:%s", proto, host, port);
210	url[len-1] = 0;
211	break;
212	}
213	}
214
215	} while(curr.tv_sec < start.tv_sec+SAP_TIMEOUT);
216
217	mreq.imr_multiaddr.s_addr = inet_addr(SAP_ADDR);
218	mreq.imr_interface.s_addr = INADDR_ANY;
219	setsockopt (fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
220
90d8d87b	221	close(fd);
90d8d87b	222
8447845f	223	return url;
8447845f	224	}