[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 "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;

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