nathelper.c

用来作为linux中SIP SERVER,完成VOIP网络电话中服务器的功能

		fd = socket(AF_LOCAL, SOCK_STREAM, 0);
		if (fd < 0) {
			LOG(L_ERR, "ERROR: send_rtpp_command: can't create socket\n");
			return NULL;
		}
		if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
			close(fd);
			LOG(L_ERR, "ERROR: send_rtpp_command: can't connect to RTP proxy\n");
			return NULL;
		}

		do {
			len = writev(fd, v + 1, vcnt - 1);
		} while (len == -1 && errno == EINTR);
		if (len <= 0) {
			close(fd);
			LOG(L_ERR, "ERROR: send_rtpp_command: can't send command to a RTP proxy\n");
			return NULL;
		}
		do {
			len = read(fd, buf, sizeof(buf) - 1);
		} while (len == -1 && errno == EINTR);
		close(fd);
		if (len <= 0) {
			LOG(L_ERR, "ERROR: send_rtpp_command: can't read reply from a RTP proxy\n");
			return NULL;
		}
	} else {
		fds[0].fd = controlfd;
		fds[0].events = POLLIN;
		fds[0].revents = 0;
		/* Drain input buffer */
		while ((poll(fds, 1, 0) == 1) &&
		    ((fds[0].revents & POLLIN) != 0)) {
			recv(controlfd, buf, sizeof(buf) - 1, 0);
			fds[0].revents = 0;
		}
		v[0].iov_base = gencookie();
		v[0].iov_len = strlen(v[0].iov_base);
		for (i = 0; i < rtpproxy_retr; i++) {
			do {
				len = writev(controlfd, v, vcnt);
			} while (len == -1 && (errno == EINTR || errno == ENOBUFS));
			if (len <= 0) {
				LOG(L_ERR, "ERROR: send_rtpp_command: "
				    "can't send command to a RTP proxy\n");
				return NULL;
			}
			while ((poll(fds, 1, rtpproxy_tout * 1000) == 1) &&
			    (fds[0].revents & POLLIN) != 0) {
				do {
					len = recv(controlfd, buf, sizeof(buf) - 1, 0);
				} while (len == -1 && errno == EINTR);
				if (len <= 0) {
					LOG(L_ERR, "ERROR: send_rtpp_command: "
					    "can't read reply from a RTP proxy\n");
					return NULL;
				}
				if (len >= (v[0].iov_len - 1) &&
				    memcmp(buf, v[0].iov_base, (v[0].iov_len - 1)) == 0) {
					len -= (v[0].iov_len - 1);
					cp += (v[0].iov_len - 1);
					if (len != 0) {
						len--;
						cp++;
					}
					goto out;
				}
				fds[0].revents = 0;
			}
		}
		if (i == rtpproxy_retr) {
			LOG(L_ERR, "ERROR: send_rtpp_command: "
			    "timeout waiting reply from a RTP proxy\n");
			return NULL;
		}
	}

out:
	cp[len] = '\0';
	return cp;
}

static int
unforce_rtp_proxy_f(struct sip_msg* msg, char* str1, char* str2)
{
	str callid, from_tag, to_tag;
	struct iovec v[1 + 4 + 3] = {{NULL, 0}, {"D", 1}, {" ", 1}, {NULL, 0}, {" ", 1}, {NULL, 0}, {" ", 1}, {NULL, 0}};
						/* 1 */   /* 2 */   /* 3 */    /* 4 */   /* 5 */    /* 6 */   /* 1 */

	rtpproxy_disable = rtpp_test(rtpproxy_disable, 0);
	if (rtpproxy_disable != 0) {
		LOG(L_ERR, "ERROR: unforce_rtp_proxy: support for RTP proxy "
		    "is disabled\n");
		return -1;
	}
	if (get_callid(msg, &callid) == -1 || callid.len == 0) {
		LOG(L_ERR, "ERROR: unforce_rtp_proxy: can't get Call-Id field\n");
		return -1;
	}
	if (get_to_tag(msg, &to_tag) == -1) {
		LOG(L_ERR, "ERROR: unforce_rtp_proxy: can't get To tag\n");
		return -1;
	}
	if (get_from_tag(msg, &from_tag) == -1 || from_tag.len == 0) {
		LOG(L_ERR, "ERROR: unforce_rtp_proxy: can't get From tag\n");
		return -1;
	}
	STR2IOVEC(callid, v[3]);
	STR2IOVEC(from_tag, v[5]);
	STR2IOVEC(to_tag, v[7]);
	send_rtpp_command(v, (to_tag.len > 0) ? 8 : 6);

	return 1;
}

static int
force_rtp_proxy2_f(struct sip_msg* msg, char* str1, char* str2)
{
	str body, body1, oldport, oldip, oldip1, newport, newip;
	str callid, from_tag, to_tag, tmp;
	int create, port, len, asymmetric, flookup, argc, proxied, real;
	int oidx, pf, pf1, force;
	char opts[16];
	char *cp, *cp1;
	char  *cpend, *next;
	char **ap, *argv[10];
	struct lump* anchor;
	struct iovec v[1 + 6 + 5] = {{NULL, 0}, {NULL, 0}, {" ", 1}, {NULL, 0},
		{" ", 1}, {NULL, 7}, {" ", 1}, {NULL, 1}, {" ", 1}, {NULL, 0},
		{" ", 1}, {NULL, 0}};
						/* 1 */    /* 2 */   /* 3 */    /* 4 */
		/* 5 */    /* 6 */   /* 7 */    /* 8 */   /* 9 */    /* 10 */
		/* 11 */

	v[1].iov_base=opts;
	asymmetric = flookup = force = real = 0;
	oidx = 1;
	for (cp = str1; *cp != '\0'; cp++) {
		switch (*cp) {
		case 'a':
		case 'A':
			opts[oidx++] = 'A';
			asymmetric = 1;
			real = 1;
			break;

		case 'i':
		case 'I':
			opts[oidx++] = 'I';
			break;

		case 'e':
		case 'E':
			opts[oidx++] = 'E';
			break;

		case 'l':
		case 'L':
			flookup = 1;
			break;

		case 'f':
		case 'F':
			force = 1;
			break;

		case 'r':
		case 'R':
			real = 1;
			break;

		default:
			LOG(L_ERR, "ERROR: force_rtp_proxy2: unknown option `%c'\n", *cp);
			return -1;
		}
	}

	rtpproxy_disable = rtpp_test(rtpproxy_disable, 0);
	if (rtpproxy_disable != 0) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: support for RTP proxy "
		    "is disabled\n");
		return -1;
	}

	if (msg->first_line.type == SIP_REQUEST &&
	    msg->first_line.u.request.method_value == METHOD_INVITE) {
		create = 1;
	} else if (msg->first_line.type == SIP_REPLY) {
		create = 0;
	} else {
		return -1;
	}
	/* extract_body will also parse all the headers in the message as
	 * a side effect => don't move get_callid/get_to_tag in front of it
	 * -- andrei */
	if (extract_body(msg, &body) == -1) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract body "
		    "from the message\n");
		return -1;
	}
	if (get_callid(msg, &callid) == -1 || callid.len == 0) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't get Call-Id field\n");
		return -1;
	}
	if (get_to_tag(msg, &to_tag) == -1) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't get To tag\n");
		return -1;
	}
	if (get_from_tag(msg, &from_tag) == -1 || from_tag.len == 0) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't get From tag\n");
		return -1;
	}
	if (flookup != 0) {
		if (create == 0 || to_tag.len == 0)
			return -1;
		create = 0;
		tmp = from_tag;
		from_tag = to_tag;
		to_tag = tmp;
	}
	proxied = 0;
	for (cp = body.s; (len = body.s + body.len - cp) >= ANORTPPROXY_LEN;) {
		cp1 = ser_memmem(cp, ANORTPPROXY, len, ANORTPPROXY_LEN);
		if (cp1 == NULL)
			break;
		if (cp1[-1] == '\n' || cp1[-1] == '\r') {
			proxied = 1;
			break;
		}
		cp = cp1 + ANORTPPROXY_LEN;
	}
	if (proxied != 0 && force == 0)
		return -1;
	if (extract_mediaip(&body, &oldip, &pf) == -1) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media IP "
		    "from the message\n");
		return -1;
	}
	if (asymmetric != 0 || real != 0) {
		newip = oldip;
	} else {
		newip.s = ip_addr2a(&msg->rcv.src_ip);
		newip.len = strlen(newip.s);
	}
	body1.s = oldip.s + oldip.len;
	body1.len = body.s + body.len - body1.s;
	if (extract_mediaip(&body1, &oldip1, &pf1) == -1) {
		oldip1.len = 0;
	}
	if (oldip1.len > 0 && pf != pf1) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: mismatching address "
		    "families in SDP\n");
		return -1;
	}
	if (extract_mediaport(&body, &oldport) == -1) {
		LOG(L_ERR, "ERROR: force_rtp_proxy2: can't extract media port "
		    "from the message\n");
		return -1;
	}
	if (pf == AF_INET6) {
		opts[oidx] = '6';
		oidx++;
	}
	opts[0] = (create == 0) ? 'L' : 'U';
	v[1].iov_len = oidx;
	STR2IOVEC(callid, v[3]);
	STR2IOVEC(newip, v[5]);
	STR2IOVEC(oldport, v[7]);
	STR2IOVEC(from_tag, v[9]);
	STR2IOVEC(to_tag, v[11]);
	cp = send_rtpp_command(v, (to_tag.len > 0) ? 12 : 10);
	if (cp == NULL)
		return -1;
	argc = 0;
	memset(argv, 0, sizeof(argv));
	cpend=cp+strlen(cp);
	next=eat_token_end(cp, cpend);
	for (ap = argv; cp<cpend; cp=next+1, next=eat_token_end(cp, cpend)){
		*next=0;
		if (*cp != '\0') {
			*ap=cp;
			argc++;
			if ((char*)++ap >= ((char*)argv+sizeof(argv)))
				break;
		}
	}
	if (argc < 1)
		return -1;
	port = atoi(argv[0]);
	if (port <= 0 || port > 65535)
		return -1;

	pf1 = (argc >= 3 && argv[2][0] == '6') ? AF_INET6 : AF_INET;

	if (isnulladdr(&oldip, pf)) {
		if (pf1 == AF_INET6) {
			newip.s = "::";
			newip.len = 2;
		} else {
			newip.s = "0.0.0.0";
			newip.len = 7;
		}
	} else {
		newip.s = (argc < 2) ? str2 : argv[1];
		newip.len = strlen(newip.s);
	}
	newport.s = int2str(port, &newport.len); /* beware static buffer */

	if (alter_mediaip(msg, &body, &oldip, pf, &newip, pf1, 0) == -1)
		return -1;
	if (oldip1.len > 0 &&
	    alter_mediaip(msg, &body1, &oldip1, pf, &newip, pf1, 0) == -1)
		return -1;
	if (alter_mediaport(msg, &body, &oldport, &newport, 0) == -1)
		return -1;

	if (proxied == 0) {
		cp = pkg_malloc(ANORTPPROXY_LEN * sizeof(char));
		if (cp == NULL) {
			LOG(L_ERR, "ERROR: force_rtp_proxy2: out of memory\n");
			return -1;
		}
		anchor = anchor_lump(msg, body.s + body.len - msg->buf, 0, 0);
		if (anchor == NULL) {
			LOG(L_ERR, "ERROR: force_rtp_proxy2: anchor_lump failed\n");
			pkg_free(cp);
			return -1;
		}
		memcpy(cp, ANORTPPROXY, ANORTPPROXY_LEN);
		if (insert_new_lump_after(anchor, cp, ANORTPPROXY_LEN, 0) == NULL) {
			LOG(L_ERR, "ERROR: force_rtp_proxy2: insert_new_lump_after failed\n");
			pkg_free(cp);
			return -1;
		}
	}

	return 1;
}

static int
force_rtp_proxy1_f(struct sip_msg* msg, char* str1, char* str2)
{
	char *cp;
	char newip[IP_ADDR_MAX_STR_SIZE];

	cp = ip_addr2a(&msg->rcv.dst_ip);
	strcpy(newip, cp);
	return force_rtp_proxy2_f(msg, str1, newip);
}

static int
force_rtp_proxy0_f(struct sip_msg* msg, char* str1, char* str2)
{
	char arg[1] = {'\0'};

	return force_rtp_proxy1_f(msg, arg, NULL);
}

static void
timer(unsigned int ticks, void *param)
{
	int rval;
	void *buf, *cp;
	str c;
	struct sip_uri curi;
	union sockaddr_union to;
	struct hostent* he;
	struct socket_info* send_sock;

	buf = NULL;
	if (cblen > 0) {
		buf = pkg_malloc(cblen);
		if (buf == NULL) {
			LOG(L_ERR, "ERROR: nathelper::timer: out of memory\n");
			return;
		}
	}
	rval = ul.get_all_ucontacts(buf, cblen, (ping_nated_only ? FL_NAT : 0));
	if (rval > 0) {
		if (buf != NULL)
			pkg_free(buf);
		cblen = rval * 2;
		buf = pkg_malloc(cblen);
		if (buf == NULL) {
			LOG(L_ERR, "ERROR: nathelper::timer: out of memory\n");
			return;
		}
		rval = ul.get_all_ucontacts(buf, cblen, (ping_nated_only ? FL_NAT : 0));
		if (rval != 0) {
			pkg_free(buf);
			return;
		}
	}

	if (buf == NULL)
		return;

	cp = buf;
	while (1) {
		memcpy(&(c.len), cp, sizeof(c.len));
		if (c.len == 0)
			break;
		c.s = (char*)cp + sizeof(c.len);
		cp =  (char*)cp + sizeof(c.len) + c.len;
		if (parse_uri(c.s, c.len, &curi) < 0) {
			LOG(L_ERR, "ERROR: nathelper::timer: can't parse contact uri\n");
			continue;
		}
		if (curi.proto != PROTO_UDP && curi.proto != PROTO_NONE)
			continue;
		if (curi.port_no == 0)
			curi.port_no = SIP_PORT;
		he = sip_resolvehost(&curi.host, &curi.port_no, PROTO_UDP);
		if (he == NULL){
			LOG(L_ERR, "ERROR: nathelper::timer: can't resolve_hos\n");
			continue;
		}
		hostent2su(&to, he, 0, curi.port_no);
		send_sock=force_socket ? force_socket : 
					get_send_socket(0, &to, PROTO_UDP);
		if (send_sock == NULL) {
			LOG(L_ERR, "ERROR: nathelper::timer: can't get sending socket\n");
			continue;
		}
		udp_send(send_sock, (char *)sbuf, sizeof(sbuf), &to);
	}
	pkg_free(buf);
}


/*
 * Create received SIP uri that will be either
 * passed to registrar in an AVP or apended
 * to Contact header field as a parameter
 */
static int
create_rcv_uri(str* uri, struct sip_msg* m)
{
	static char buf[MAX_URI_SIZE];
	char* p;
	str ip, port;
	int len;
	str proto;

	if (!uri || !m) {
		LOG(L_ERR, "create_rcv_uri: Invalid parameter value\n");
		return -1;
	}

	ip.s = ip_addr2a(&m->rcv.src_ip);
	ip.len = strlen(ip.s);

	port.s = int2str(m->rcv.src_port, &port.len);

	switch(m->rcv.proto) {
	case PROTO_NONE:
	case PROTO_UDP:
		proto.s = 0; /* Do not add transport parameter, UDP is default */
		proto.len = 0;
		break;

	case PROTO_TCP:
		proto.s = "TCP";
		proto.len = 3;
		break;

	case PROTO_TLS:
		proto.s = "TLS";
		proto.len = 3;
		break;

	case PROTO_SCTP:
		proto.s = "SCTP";
		proto.len = 4;
		break;

	default:
		LOG(L_ERR, "BUG: create_rcv_uri: Unknown transport protocol\n");
		return -1;
	}

	len = 4 + ip.len + 1 + port.len;
	if (proto.s) {
		len += TRANSPORT_PARAM_LEN;
		len += proto.len;
	}

	if (len > MAX_URI_SIZE) {
		LOG(L_ERR, "create_rcv_uri: Buffer too small\n");
		return -1;
	}

	p = buf;
	memcpy(p, "sip:", 4);
	p += 4;
	
	memcpy(p, ip.s, ip.len);
	p += ip.len;

	*p++ = ':';
	
	memcpy(p, port.s, port.len);
	p += port.len;

	if (proto.s) {
		memcpy(p, TRANSPORT_PARAM, TRANSPORT_PARAM_LEN);
		p += TRANSPORT_PARAM_LEN;

		memcpy(p, proto.s, proto.len);
		p += proto.len;
	}

	uri->s = buf;
	uri->len = len;

	return 0;
}


/*
 * Add received parameter to Contacts for further
 * forwarding of the REGISTER requuest
 */
static int
add_rcv_param_f(struct sip_msg* msg, char* str1, char* str2)
{
	contact_t* c;
	struct lump* anchor;
	char* param;
	str uri;

	if (create_rcv_uri(&uri, msg) < 0) {
		return -1;
	}

	if (contact_iterator(&c, msg, 0) < 0) {
		return -1;
	}

	while(c) {
		param = (char*)pkg_malloc(RECEIVED_LEN + 2 + uri.len);
		if (!param) {
			LOG(L_ERR, "add_rcv_param: No memory left\n");
			return -1;
		}
		memcpy(param, RECEIVED, RECEIVED_LEN);
		param[RECEIVED_LEN] = '\"';
		memcpy(param + RECEIVED_LEN + 1, uri.s, uri.len);
		param[RECEIVED_LEN + 1 + uri.len] = '\"';

		anchor = anchor_lump(msg, c->name.s + c->len - msg->buf, 0, 0);
		if (anchor == NULL) {
			LOG(L_ERR, "add_rcv_param: anchor_lump failed\n");
			return -1;
		}		

		if (insert_new_lump_after(anchor, param, RECEIVED_LEN + 1 + uri.len + 1, 0) == 0) {
			LOG(L_ERR, "add_rcv_param: insert_new_lump_after failed\n");
			pkg_free(param);
			return -1;
		}

		if (contact_iterator(&c, msg, c) < 0) {
			return -1;
		}
	}

	return 1;
}


/*
 * Create an AVP to be used by registrar with the source IP and port
 * of the REGISTER
 */
static int
fix_nated_register_f(struct sip_msg* msg, char* str1, char* str2)
{
	str uri;
	int_str val;
	int_str rcv_avp;

	if (create_rcv_uri(&uri, msg) < 0) {
		return -1;
	}

	val.s = &uri;

	rcv_avp.n=rcv_avp_no;
	if (add_avp(AVP_VAL_STR, rcv_avp, val) < 0) {
		LOG(L_ERR, "fix_nated_register: Error while creating AVP\n");
		return -1;
	}

	return 1;
}