/* $Id: minissdp.c,v 1.1.1.3 2013/07/22 00:32:35 misho Exp $ */ /* MiniUPnP project * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/ * (c) 2006-2013 Thomas Bernard * This software is subject to the conditions detailed * in the LICENCE file provided within the distribution */ #include #include #include #include #include #include #include #include #include #include #include "config.h" #include "upnpdescstrings.h" #include "miniupnpdpath.h" #include "upnphttp.h" #include "upnpglobalvars.h" #include "minissdp.h" #include "upnputils.h" #include "getroute.h" #include "codelength.h" /* SSDP ip/port */ #define SSDP_PORT (1900) #define SSDP_MCAST_ADDR ("239.255.255.250") #define LL_SSDP_MCAST_ADDR "FF02::C" #define SL_SSDP_MCAST_ADDR "FF05::C" /* AddMulticastMembership() * param s socket * param ifaddr ip v4 address */ static int AddMulticastMembership(int s, in_addr_t ifaddr) { struct ip_mreq imr; /* Ip multicast membership */ /* setting up imr structure */ imr.imr_multiaddr.s_addr = inet_addr(SSDP_MCAST_ADDR); /*imr.imr_interface.s_addr = htonl(INADDR_ANY);*/ imr.imr_interface.s_addr = ifaddr; /*inet_addr(ifaddr);*/ if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void *)&imr, sizeof(struct ip_mreq)) < 0) { syslog(LOG_ERR, "setsockopt(udp, IP_ADD_MEMBERSHIP): %m"); return -1; } return 0; } /* AddMulticastMembershipIPv6() * param s socket (IPv6) * To be improved to target specific network interfaces */ #ifdef ENABLE_IPV6 static int AddMulticastMembershipIPv6(int s) { struct ipv6_mreq mr; /*unsigned int ifindex;*/ memset(&mr, 0, sizeof(mr)); inet_pton(AF_INET6, LL_SSDP_MCAST_ADDR, &mr.ipv6mr_multiaddr); /*mr.ipv6mr_interface = ifindex;*/ mr.ipv6mr_interface = 0; /* 0 : all interfaces */ #ifndef IPV6_ADD_MEMBERSHIP #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP #endif if(setsockopt(s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mr, sizeof(struct ipv6_mreq)) < 0) { syslog(LOG_ERR, "setsockopt(udp, IPV6_ADD_MEMBERSHIP): %m"); return -1; } inet_pton(AF_INET6, SL_SSDP_MCAST_ADDR, &mr.ipv6mr_multiaddr); if(setsockopt(s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mr, sizeof(struct ipv6_mreq)) < 0) { syslog(LOG_ERR, "setsockopt(udp, IPV6_ADD_MEMBERSHIP): %m"); return -1; } return 0; } #endif /* Open and configure the socket listening for * SSDP udp packets sent on 239.255.255.250 port 1900 * SSDP v6 udp packets sent on FF02::C, or FF05::C, port 1900 */ int OpenAndConfSSDPReceiveSocket(int ipv6) { int s; struct sockaddr_storage sockname; socklen_t sockname_len; struct lan_addr_s * lan_addr; int j = 1; if( (s = socket(ipv6 ? PF_INET6 : PF_INET, SOCK_DGRAM, 0)) < 0) { syslog(LOG_ERR, "%s: socket(udp): %m", "OpenAndConfSSDPReceiveSocket"); return -1; } memset(&sockname, 0, sizeof(struct sockaddr_storage)); if(ipv6) { struct sockaddr_in6 * saddr = (struct sockaddr_in6 *)&sockname; saddr->sin6_family = AF_INET6; saddr->sin6_port = htons(SSDP_PORT); saddr->sin6_addr = in6addr_any; sockname_len = sizeof(struct sockaddr_in6); } else { struct sockaddr_in * saddr = (struct sockaddr_in *)&sockname; saddr->sin_family = AF_INET; saddr->sin_port = htons(SSDP_PORT); /* NOTE : it seems it doesnt work when binding on the specific address */ /*saddr->sin_addr.s_addr = inet_addr(UPNP_MCAST_ADDR);*/ saddr->sin_addr.s_addr = htonl(INADDR_ANY); /*saddr->sin_addr.s_addr = inet_addr(ifaddr);*/ sockname_len = sizeof(struct sockaddr_in); } if(setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &j, sizeof(j)) < 0) { syslog(LOG_WARNING, "setsockopt(udp, SO_REUSEADDR): %m"); } if(!set_non_blocking(s)) { syslog(LOG_WARNING, "%s: set_non_blocking(): %m", "OpenAndConfSSDPReceiveSocket"); } if(bind(s, (struct sockaddr *)&sockname, sockname_len) < 0) { syslog(LOG_ERR, "%s: bind(udp%s): %m", "OpenAndConfSSDPReceiveSocket", ipv6 ? "6" : ""); close(s); return -1; } #ifdef ENABLE_IPV6 if(ipv6) { AddMulticastMembershipIPv6(s); } else #endif { for(lan_addr = lan_addrs.lh_first; lan_addr != NULL; lan_addr = lan_addr->list.le_next) { if(AddMulticastMembership(s, lan_addr->addr.s_addr) < 0) { syslog(LOG_WARNING, "Failed to add multicast membership for interface %s", lan_addr->str ? lan_addr->str : "NULL"); } } } return s; } /* open the UDP socket used to send SSDP notifications to * the multicast group reserved for them */ static int OpenAndConfSSDPNotifySocket(in_addr_t addr) { int s; unsigned char loopchar = 0; int bcast = 1; unsigned char ttl = 2; /* UDA v1.1 says : The TTL for the IP packet SHOULD default to 2 and SHOULD be configurable. */ /* TODO: Make TTL be configurable */ struct in_addr mc_if; struct sockaddr_in sockname; if( (s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { syslog(LOG_ERR, "socket(udp_notify): %m"); return -1; } mc_if.s_addr = addr; /*inet_addr(addr);*/ if(setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, (char *)&loopchar, sizeof(loopchar)) < 0) { syslog(LOG_ERR, "setsockopt(udp_notify, IP_MULTICAST_LOOP): %m"); close(s); return -1; } if(setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, (char *)&mc_if, sizeof(mc_if)) < 0) { syslog(LOG_ERR, "setsockopt(udp_notify, IP_MULTICAST_IF): %m"); close(s); return -1; } if(setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) { syslog(LOG_WARNING, "setsockopt(udp_notify, IP_MULTICAST_TTL,): %m"); } if(setsockopt(s, SOL_SOCKET, SO_BROADCAST, &bcast, sizeof(bcast)) < 0) { syslog(LOG_ERR, "setsockopt(udp_notify, SO_BROADCAST): %m"); close(s); return -1; } memset(&sockname, 0, sizeof(struct sockaddr_in)); sockname.sin_family = AF_INET; sockname.sin_addr.s_addr = addr; /*inet_addr(addr);*/ if (bind(s, (struct sockaddr *)&sockname, sizeof(struct sockaddr_in)) < 0) { syslog(LOG_ERR, "bind(udp_notify): %m"); close(s); return -1; } return s; } #ifdef ENABLE_IPV6 /* open the UDP socket used to send SSDP notifications to * the multicast group reserved for them. IPv6 */ static int OpenAndConfSSDPNotifySocketIPv6(unsigned int if_index) { int s; unsigned int loop = 0; s = socket(PF_INET6, SOCK_DGRAM, 0); if(s < 0) { syslog(LOG_ERR, "socket(udp_notify IPv6): %m"); return -1; } if(setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, &if_index, sizeof(if_index)) < 0) { syslog(LOG_ERR, "setsockopt(udp_notify IPv6, IPV6_MULTICAST_IF, %u): %m", if_index); close(s); return -1; } if(setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &loop, sizeof(loop)) < 0) { syslog(LOG_ERR, "setsockopt(udp_notify, IPV6_MULTICAST_LOOP): %m"); close(s); return -1; } return s; } #endif int OpenAndConfSSDPNotifySockets(int * sockets) /*OpenAndConfSSDPNotifySockets(int * sockets, struct lan_addr_s * lan_addr, int n_lan_addr)*/ { int i; struct lan_addr_s * lan_addr; for(i=0, lan_addr = lan_addrs.lh_first; lan_addr != NULL; lan_addr = lan_addr->list.le_next) { sockets[i] = OpenAndConfSSDPNotifySocket(lan_addr->addr.s_addr); if(sockets[i] < 0) goto error; i++; #ifdef ENABLE_IPV6 sockets[i] = OpenAndConfSSDPNotifySocketIPv6(lan_addr->index); if(sockets[i] < 0) goto error; i++; #endif } return 0; error: while(--i >= 0) { close(sockets[i]); sockets[i] = -1; } return -1; } /* * response from a LiveBox (Wanadoo) HTTP/1.1 200 OK CACHE-CONTROL: max-age=1800 DATE: Thu, 01 Jan 1970 04:03:23 GMT EXT: LOCATION: http://192.168.0.1:49152/gatedesc.xml SERVER: Linux/2.4.17, UPnP/1.0, Intel SDK for UPnP devices /1.2 ST: upnp:rootdevice USN: uuid:75802409-bccb-40e7-8e6c-fa095ecce13e::upnp:rootdevice * response from a Linksys 802.11b : HTTP/1.1 200 OK Cache-Control:max-age=120 Location:http://192.168.5.1:5678/rootDesc.xml Server:NT/5.0 UPnP/1.0 ST:upnp:rootdevice USN:uuid:upnp-InternetGatewayDevice-1_0-0090a2777777::upnp:rootdevice EXT: */ /* not really an SSDP "announce" as it is the response * to a SSDP "M-SEARCH" */ static void SendSSDPAnnounce2(int s, const struct sockaddr * addr, const char * st, int st_len, const char * suffix, const char * host, unsigned short port) { int l, n; char buf[512]; char addr_str[64]; socklen_t addrlen; /* * follow guideline from document "UPnP Device Architecture 1.0" * uppercase is recommended. * DATE: is recommended * SERVER: OS/ver UPnP/1.0 miniupnpd/1.0 * - check what to put in the 'Cache-Control' header * * have a look at the document "UPnP Device Architecture v1.1 */ l = snprintf(buf, sizeof(buf), "HTTP/1.1 200 OK\r\n" "CACHE-CONTROL: max-age=120\r\n" /*"DATE: ...\r\n"*/ "ST: %.*s%s\r\n" "USN: %s::%.*s%s\r\n" "EXT:\r\n" "SERVER: " MINIUPNPD_SERVER_STRING "\r\n" "LOCATION: http://%s:%u" ROOTDESC_PATH "\r\n" "OPT: \"http://schemas.upnp.org/upnp/1/0/\"; ns=01\r\n" /* UDA v1.1 */ "01-NLS: %u\r\n" /* same as BOOTID. UDA v1.1 */ "BOOTID.UPNP.ORG: %u\r\n" /* UDA v1.1 */ "CONFIGID.UPNP.ORG: %u\r\n" /* UDA v1.1 */ "\r\n", st_len, st, suffix, uuidvalue, st_len, st, suffix, host, (unsigned int)port, upnp_bootid, upnp_bootid, upnp_configid); addrlen = (addr->sa_family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in); n = sendto(s, buf, l, 0, addr, addrlen); sockaddr_to_string(addr, addr_str, sizeof(addr_str)); syslog(LOG_INFO, "SSDP Announce %d bytes to %s ST: %.*s",n, addr_str, l, buf); if(n < 0) { /* XXX handle EINTR, EAGAIN, EWOULDBLOCK */ syslog(LOG_ERR, "sendto(udp): %m"); } } #ifndef IGD_V2 #define IGD_VER 1 #define WANIPC_VER 1 #else #define IGD_VER 2 #define WANIPC_VER 2 #endif static struct { const char * s; const int version; } const known_service_types[] = { {"upnp:rootdevice", 0}, {"urn:schemas-upnp-org:device:InternetGatewayDevice:", IGD_VER}, {"urn:schemas-upnp-org:device:WANConnectionDevice:", 1}, {"urn:schemas-upnp-org:device:WANDevice:", 1}, {"urn:schemas-upnp-org:service:WANCommonInterfaceConfig:", 1}, {"urn:schemas-upnp-org:service:WANIPConnection:", WANIPC_VER}, {"urn:schemas-upnp-org:service:WANPPPConnection:", 1}, #ifdef ENABLE_L3F_SERVICE {"urn:schemas-upnp-org:service:Layer3Forwarding:", 1}, #endif #ifdef ENABLE_6FC_SERVICE {"url:schemas-upnp-org:service:WANIPv6FirewallControl:", 1}, #endif {0, 0} }; static void SendSSDPNotifies(int s, const char * host, unsigned short port, unsigned int lifetime, int ipv6) { #ifdef ENABLE_IPV6 struct sockaddr_storage sockname; #else struct sockaddr_in sockname; #endif int l, n, i=0; char bufr[512]; char ver_str[4]; memset(&sockname, 0, sizeof(sockname)); #ifdef ENABLE_IPV6 if(ipv6) { struct sockaddr_in6 * p = (struct sockaddr_in6 *)&sockname; p->sin6_family = AF_INET6; p->sin6_port = htons(SSDP_PORT); inet_pton(AF_INET6, LL_SSDP_MCAST_ADDR, &(p->sin6_addr)); } else #endif { struct sockaddr_in *p = (struct sockaddr_in *)&sockname; p->sin_family = AF_INET; p->sin_port = htons(SSDP_PORT); p->sin_addr.s_addr = inet_addr(SSDP_MCAST_ADDR); } while(known_service_types[i].s) { if(i==0) ver_str[0] = '\0'; else snprintf(ver_str, sizeof(ver_str), "%d", known_service_types[i].version); l = snprintf(bufr, sizeof(bufr), "NOTIFY * HTTP/1.1\r\n" "HOST: %s:%d\r\n" "CACHE-CONTROL: max-age=%u\r\n" "lOCATION: http://%s:%d" ROOTDESC_PATH"\r\n" "SERVER: " MINIUPNPD_SERVER_STRING "\r\n" "NT: %s%s\r\n" "USN: %s::%s%s\r\n" "NTS: ssdp:alive\r\n" "OPT: \"http://schemas.upnp.org/upnp/1/0/\"; ns=01\r\n" /* UDA v1.1 */ "01-NLS: %u\r\n" /* same as BOOTID field. UDA v1.1 */ "BOOTID.UPNP.ORG: %u\r\n" /* UDA v1.1 */ "CONFIGID.UPNP.ORG: %u\r\n" /* UDA v1.1 */ "\r\n", ipv6 ? "[" LL_SSDP_MCAST_ADDR "]" : SSDP_MCAST_ADDR, SSDP_PORT, lifetime, host, port, known_service_types[i].s, ver_str, uuidvalue, known_service_types[i].s, ver_str, upnp_bootid, upnp_bootid, upnp_configid ); if(l<0) { syslog(LOG_ERR, "SendSSDPNotifies() snprintf error"); continue; } if((unsigned int)l >= sizeof(bufr)) { syslog(LOG_WARNING, "SendSSDPNotifies(): truncated output"); l = sizeof(bufr); } n = sendto(s, bufr, l, 0, (struct sockaddr *)&sockname, #ifdef ENABLE_IPV6 ipv6 ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in) #else sizeof(struct sockaddr_in) #endif ); if(n < 0) { /* XXX handle EINTR, EAGAIN, EWOULDBLOCK */ syslog(LOG_ERR, "sendto(udp_notify=%d, %s): %m", s, host ? host : "NULL"); } i++; } } void SendSSDPNotifies2(int * sockets, unsigned short port, unsigned int lifetime) { int i; struct lan_addr_s * lan_addr; for(i=0, lan_addr = lan_addrs.lh_first; lan_addr != NULL; lan_addr = lan_addr->list.le_next) { SendSSDPNotifies(sockets[i], lan_addr->str, port, lifetime, 0); i++; #ifdef ENABLE_IPV6 SendSSDPNotifies(sockets[i], ipv6_addr_for_http_with_brackets, port, lifetime, 1); i++; #endif } } /* ProcessSSDPRequest() * process SSDP M-SEARCH requests and responds to them */ void ProcessSSDPRequest(int s, unsigned short port) { int n; char bufr[1500]; socklen_t len_r; #ifdef ENABLE_IPV6 struct sockaddr_storage sendername; len_r = sizeof(struct sockaddr_storage); #else struct sockaddr_in sendername; len_r = sizeof(struct sockaddr_in); #endif n = recvfrom(s, bufr, sizeof(bufr), 0, (struct sockaddr *)&sendername, &len_r); if(n < 0) { /* EAGAIN, EWOULDBLOCK, EINTR : silently ignore (try again next time) * other errors : log to LOG_ERR */ if(errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR) { syslog(LOG_ERR, "recvfrom(udp): %m"); } return; } ProcessSSDPData(s, bufr, n, (struct sockaddr *)&sendername, port); } void ProcessSSDPData(int s, const char *bufr, int n, const struct sockaddr * sender, unsigned short port) { int i, l; struct lan_addr_s * lan_addr = NULL; const char * st = NULL; int st_len = 0; int st_ver = 0; char sender_str[64]; char ver_str[4]; const char * announced_host = NULL; #ifdef ENABLE_IPV6 #ifdef UPNP_STRICT char announced_host_buf[64]; #endif #endif /* get the string representation of the sender address */ sockaddr_to_string(sender, sender_str, sizeof(sender_str)); lan_addr = get_lan_for_peer(sender); if(lan_addr == NULL) { syslog(LOG_WARNING, "SSDP packet sender %s not from a LAN, ignoring", sender_str); return; } if(memcmp(bufr, "NOTIFY", 6) == 0) { /* ignore NOTIFY packets. We could log the sender and device type */ return; } else if(memcmp(bufr, "M-SEARCH", 8) == 0) { i = 0; while(i < n) { while((i < n - 1) && (bufr[i] != '\r' || bufr[i+1] != '\n')) i++; i += 2; if((i < n - 3) && (strncasecmp(bufr+i, "st:", 3) == 0)) { st = bufr+i+3; st_len = 0; while((*st == ' ' || *st == '\t') && (st < bufr + n)) st++; while(st[st_len]!='\r' && st[st_len]!='\n' && (st + st_len < bufr + n)) st_len++; l = st_len; while(l > 0 && st[l-1] != ':') l--; st_ver = atoi(st+l); syslog(LOG_DEBUG, "ST: %.*s (ver=%d)", st_len, st, st_ver); /*j = 0;*/ /*while(bufr[i+j]!='\r') j++;*/ /*syslog(LOG_INFO, "%.*s", j, bufr+i);*/ } } /*syslog(LOG_INFO, "SSDP M-SEARCH packet received from %s", sender_str );*/ if(st && (st_len > 0)) { /* TODO : doesnt answer at once but wait for a random time */ syslog(LOG_INFO, "SSDP M-SEARCH from %s ST: %.*s", sender_str, st_len, st); /* find in which sub network the client is */ if(sender->sa_family == AF_INET) { if (lan_addr == NULL) { syslog(LOG_ERR, "Can't find in which sub network the client is"); return; } announced_host = lan_addr->str; } #ifdef ENABLE_IPV6 else { /* IPv6 address with brackets */ #ifdef UPNP_STRICT int index; struct in6_addr addr6; size_t addr6_len = sizeof(addr6); /* retrieve the IPv6 address which * will be used locally to reach sender */ memset(&addr6, 0, sizeof(addr6)); if(get_src_for_route_to (sender, &addr6, &addr6_len, &index) < 0) { syslog(LOG_WARNING, "get_src_for_route_to() failed, using %s", ipv6_addr_for_http_with_brackets); announced_host = ipv6_addr_for_http_with_brackets; } else { if(inet_ntop(AF_INET6, &addr6, announced_host_buf+1, sizeof(announced_host_buf) - 2)) { announced_host_buf[0] = '['; i = strlen(announced_host_buf); if(i < (int)sizeof(announced_host_buf) - 1) { announced_host_buf[i] = ']'; announced_host_buf[i+1] = '\0'; } else { syslog(LOG_NOTICE, "cannot suffix %s with ']'", announced_host_buf); } announced_host = announced_host_buf; } else { syslog(LOG_NOTICE, "inet_ntop() failed %m"); announced_host = ipv6_addr_for_http_with_brackets; } } #else announced_host = ipv6_addr_for_http_with_brackets; #endif } #endif /* Responds to request with a device as ST header */ for(i = 0; known_service_types[i].s; i++) { l = (int)strlen(known_service_types[i].s); if(l<=st_len && (0 == memcmp(st, known_service_types[i].s, l)) #ifdef UPNP_STRICT && (st_ver <= known_service_types[i].version) /* only answer for service version lower or equal of supported one */ #endif ) { syslog(LOG_INFO, "Single search found"); SendSSDPAnnounce2(s, sender, st, st_len, "", announced_host, port); break; } } /* Responds to request with ST: ssdp:all */ /* strlen("ssdp:all") == 8 */ if(st_len==8 && (0 == memcmp(st, "ssdp:all", 8))) { syslog(LOG_INFO, "ssdp:all found"); for(i=0; known_service_types[i].s; i++) { if(i==0) ver_str[0] = '\0'; else snprintf(ver_str, sizeof(ver_str), "%d", known_service_types[i].version); l = (int)strlen(known_service_types[i].s); SendSSDPAnnounce2(s, sender, known_service_types[i].s, l, ver_str, announced_host, port); } /* also answer for uuid */ SendSSDPAnnounce2(s, sender, uuidvalue, strlen(uuidvalue), "", announced_host, port); } /* responds to request by UUID value */ l = (int)strlen(uuidvalue); if(l==st_len && (0 == memcmp(st, uuidvalue, l))) { syslog(LOG_INFO, "ssdp:uuid found"); SendSSDPAnnounce2(s, sender, st, st_len, "", announced_host, port); } } else { syslog(LOG_INFO, "Invalid SSDP M-SEARCH from %s", sender_str); } } else { syslog(LOG_NOTICE, "Unknown udp packet received from %s", sender_str); } } /* This will broadcast ssdp:byebye notifications to inform * the network that UPnP is going down. */ int SendSSDPGoodbye(int * sockets, int n_sockets) { struct sockaddr_in sockname; #ifdef ENABLE_IPV6 struct sockaddr_in6 sockname6; #endif int n, l; int i, j; char bufr[512]; char ver_str[4]; int ret = 0; int ipv6 = 0; memset(&sockname, 0, sizeof(struct sockaddr_in)); sockname.sin_family = AF_INET; sockname.sin_port = htons(SSDP_PORT); sockname.sin_addr.s_addr = inet_addr(SSDP_MCAST_ADDR); #ifdef ENABLE_IPV6 memset(&sockname6, 0, sizeof(struct sockaddr_in6)); sockname6.sin6_family = AF_INET6; sockname6.sin6_port = htons(SSDP_PORT); inet_pton(AF_INET6, LL_SSDP_MCAST_ADDR, &(sockname6.sin6_addr)); #endif for(j=0; j 0) l++; CODELENGTH(l, p); memcpy(p, known_service_types[i].s, l); if(i > 0) p[l-1] = '1'; p += l; if(i==0) ver_str[0] = '\0'; else snprintf(ver_str, sizeof(ver_str), "%d", known_service_types[i].version); l = snprintf(strbuf, sizeof(strbuf), "%s::%s%s", uuidvalue, known_service_types[i].s, ver_str); CODELENGTH(l, p); memcpy(p, strbuf, l); p += l; l = (int)strlen(MINIUPNPD_SERVER_STRING); CODELENGTH(l, p); memcpy(p, MINIUPNPD_SERVER_STRING, l); p += l; l = snprintf(strbuf, sizeof(strbuf), "http://%s:%u" ROOTDESC_PATH, host, (unsigned int)port); CODELENGTH(l, p); memcpy(p, strbuf, l); p += l; /* now write the encoded data */ n = p - buffer; /* bytes to send */ p = buffer; /* start */ while(n > 0) { l = write(s, p, n); if (l < 0) { syslog(LOG_ERR, "write(): %m"); close(s); return -1; } else if (l == 0) { syslog(LOG_ERR, "write() returned 0"); close(s); return -1; } p += l; n -= l; } } close(s); return 0; }