int create_server_socket(const char *host, const char *port) { struct addrinfo hints; struct addrinfo *result, *rp; int s, server_sock; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = AF_UNSPEC; /* Return IPv4 and IPv6 choices */ hints.ai_socktype = SOCK_DGRAM; /* We want a UDP socket */ s = getaddrinfo(host, port, &hints, &result); if (s != 0) { LOGE("[udp] getaddrinfo: %s", gai_strerror(s)); return -1; } for (rp = result; rp != NULL; rp = rp->ai_next) { server_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (server_sock == -1) { continue; } int opt = 1; setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); #ifdef SO_NOSIGPIPE set_nosigpipe(server_sock); #endif s = bind(server_sock, rp->ai_addr, rp->ai_addrlen); if (s == 0) { /* We managed to bind successfully! */ break; } else { ERROR("[udp] bind"); } close(server_sock); } if (rp == NULL) { LOGE("[udp] cannot bind"); return -1; } freeaddrinfo(result); return server_sock; }
static void server_recv_cb(EV_P_ ev_io *w, int revents) { server_ctx_t *server_ctx = (server_ctx_t *)w; struct sockaddr_storage src_addr; memset(&src_addr, 0, sizeof(struct sockaddr_storage)); buffer_t *buf = ss_malloc(sizeof(buffer_t)); balloc(buf, buf_size); socklen_t src_addr_len = sizeof(struct sockaddr_storage); unsigned int offset = 0; #ifdef MODULE_REDIR char control_buffer[64] = { 0 }; struct msghdr msg; memset(&msg, 0, sizeof(struct msghdr)); struct iovec iov[1]; struct sockaddr_storage dst_addr; memset(&dst_addr, 0, sizeof(struct sockaddr_storage)); msg.msg_name = &src_addr; msg.msg_namelen = src_addr_len; msg.msg_control = control_buffer; msg.msg_controllen = sizeof(control_buffer); iov[0].iov_base = buf->data; iov[0].iov_len = buf_size; msg.msg_iov = iov; msg.msg_iovlen = 1; buf->len = recvmsg(server_ctx->fd, &msg, 0); if (buf->len == -1) { ERROR("[udp] server_recvmsg"); goto CLEAN_UP; } else if (buf->len > packet_size) { if (verbose) { LOGI("[udp] UDP server_recv_recvmsg fragmentation"); } } if (get_dstaddr(&msg, &dst_addr)) { LOGE("[udp] unable to get dest addr"); goto CLEAN_UP; } src_addr_len = msg.msg_namelen; #else ssize_t r; r = recvfrom(server_ctx->fd, buf->data, buf_size, 0, (struct sockaddr *)&src_addr, &src_addr_len); if (r == -1) { // error on recv // simply drop that packet ERROR("[udp] server_recv_recvfrom"); goto CLEAN_UP; } else if (r > packet_size) { if (verbose) { LOGI("[udp] server_recv_recvfrom fragmentation"); } } buf->len = r; #endif if (verbose) { LOGI("[udp] server receive a packet"); } #ifdef MODULE_REMOTE tx += buf->len; int err = server_ctx->crypto->decrypt_all(buf, server_ctx->crypto->cipher, buf_size); if (err) { // drop the packet silently goto CLEAN_UP; } #endif #ifdef MODULE_LOCAL #if !defined(MODULE_TUNNEL) && !defined(MODULE_REDIR) #ifdef __ANDROID__ tx += buf->len; #endif uint8_t frag = *(uint8_t *)(buf->data + 2); offset += 3; #endif #endif /* * * SOCKS5 UDP Request * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * SOCKS5 UDP Response * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * shadowsocks UDP Request (before encrypted) * +------+----------+----------+----------+ * | ATYP | DST.ADDR | DST.PORT | DATA | * +------+----------+----------+----------+ * | 1 | Variable | 2 | Variable | * +------+----------+----------+----------+ * * shadowsocks UDP Response (before encrypted) * +------+----------+----------+----------+ * | ATYP | DST.ADDR | DST.PORT | DATA | * +------+----------+----------+----------+ * | 1 | Variable | 2 | Variable | * +------+----------+----------+----------+ * * shadowsocks UDP Request and Response (after encrypted) * +-------+--------------+ * | IV | PAYLOAD | * +-------+--------------+ * | Fixed | Variable | * +-------+--------------+ * */ #ifdef MODULE_REDIR char addr_header[512] = { 0 }; int addr_header_len = construct_udprelay_header(&dst_addr, addr_header); if (addr_header_len == 0) { LOGE("[udp] failed to parse tproxy addr"); goto CLEAN_UP; } // reconstruct the buffer brealloc(buf, buf->len + addr_header_len, buf_size); memmove(buf->data + addr_header_len, buf->data, buf->len); memcpy(buf->data, addr_header, addr_header_len); buf->len += addr_header_len; #elif MODULE_TUNNEL char addr_header[512] = { 0 }; char *host = server_ctx->tunnel_addr.host; char *port = server_ctx->tunnel_addr.port; uint16_t port_num = (uint16_t)atoi(port); uint16_t port_net_num = htons(port_num); int addr_header_len = 0; struct cork_ip ip; if (cork_ip_init(&ip, host) != -1) { if (ip.version == 4) { // send as IPv4 struct in_addr host_addr; memset(&host_addr, 0, sizeof(struct in_addr)); int host_len = sizeof(struct in_addr); if (dns_pton(AF_INET, host, &host_addr) == -1) { FATAL("IP parser error"); } addr_header[addr_header_len++] = 1; memcpy(addr_header + addr_header_len, &host_addr, host_len); addr_header_len += host_len; } else if (ip.version == 6) { // send as IPv6 struct in6_addr host_addr; memset(&host_addr, 0, sizeof(struct in6_addr)); int host_len = sizeof(struct in6_addr); if (dns_pton(AF_INET6, host, &host_addr) == -1) { FATAL("IP parser error"); } addr_header[addr_header_len++] = 4; memcpy(addr_header + addr_header_len, &host_addr, host_len); addr_header_len += host_len; } else { FATAL("IP parser error"); } } else { // send as domain int host_len = strlen(host); addr_header[addr_header_len++] = 3; addr_header[addr_header_len++] = host_len; memcpy(addr_header + addr_header_len, host, host_len); addr_header_len += host_len; } memcpy(addr_header + addr_header_len, &port_net_num, 2); addr_header_len += 2; // reconstruct the buffer brealloc(buf, buf->len + addr_header_len, buf_size); memmove(buf->data + addr_header_len, buf->data, buf->len); memcpy(buf->data, addr_header, addr_header_len); buf->len += addr_header_len; #else char host[257] = { 0 }; char port[64] = { 0 }; struct sockaddr_storage dst_addr; memset(&dst_addr, 0, sizeof(struct sockaddr_storage)); int addr_header_len = parse_udprelay_header(buf->data + offset, buf->len - offset, host, port, &dst_addr); if (addr_header_len == 0) { // error in parse header goto CLEAN_UP; } char *addr_header = buf->data + offset; #endif #ifdef MODULE_LOCAL char *key = hash_key(server_ctx->remote_addr->sa_family, &src_addr); #else char *key = hash_key(dst_addr.ss_family, &src_addr); #endif struct cache *conn_cache = server_ctx->conn_cache; remote_ctx_t *remote_ctx = NULL; cache_lookup(conn_cache, key, HASH_KEY_LEN, (void *)&remote_ctx); if (remote_ctx != NULL) { if (sockaddr_cmp(&src_addr, &remote_ctx->src_addr, sizeof(src_addr))) { remote_ctx = NULL; } } // reset the timer if (remote_ctx != NULL) { ev_timer_again(EV_A_ & remote_ctx->watcher); } if (remote_ctx == NULL) { if (verbose) { #ifdef MODULE_REDIR char src[SS_ADDRSTRLEN]; char dst[SS_ADDRSTRLEN]; strcpy(src, get_addr_str((struct sockaddr *)&src_addr)); strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr)); LOGI("[udp] cache miss: %s <-> %s", dst, src); #else LOGI("[udp] cache miss: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); #endif } } else { if (verbose) { #ifdef MODULE_REDIR char src[SS_ADDRSTRLEN]; char dst[SS_ADDRSTRLEN]; strcpy(src, get_addr_str((struct sockaddr *)&src_addr)); strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr)); LOGI("[udp] cache hit: %s <-> %s", dst, src); #else LOGI("[udp] cache hit: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); #endif } } #ifdef MODULE_LOCAL #if !defined(MODULE_TUNNEL) && !defined(MODULE_REDIR) if (frag) { LOGE("[udp] drop a message since frag is not 0, but %d", frag); goto CLEAN_UP; } #endif const struct sockaddr *remote_addr = server_ctx->remote_addr; const int remote_addr_len = server_ctx->remote_addr_len; if (remote_ctx == NULL) { // Bind to any port int remotefd = create_remote_socket(remote_addr->sa_family == AF_INET6); if (remotefd < 0) { ERROR("[udp] udprelay bind() error"); goto CLEAN_UP; } setnonblocking(remotefd); #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef IP_TOS // Set QoS flag int tos = 46; setsockopt(remotefd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); #endif #ifdef SET_INTERFACE if (server_ctx->iface) { if (setinterface(remotefd, server_ctx->iface) == -1) ERROR("setinterface"); } #endif #ifdef __ANDROID__ if (vpn) { if (protect_socket(remotefd) == -1) { ERROR("protect_socket"); close(remotefd); goto CLEAN_UP; } } #endif // Init remote_ctx remote_ctx = new_remote(remotefd, server_ctx); remote_ctx->src_addr = src_addr; remote_ctx->af = remote_addr->sa_family; remote_ctx->addr_header_len = addr_header_len; memcpy(remote_ctx->addr_header, addr_header, addr_header_len); // Add to conn cache cache_insert(conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx); // Start remote io ev_io_start(EV_A_ & remote_ctx->io); ev_timer_start(EV_A_ & remote_ctx->watcher); } if (offset > 0) { buf->len -= offset; memmove(buf->data, buf->data + offset, buf->len); } int err = server_ctx->crypto->encrypt_all(buf, server_ctx->crypto->cipher, buf_size); if (err) { // drop the packet silently goto CLEAN_UP; } if (buf->len > packet_size) { if (verbose) { LOGI("[udp] server_recv_sendto fragmentation"); } } int s = sendto(remote_ctx->fd, buf->data, buf->len, 0, remote_addr, remote_addr_len); if (s == -1) { ERROR("[udp] server_recv_sendto"); } #else int cache_hit = 0; int need_query = 0; if (buf->len - addr_header_len > packet_size) { if (verbose) { LOGI("[udp] server_recv_sendto fragmentation"); } } if (remote_ctx != NULL) { cache_hit = 1; // detect destination mismatch if (remote_ctx->addr_header_len != addr_header_len || memcmp(addr_header, remote_ctx->addr_header, addr_header_len) != 0) { if (dst_addr.ss_family != AF_INET && dst_addr.ss_family != AF_INET6) { need_query = 1; } } else { memcpy(&dst_addr, &remote_ctx->dst_addr, sizeof(struct sockaddr_storage)); } } else { if (dst_addr.ss_family == AF_INET || dst_addr.ss_family == AF_INET6) { int remotefd = create_remote_socket(dst_addr.ss_family == AF_INET6); if (remotefd != -1) { setnonblocking(remotefd); #ifdef SO_BROADCAST set_broadcast(remotefd); #endif #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef IP_TOS // Set QoS flag int tos = 46; setsockopt(remotefd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); #endif #ifdef SET_INTERFACE if (server_ctx->iface) { if (setinterface(remotefd, server_ctx->iface) == -1) ERROR("setinterface"); } #endif remote_ctx = new_remote(remotefd, server_ctx); remote_ctx->src_addr = src_addr; remote_ctx->server_ctx = server_ctx; remote_ctx->addr_header_len = addr_header_len; memcpy(remote_ctx->addr_header, addr_header, addr_header_len); memcpy(&remote_ctx->dst_addr, &dst_addr, sizeof(struct sockaddr_storage)); } else { ERROR("[udp] bind() error"); goto CLEAN_UP; } } } if (remote_ctx != NULL && !need_query) { size_t addr_len = get_sockaddr_len((struct sockaddr *)&dst_addr); int s = sendto(remote_ctx->fd, buf->data + addr_header_len, buf->len - addr_header_len, 0, (struct sockaddr *)&dst_addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); if (!cache_hit) { close_and_free_remote(EV_A_ remote_ctx); } } else { if (!cache_hit) { // Add to conn cache remote_ctx->af = dst_addr.ss_family; char *key = hash_key(remote_ctx->af, &remote_ctx->src_addr); cache_insert(server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx); ev_io_start(EV_A_ & remote_ctx->io); ev_timer_start(EV_A_ & remote_ctx->watcher); } } } else { struct addrinfo hints; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_protocol = IPPROTO_UDP; struct query_ctx *query_ctx = new_query_ctx(buf->data + addr_header_len, buf->len - addr_header_len); query_ctx->server_ctx = server_ctx; query_ctx->addr_header_len = addr_header_len; query_ctx->src_addr = src_addr; memcpy(query_ctx->addr_header, addr_header, addr_header_len); if (need_query) { query_ctx->remote_ctx = remote_ctx; } struct ResolvQuery *query = resolv_query(host, query_resolve_cb, NULL, query_ctx, htons(atoi(port))); if (query == NULL) { ERROR("[udp] unable to create DNS query"); close_and_free_query(EV_A_ query_ctx); goto CLEAN_UP; } query_ctx->query = query; } #endif CLEAN_UP: bfree(buf); ss_free(buf); }
static void query_resolve_cb(struct sockaddr *addr, void *data) { struct query_ctx *query_ctx = (struct query_ctx *)data; struct ev_loop *loop = query_ctx->server_ctx->loop; if (verbose) { LOGI("[udp] udns resolved"); } query_ctx->query = NULL; if (addr == NULL) { LOGE("[udp] udns returned an error"); } else { remote_ctx_t *remote_ctx = query_ctx->remote_ctx; int cache_hit = 0; // Lookup in the conn cache if (remote_ctx == NULL) { char *key = hash_key(AF_UNSPEC, &query_ctx->src_addr); cache_lookup(query_ctx->server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)&remote_ctx); } if (remote_ctx == NULL) { int remotefd = create_remote_socket(addr->sa_family == AF_INET6); if (remotefd != -1) { setnonblocking(remotefd); #ifdef SO_BROADCAST set_broadcast(remotefd); #endif #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef IP_TOS // Set QoS flag int tos = 46; setsockopt(remotefd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); #endif #ifdef SET_INTERFACE if (query_ctx->server_ctx->iface) { if (setinterface(remotefd, query_ctx->server_ctx->iface) == -1) ERROR("setinterface"); } #endif remote_ctx = new_remote(remotefd, query_ctx->server_ctx); remote_ctx->src_addr = query_ctx->src_addr; remote_ctx->server_ctx = query_ctx->server_ctx; remote_ctx->addr_header_len = query_ctx->addr_header_len; memcpy(remote_ctx->addr_header, query_ctx->addr_header, query_ctx->addr_header_len); } else { ERROR("[udp] bind() error"); } } else { cache_hit = 1; } if (remote_ctx != NULL) { memcpy(&remote_ctx->dst_addr, addr, sizeof(struct sockaddr_storage)); size_t addr_len = get_sockaddr_len(addr); int s = sendto(remote_ctx->fd, query_ctx->buf->data, query_ctx->buf->len, 0, addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); if (!cache_hit) { close_and_free_remote(EV_A_ remote_ctx); } } else { if (!cache_hit) { // Add to conn cache char *key = hash_key(AF_UNSPEC, &remote_ctx->src_addr); cache_insert(query_ctx->server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx); ev_io_start(EV_A_ & remote_ctx->io); ev_timer_start(EV_A_ & remote_ctx->watcher); } } } } // clean up close_and_free_query(EV_A_ query_ctx); }
int create_server_socket(const char *host, const char *port) { struct addrinfo hints; struct addrinfo *result, *rp, *ipv4v6bindall; int s, server_sock; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = AF_UNSPEC; /* Return IPv4 and IPv6 choices */ hints.ai_socktype = SOCK_DGRAM; /* We want a UDP socket */ hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; /* For wildcard IP address */ hints.ai_protocol = IPPROTO_UDP; s = getaddrinfo(host, port, &hints, &result); if (s != 0) { LOGE("[udp] getaddrinfo: %s", gai_strerror(s)); return -1; } if (result == NULL) { LOGE("[udp] cannot bind"); return -1; } rp = result; /* * On Linux, with net.ipv6.bindv6only = 0 (the default), getaddrinfo(NULL) with * AI_PASSIVE returns 0.0.0.0 and :: (in this order). AI_PASSIVE was meant to * return a list of addresses to listen on, but it is impossible to listen on * 0.0.0.0 and :: at the same time, if :: implies dualstack mode. */ if (!host) { ipv4v6bindall = result; /* Loop over all address infos found until a IPV6 address is found. */ while (ipv4v6bindall) { if (ipv4v6bindall->ai_family == AF_INET6) { rp = ipv4v6bindall; /* Take first IPV6 address available */ break; } ipv4v6bindall = ipv4v6bindall->ai_next; /* Get next address info, if any */ } } for (/*rp = result*/; rp != NULL; rp = rp->ai_next) { server_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (server_sock == -1) { continue; } if (rp->ai_family == AF_INET6) { int ipv6only = host ? 1 : 0; setsockopt(server_sock, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6only, sizeof(ipv6only)); } int opt = 1; setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); #ifdef SO_NOSIGPIPE set_nosigpipe(server_sock); #endif if (reuse_port) { int err = set_reuseport(server_sock); if (err == 0) { LOGI("udp port reuse enabled"); } } #ifdef IP_TOS // Set QoS flag int tos = 46; setsockopt(server_sock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); #endif #ifdef MODULE_REDIR if (setsockopt(server_sock, SOL_IP, IP_TRANSPARENT, &opt, sizeof(opt))) { ERROR("[udp] setsockopt IP_TRANSPARENT"); exit(EXIT_FAILURE); } if (rp->ai_family == AF_INET) { if (setsockopt(server_sock, SOL_IP, IP_RECVORIGDSTADDR, &opt, sizeof(opt))) { FATAL("[udp] setsockopt IP_RECVORIGDSTADDR"); } } else if (rp->ai_family == AF_INET6) { if (setsockopt(server_sock, SOL_IPV6, IPV6_RECVORIGDSTADDR, &opt, sizeof(opt))) { FATAL("[udp] setsockopt IPV6_RECVORIGDSTADDR"); } } #endif s = bind(server_sock, rp->ai_addr, rp->ai_addrlen); if (s == 0) { /* We managed to bind successfully! */ break; } else { ERROR("[udp] bind"); } close(server_sock); server_sock = -1; } freeaddrinfo(result); return server_sock; }
void slimproto(log_level level, in_addr_t addr, u8_t mac[6], const char *name) { struct sockaddr_in serv_addr; static char fixed_cap[128], var_cap[128] = ""; bool reconnect = false; int i; wake_create(wake_e); loglevel = level; running = true; slimproto_ip = addr ? addr : discover_server(); if (!running) return; LOCK_O; sprintf(fixed_cap, ",MaxSampleRate=%u", output.max_sample_rate); for (i = 0; i < MAX_CODECS; i++) { if (codecs[i] && codecs[i]->id && strlen(fixed_cap) < 128 - 10) { strcat(fixed_cap, ","); strcat(fixed_cap, codecs[i]->types); } } UNLOCK_O; memset(&serv_addr, 0, sizeof(serv_addr)); serv_addr.sin_family = AF_INET; serv_addr.sin_addr.s_addr = slimproto_ip; serv_addr.sin_port = htons(PORT); LOG_INFO("connecting to %s:%d", inet_ntoa(serv_addr.sin_addr), ntohs(serv_addr.sin_port)); new_server = 0; while (running) { if (new_server) { slimproto_ip = serv_addr.sin_addr.s_addr = new_server; LOG_INFO("switching server to %s:%d", inet_ntoa(serv_addr.sin_addr), ntohs(serv_addr.sin_port)); new_server = 0; reconnect = false; } sock = socket(AF_INET, SOCK_STREAM, 0); if (connect(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) { LOG_INFO("unable to connect to server"); sleep(5); } else { LOG_INFO("connected"); set_nosigpipe(sock); var_cap[0] = '\0'; #if !WIN // check if this is a local player now we are connected & signal to server via 'loc' format // this requires LocalPlayer server plugin to enable direct file access // not supported on windows at present as the poll in stream.c does not work for file access struct sockaddr_in our_addr; socklen_t len; len = sizeof(our_addr); getsockname(sock, (struct sockaddr *) &our_addr, &len); if (our_addr.sin_addr.s_addr == serv_addr.sin_addr.s_addr) { LOG_INFO("local player"); strcat(var_cap, ",loc"); } #endif // add on any capablity to be sent to the new server if (new_server_cap) { strcat(var_cap, new_server_cap); free(new_server_cap); new_server_cap = NULL; } sendHELO(reconnect, fixed_cap, var_cap, mac); if (name) { sendSETDName(name); name = NULL; } slimproto_run(); if (!reconnect) { reconnect = true; } usleep(100000); } closesocket(sock); } }
static void server_recv_cb(EV_P_ ev_io *w, int revents) { struct server_ctx *server_ctx = (struct server_ctx *)w; struct sockaddr_storage src_addr; memset(&src_addr, 0, sizeof(struct sockaddr_storage)); char *buf = malloc(BUF_SIZE); socklen_t src_addr_len = sizeof(struct sockaddr_storage); unsigned int offset = 0; #ifdef UDPRELAY_REDIR char control_buffer[64] = { 0 }; struct msghdr msg; struct iovec iov[1]; struct sockaddr_storage dst_addr; memset(&dst_addr, 0, sizeof(struct sockaddr_storage)); msg.msg_name = &src_addr; msg.msg_namelen = src_addr_len; msg.msg_control = control_buffer; msg.msg_controllen = sizeof(control_buffer); iov[0].iov_base = buf; iov[0].iov_len = BUF_SIZE; msg.msg_iov = iov; msg.msg_iovlen = 1; ssize_t buf_len = recvmsg(server_ctx->fd, &msg, 0); if (buf_len == -1) { ERROR("[udp] server_recvmsg"); goto CLEAN_UP; } if (get_dstaddr(&msg, &dst_addr)) { LOGE("[udp] unable to get dest addr"); goto CLEAN_UP; } src_addr_len = msg.msg_namelen; #else ssize_t buf_len = recvfrom(server_ctx->fd, buf, BUF_SIZE, 0, (struct sockaddr *)&src_addr, &src_addr_len); if (buf_len == -1) { // error on recv // simply drop that packet ERROR("[udp] server_recvfrom"); goto CLEAN_UP; } #endif if (verbose) { LOGI("[udp] server receive a packet"); } #ifdef UDPRELAY_REMOTE tx += buf_len; buf = ss_decrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method, server_ctx->auth); if (buf == NULL) { ERROR("[udp] server_ss_decrypt_all"); goto CLEAN_UP; } #endif #ifdef UDPRELAY_LOCAL #if !defined(UDPRELAY_TUNNEL) && !defined(UDPRELAY_REDIR) uint8_t frag = *(uint8_t *)(buf + 2); offset += 3; #endif #endif // packet size > default MTU if (verbose && buf_len > MTU) { LOGE("[udp] possible ip fragment, size: %d", (int)buf_len); } /* * * SOCKS5 UDP Request * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * SOCKS5 UDP Response * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * shadowsocks UDP Request (before encrypted) * +------+----------+----------+----------+-------------+ * | ATYP | DST.ADDR | DST.PORT | DATA | HMAC-SHA1 | * +------+----------+----------+----------+-------------+ * | 1 | Variable | 2 | Variable | 10 | * +------+----------+----------+----------+-------------+ * * If ATYP & ONETIMEAUTH_FLAG(0x10) == 1, Authentication (HMAC-SHA1) is enabled. * * The key of HMAC-SHA1 is (IV + KEY) and the input is the whole packet. * The output of HMAC-SHA is truncated to 10 bytes (leftmost bits). * * shadowsocks UDP Response (before encrypted) * +------+----------+----------+----------+ * | ATYP | DST.ADDR | DST.PORT | DATA | * +------+----------+----------+----------+ * | 1 | Variable | 2 | Variable | * +------+----------+----------+----------+ * * shadowsocks UDP Request and Response (after encrypted) * +-------+--------------+ * | IV | PAYLOAD | * +-------+--------------+ * | Fixed | Variable | * +-------+--------------+ * */ #ifdef UDPRELAY_REDIR char addr_header[256] = { 0 }; int addr_header_len = construct_udprealy_header(&dst_addr, addr_header); if (addr_header_len == 0) { LOGE("[udp] failed to parse tproxy addr"); goto CLEAN_UP; } // reconstruct the buffer if (BUF_SIZE < buf_len + addr_header_len) { buf = realloc(buf, buf_len + addr_header_len); } memmove(buf + addr_header_len, buf, buf_len); memcpy(buf, addr_header, addr_header_len); buf_len += addr_header_len; char *key = hash_key(dst_addr.ss_family, &src_addr); #elif UDPRELAY_TUNNEL char addr_header[256] = { 0 }; char *host = server_ctx->tunnel_addr.host; char *port = server_ctx->tunnel_addr.port; uint16_t port_num = (uint16_t)atoi(port); uint16_t port_net_num = htons(port_num); int addr_header_len = 0; struct cork_ip ip; if (cork_ip_init(&ip, host) != -1) { if (ip.version == 4) { // send as IPv4 struct in_addr host_addr; int host_len = sizeof(struct in_addr); if (dns_pton(AF_INET, host, &host_addr) == -1) { FATAL("IP parser error"); } addr_header[addr_header_len++] = 1; memcpy(addr_header + addr_header_len, &host_addr, host_len); addr_header_len += host_len; } else if (ip.version == 6) { // send as IPv6 struct in6_addr host_addr; int host_len = sizeof(struct in6_addr); if (dns_pton(AF_INET6, host, &host_addr) == -1) { FATAL("IP parser error"); } addr_header[addr_header_len++] = 4; memcpy(addr_header + addr_header_len, &host_addr, host_len); addr_header_len += host_len; } else { FATAL("IP parser error"); } } else { // send as domain int host_len = strlen(host); addr_header[addr_header_len++] = 3; addr_header[addr_header_len++] = host_len; memcpy(addr_header + addr_header_len, host, host_len); addr_header_len += host_len; } memcpy(addr_header + addr_header_len, &port_net_num, 2); addr_header_len += 2; // reconstruct the buffer if (BUF_SIZE < buf_len + addr_header_len) { buf = realloc(buf, buf_len + addr_header_len); } memmove(buf + addr_header_len, buf, buf_len); memcpy(buf, addr_header, addr_header_len); buf_len += addr_header_len; char *key = hash_key(ip.version == 4 ? AF_INET : AF_INET6, &src_addr); #else char host[256] = { 0 }; char port[64] = { 0 }; struct sockaddr_storage dst_addr; memset(&dst_addr, 0, sizeof(struct sockaddr_storage)); int addr_header_len = parse_udprealy_header(buf + offset, buf_len - offset, &server_ctx->auth, host, port, &dst_addr); if (addr_header_len == 0) { // error in parse header goto CLEAN_UP; } char *addr_header = buf + offset; char *key = hash_key(dst_addr.ss_family, &src_addr); #endif struct cache *conn_cache = server_ctx->conn_cache; struct remote_ctx *remote_ctx = NULL; cache_lookup(conn_cache, key, HASH_KEY_LEN, (void *)&remote_ctx); if (remote_ctx != NULL) { if (memcmp(&src_addr, &remote_ctx->src_addr, sizeof(src_addr))) { remote_ctx = NULL; } } // reset the timer if (remote_ctx != NULL) { ev_timer_again(EV_A_ & remote_ctx->watcher); } if (remote_ctx == NULL) { if (verbose) { #ifdef UDPRELAY_REDIR char src[SS_ADDRSTRLEN]; char dst[SS_ADDRSTRLEN]; strcpy(src, get_addr_str((struct sockaddr *)&src_addr)); strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr)); LOGI("[udp] cache miss: %s <-> %s", dst, src); #else LOGI("[udp] cache miss: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); #endif } } else { if (verbose) { #ifdef UDPRELAY_REDIR char src[SS_ADDRSTRLEN]; char dst[SS_ADDRSTRLEN]; strcpy(src, get_addr_str((struct sockaddr *)&src_addr)); strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr)); LOGI("[udp] cache hit: %s <-> %s", dst, src); #else LOGI("[udp] cache hit: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); #endif } } #ifdef UDPRELAY_LOCAL #if !defined(UDPRELAY_TUNNEL) && !defined(UDPRELAY_REDIR) if (frag) { LOGE("[udp] drop a message since frag is not 0, but %d", frag); goto CLEAN_UP; } #endif const struct sockaddr *remote_addr = server_ctx->remote_addr; const int remote_addr_len = server_ctx->remote_addr_len; if (remote_ctx == NULL) { // Bind to any port int remotefd = create_remote_socket(remote_addr->sa_family == AF_INET6); if (remotefd < 0) { ERROR("[udp] udprelay bind() error"); goto CLEAN_UP; } setnonblocking(remotefd); #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef SET_INTERFACE if (server_ctx->iface) { setinterface(remotefd, server_ctx->iface); } #endif #ifdef ANDROID if (vpn) { if (protect_socket(remotefd) == -1) { ERROR("protect_socket"); close(remotefd); goto CLEAN_UP; } } #endif // Init remote_ctx remote_ctx = new_remote(remotefd, server_ctx); remote_ctx->src_addr = src_addr; remote_ctx->af = remote_addr->sa_family; remote_ctx->addr_header_len = addr_header_len; memcpy(remote_ctx->addr_header, addr_header, addr_header_len); // Add to conn cache cache_insert(conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx); // Start remote io ev_io_start(EV_A_ & remote_ctx->io); ev_timer_start(EV_A_ & remote_ctx->watcher); } if (offset > 0) { buf_len -= offset; memmove(buf, buf + offset, buf_len); } if (server_ctx->auth) { buf[0] |= ONETIMEAUTH_FLAG; } buf = ss_encrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method, server_ctx->auth); int s = sendto(remote_ctx->fd, buf, buf_len, 0, remote_addr, remote_addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); } #else int cache_hit = 0; int need_query = 0; if (remote_ctx != NULL) { cache_hit = 1; // detect destination mismatch if (remote_ctx->addr_header_len != addr_header_len || memcmp(addr_header, remote_ctx->addr_header, addr_header_len) != 0) { if (dst_addr.ss_family != AF_INET && dst_addr.ss_family != AF_INET6) { need_query = 1; } } } else { if (dst_addr.ss_family == AF_INET || dst_addr.ss_family == AF_INET6) { int remotefd = create_remote_socket(dst_addr.ss_family == AF_INET6); if (remotefd != -1) { setnonblocking(remotefd); #ifdef SO_BROADCAST set_broadcast(remotefd); #endif #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef SET_INTERFACE if (server_ctx->iface) { setinterface(remotefd, server_ctx->iface); } #endif remote_ctx = new_remote(remotefd, server_ctx); remote_ctx->src_addr = src_addr; remote_ctx->server_ctx = server_ctx; remote_ctx->addr_header_len = addr_header_len; memcpy(remote_ctx->addr_header, addr_header, addr_header_len); } else { ERROR("[udp] bind() error"); goto CLEAN_UP; } } } if (remote_ctx != NULL && !need_query) { size_t addr_len = get_sockaddr_len((struct sockaddr *)&dst_addr); int s = sendto(remote_ctx->fd, buf + addr_header_len, buf_len - addr_header_len, 0, (struct sockaddr *)&dst_addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); if (!cache_hit) { close_and_free_remote(EV_A_ remote_ctx); } } else { if (!cache_hit) { // Add to conn cache remote_ctx->af = dst_addr.ss_family; char *key = hash_key(remote_ctx->af, &remote_ctx->src_addr); cache_insert(server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx); ev_io_start(EV_A_ & remote_ctx->io); ev_timer_start(EV_A_ & remote_ctx->watcher); } } } else { struct addrinfo hints; memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_protocol = IPPROTO_UDP; struct query_ctx *query_ctx = new_query_ctx(buf + addr_header_len, buf_len - addr_header_len); query_ctx->server_ctx = server_ctx; query_ctx->addr_header_len = addr_header_len; query_ctx->src_addr = src_addr; memcpy(query_ctx->addr_header, addr_header, addr_header_len); if (need_query) { query_ctx->remote_ctx = remote_ctx; } struct ResolvQuery *query = resolv_query(host, query_resolve_cb, NULL, query_ctx, htons(atoi(port))); if (query == NULL) { ERROR("[udp] unable to create DNS query"); close_and_free_query(EV_A_ query_ctx); goto CLEAN_UP; } query_ctx->query = query; } #endif CLEAN_UP: free(buf); }
static void server_recv_cb(EV_P_ ev_io *w, int revents) { struct server_ctx *server_ctx = (struct server_ctx *)w; struct sockaddr_storage src_addr; char *buf = malloc(BUF_SIZE); socklen_t src_addr_len = sizeof(struct sockaddr_storage); unsigned int offset = 0; ssize_t buf_len = recvfrom(server_ctx->fd, buf, BUF_SIZE, 0, (struct sockaddr *)&src_addr, &src_addr_len); if (buf_len == -1) { // error on recv // simply drop that packet if (verbose) { ERROR("[udp] server_recvfrom"); } goto CLEAN_UP; } if (verbose) { LOGD("[udp] server receive a packet."); } #ifdef UDPRELAY_REMOTE buf = ss_decrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method); if (buf == NULL) { if (verbose) { ERROR("[udp] server_ss_decrypt_all"); } goto CLEAN_UP; } #endif #ifdef UDPRELAY_LOCAL #ifndef UDPRELAY_TUNNEL uint8_t frag = *(uint8_t *)(buf + 2); offset += 3; #endif #endif /* * * SOCKS5 UDP Request * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * SOCKS5 UDP Response * +----+------+------+----------+----------+----------+ * |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA | * +----+------+------+----------+----------+----------+ * | 2 | 1 | 1 | Variable | 2 | Variable | * +----+------+------+----------+----------+----------+ * * shadowsocks UDP Request (before encrypted) * +------+----------+----------+----------+ * | ATYP | DST.ADDR | DST.PORT | DATA | * +------+----------+----------+----------+ * | 1 | Variable | 2 | Variable | * +------+----------+----------+----------+ * * shadowsocks UDP Response (before encrypted) * +------+----------+----------+----------+ * | ATYP | DST.ADDR | DST.PORT | DATA | * +------+----------+----------+----------+ * | 1 | Variable | 2 | Variable | * +------+----------+----------+----------+ * * shadowsocks UDP Request and Response (after encrypted) * +-------+--------------+ * | IV | PAYLOAD | * +-------+--------------+ * | Fixed | Variable | * +-------+--------------+ * */ #ifdef UDPRELAY_TUNNEL char addr_header[256] = { 0 }; char * host = server_ctx->tunnel_addr.host; char * port = server_ctx->tunnel_addr.port; int host_len = strlen(host); uint16_t port_num = (uint16_t)atoi(port); uint16_t port_net_num = htons(port_num); int addr_header_len = 2 + host_len + 2; // initialize the addr header addr_header[0] = 3; addr_header[1] = host_len; memcpy(addr_header + 2, host, host_len); memcpy(addr_header + 2 + host_len, &port_net_num, 2); // reconstruct the buffer char *tmp = malloc(buf_len + addr_header_len); memcpy(tmp, addr_header, addr_header_len); memcpy(tmp + addr_header_len, buf, buf_len); free(buf); buf = tmp; buf_len += addr_header_len; #else char host[256] = { 0 }; char port[64] = { 0 }; int addr_header_len = parse_udprealy_header(buf + offset, buf_len - offset, host, port); if (addr_header_len == 0) { // error in parse header goto CLEAN_UP; } char *addr_header = buf + offset; #endif char *key = hash_key(addr_header, addr_header_len, &src_addr); struct cache *conn_cache = server_ctx->conn_cache; struct remote_ctx *remote_ctx = NULL; cache_lookup(conn_cache, key, (void *)&remote_ctx); if (remote_ctx != NULL) { if (memcmp(&src_addr, &remote_ctx->src_addr, sizeof(src_addr)) || strcmp(addr_header, remote_ctx->addr_header) != 0) { remote_ctx = NULL; } } if (remote_ctx == NULL) { if (verbose) { LOGD("[udp] cache missed: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); } } else { if (verbose) { LOGD("[udp] cache hit: %s:%s <-> %s", host, port, get_addr_str((struct sockaddr *)&src_addr)); } } #ifdef UDPRELAY_LOCAL #ifndef UDPRELAY_TUNNEL if (frag) { LOGE("[udp] drop a message since frag is not 0, but %d", frag); goto CLEAN_UP; } #endif if (remote_ctx == NULL) { struct addrinfo hints; struct addrinfo *result; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = AF_UNSPEC; /* Return IPv4 and IPv6 choices */ hints.ai_socktype = SOCK_DGRAM; /* We want a UDP socket */ int s = getaddrinfo(server_ctx->remote_host, server_ctx->remote_port, &hints, &result); if (s != 0 || result == NULL) { LOGE("[udp] getaddrinfo: %s", gai_strerror(s)); goto CLEAN_UP; } // Bind to any port int remotefd = create_remote_socket(result->ai_family == AF_INET6); if (remotefd < 0) { ERROR("[udp] udprelay bind() error.."); // remember to free addrinfo freeaddrinfo(result); goto CLEAN_UP; } setnonblocking(remotefd); #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef SET_INTERFACE if (server_ctx->iface) { setinterface(remotefd, server_ctx->iface); } #endif // Init remote_ctx remote_ctx = new_remote(remotefd, server_ctx); remote_ctx->src_addr = src_addr; remote_ctx->dst_addr = *((struct sockaddr_storage *)result->ai_addr); remote_ctx->addr_header_len = addr_header_len; memcpy(remote_ctx->addr_header, addr_header, addr_header_len); // Add to conn cache cache_insert(conn_cache, key, (void *)remote_ctx); // Start remote io ev_io_start(EV_A_ & remote_ctx->io); // clean up freeaddrinfo(result); } if (offset > 0) { buf_len -= offset; memmove(buf, buf + offset, buf_len); } buf = ss_encrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method); size_t addr_len = sizeof(struct sockaddr_in); if (remote_ctx->dst_addr.ss_family == AF_INET6) { addr_len = sizeof(struct sockaddr_in6); } int s = sendto(remote_ctx->fd, buf, buf_len, 0, (struct sockaddr *)&remote_ctx->dst_addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); } #else if (remote_ctx == NULL) { struct addrinfo hints; asyncns_query_t *query; memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; query = asyncns_getaddrinfo(server_ctx->asyncns, host, port, &hints); if (query == NULL) { ERROR("[udp] asyncns_getaddrinfo"); goto CLEAN_UP; } struct query_ctx *query_ctx = new_query_ctx(query, buf + addr_header_len, buf_len - addr_header_len); query_ctx->server_ctx = server_ctx; query_ctx->addr_header_len = addr_header_len; query_ctx->src_addr = src_addr; memcpy(query_ctx->addr_header, addr_header, addr_header_len); asyncns_setuserdata(server_ctx->asyncns, query, query_ctx); } else { size_t addr_len = sizeof(struct sockaddr_in); if (remote_ctx->dst_addr.ss_family == AF_INET6) { addr_len = sizeof(struct sockaddr_in6); } int s = sendto(remote_ctx->fd, buf + addr_header_len, buf_len - addr_header_len, 0, (struct sockaddr *)&remote_ctx->dst_addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); } } #endif CLEAN_UP: free(buf); }
static void query_resolve_cb(EV_P_ ev_io *w, int revents) { int err; struct addrinfo *result, *rp; struct resolve_ctx *resolve_ctx = (struct resolve_ctx *)w; asyncns_t *asyncns = resolve_ctx->asyncns; err = asyncns_handle(asyncns); if (err == ASYNCNS_HANDLE_AGAIN) { // try again return; } else if (err == ASYNCNS_HANDLE_ERROR) { // asyncns error FATAL("[udp] asyncns exit unexpectedly."); } asyncns_query_t *query = asyncns_getnext(asyncns); struct query_ctx *query_ctx = (struct query_ctx *)asyncns_getuserdata( asyncns, query); if (!asyncns_isdone(asyncns, query)) { // wait reolver return; } if (verbose) { LOGD("[udp] asyncns resolved."); } query_ctx->query = NULL; err = asyncns_getaddrinfo_done(asyncns, query, &result); if (err) { ERROR("[udp] asysncns_getaddrinfo"); } else { // Use IPV4 address if possible for (rp = result; rp != NULL; rp = rp->ai_next) { if (rp->ai_family == AF_INET) { break; } } if (rp == NULL) { rp = result; } int remotefd = create_remote_socket(rp->ai_family == AF_INET6); if (remotefd != -1) { setnonblocking(remotefd); #ifdef SO_BROADCAST set_broadcast(remotefd); #endif #ifdef SO_NOSIGPIPE set_nosigpipe(remotefd); #endif #ifdef SET_INTERFACE if (query_ctx->server_ctx->iface) { setinterface(remotefd, query_ctx->server_ctx->iface); } #endif struct remote_ctx *remote_ctx = new_remote(remotefd, query_ctx->server_ctx); remote_ctx->src_addr = query_ctx->src_addr; remote_ctx->dst_addr = *((struct sockaddr_storage *)rp->ai_addr); remote_ctx->server_ctx = query_ctx->server_ctx; remote_ctx->addr_header_len = query_ctx->addr_header_len; memcpy(remote_ctx->addr_header, query_ctx->addr_header, query_ctx->addr_header_len); size_t addr_len = sizeof(struct sockaddr_in); if (remote_ctx->dst_addr.ss_family == AF_INET6) { addr_len = sizeof(struct sockaddr_in6); } int s = sendto(remote_ctx->fd, query_ctx->buf, query_ctx->buf_len, 0, (struct sockaddr *)&remote_ctx->dst_addr, addr_len); if (s == -1) { ERROR("[udp] sendto_remote"); close_and_free_remote(EV_A_ remote_ctx); } else { // Add to conn cache char *key = hash_key(remote_ctx->addr_header, remote_ctx->addr_header_len, &remote_ctx->src_addr); cache_insert(query_ctx->server_ctx->conn_cache, key, (void *)remote_ctx); ev_io_start(EV_A_ & remote_ctx->io); } } else { ERROR("[udp] bind() error.."); } } // clean up asyncns_freeaddrinfo(result); close_and_free_query(EV_A_ query_ctx); }