From 543a5ecbb12d13350a345044632a6b6d04f3d640 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Tue, 11 Feb 2020 21:37:33 +0100 Subject: [PATCH] Move join state out of meshlink_handle_t, and ensure proper cleanup on errors. Move the state we keep when calling meshlink_join() out of meshlink_handle_t and just put it on the stack of meshlink_join(). Also make sure we properly release allocated resources in all error conditions during a join. --- src/meshlink.c | 201 ++++++++++++++++++++++------------------ src/meshlink_internal.h | 11 --- 2 files changed, 111 insertions(+), 101 deletions(-) diff --git a/src/meshlink.c b/src/meshlink.c index 5b01ad2c..eb9142cc 100644 --- a/src/meshlink.c +++ b/src/meshlink.c @@ -609,7 +609,22 @@ static bool write_main_config_files(meshlink_handle_t *mesh) { return true; } -static bool finalize_join(meshlink_handle_t *mesh, const void *buf, uint16_t len) { +typedef struct { + meshlink_handle_t *mesh; + int sock; + char cookie[18 + 32]; + char hash[18]; + bool success; + sptps_t sptps; + char *data; + size_t thedatalen; + size_t blen; + char line[4096]; + char buffer[4096]; +} join_state_t; + +static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) { + meshlink_handle_t *mesh = state->mesh; packmsg_input_t in = {buf, len}; uint32_t version = packmsg_get_uint32(&in); @@ -706,7 +721,7 @@ static bool finalize_join(meshlink_handle_t *mesh, const void *buf, uint16_t len sockaddr_t sa; socklen_t salen = sizeof(sa); - if(getpeername(mesh->sock, &sa.sa, &salen) == 0) { + if(getpeername(state->sock, &sa.sa, &salen) == 0) { node_add_recent_address(mesh, n, &sa); } } @@ -728,7 +743,7 @@ static bool finalize_join(meshlink_handle_t *mesh, const void *buf, uint16_t len return false; } - sptps_send_record(&mesh->sptps, 1, ecdsa_get_public_key(mesh->private_key), 32); + sptps_send_record(&state->sptps, 1, ecdsa_get_public_key(mesh->private_key), 32); logger(mesh, MESHLINK_DEBUG, "Configuration stored in: %s\n", mesh->confbase); @@ -737,11 +752,11 @@ static bool finalize_join(meshlink_handle_t *mesh, const void *buf, uint16_t len static bool invitation_send(void *handle, uint8_t type, const void *data, size_t len) { (void)type; - meshlink_handle_t *mesh = handle; + join_state_t *state = handle; const char *ptr = data; while(len) { - int result = send(mesh->sock, ptr, len, 0); + int result = send(state->sock, ptr, len, 0); if(result == -1 && errno == EINTR) { continue; @@ -757,19 +772,20 @@ static bool invitation_send(void *handle, uint8_t type, const void *data, size_t } static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint16_t len) { - meshlink_handle_t *mesh = handle; + join_state_t *state = handle; + meshlink_handle_t *mesh = state->mesh; switch(type) { case SPTPS_HANDSHAKE: - return sptps_send_record(&mesh->sptps, 0, mesh->cookie, sizeof(mesh)->cookie); + return sptps_send_record(&state->sptps, 0, state->cookie, 18); case 0: - return finalize_join(mesh, msg, len); + return finalize_join(state, msg, len); case 1: logger(mesh, MESHLINK_DEBUG, "Invitation successfully accepted.\n"); - shutdown(mesh->sock, SHUT_RDWR); - mesh->success = true; + shutdown(state->sock, SHUT_RDWR); + state->success = true; break; default: @@ -779,15 +795,11 @@ static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint return true; } -static bool recvline(meshlink_handle_t *mesh, size_t len) { +static bool recvline(join_state_t *state) { char *newline = NULL; - if(!mesh->sock) { - abort(); - } - - while(!(newline = memchr(mesh->buffer, '\n', mesh->blen))) { - int result = recv(mesh->sock, mesh->buffer + mesh->blen, sizeof(mesh)->buffer - mesh->blen, 0); + while(!(newline = memchr(state->buffer, '\n', state->blen))) { + int result = recv(state->sock, state->buffer + state->blen, sizeof(state)->buffer - state->blen, 0); if(result == -1 && errno == EINTR) { continue; @@ -795,19 +807,19 @@ static bool recvline(meshlink_handle_t *mesh, size_t len) { return false; } - mesh->blen += result; + state->blen += result; } - if((size_t)(newline - mesh->buffer) >= len) { + if((size_t)(newline - state->buffer) >= sizeof(state->line)) { return false; } - len = newline - mesh->buffer; + size_t len = newline - state->buffer; - memcpy(mesh->line, mesh->buffer, len); - mesh->line[len] = 0; - memmove(mesh->buffer, newline + 1, mesh->blen - len - 1); - mesh->blen -= len + 1; + memcpy(state->line, state->buffer, len); + state->line[len] = 0; + memmove(state->buffer, newline + 1, state->blen - len - 1); + state->blen -= len + 1; return true; } @@ -1546,8 +1558,6 @@ bool meshlink_start(meshlink_handle_t *mesh) { return false; } - mesh->thedatalen = 0; - // TODO: open listening sockets first //Check that a valid name is set @@ -2587,26 +2597,33 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { return false; } + join_state_t state = { + .mesh = mesh, + .sock = -1, + }; + + ecdsa_t *key = NULL; + ecdsa_t *hiskey = NULL; + + //TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL. + char copy[strlen(invitation) + 1]; + pthread_mutex_lock(&mesh->mutex); //Before doing meshlink_join make sure we are not connected to another mesh if(mesh->threadstarted) { logger(mesh, MESHLINK_ERROR, "Cannot join while started\n"); meshlink_errno = MESHLINK_EINVAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } // Refuse to join a mesh if we are already part of one. We are part of one if we know at least one other node. if(mesh->nodes->count > 1) { logger(mesh, MESHLINK_ERROR, "Already part of an existing mesh\n"); meshlink_errno = MESHLINK_EINVAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } - //TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL. - char copy[strlen(invitation) + 1]; strcpy(copy, invitation); // Split the invitation URL into a list of hostname/port tuples, a key hash and a cookie. @@ -2626,22 +2643,20 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { char *address = copy; char *port = NULL; - if(!b64decode(slash, mesh->hash, 18) || !b64decode(slash + 24, mesh->cookie, 18)) { + if(!b64decode(slash, state.hash, 18) || !b64decode(slash + 24, state.cookie, 18)) { goto invalid; } // Generate a throw-away key for the invitation. - ecdsa_t *key = ecdsa_generate(); + key = ecdsa_generate(); if(!key) { meshlink_errno = MESHLINK_EINTERNAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } char *b64key = ecdsa_get_base64_public_key(key); char *comma; - mesh->sock = -1; while(address && *address) { // We allow commas in the address part to support multiple addresses in one invitation URL. @@ -2681,21 +2696,21 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { if(ai) { for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) { - mesh->sock = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns); + state.sock = socket_in_netns(aip->ai_family, aip->ai_socktype, aip->ai_protocol, mesh->netns); - if(mesh->sock == -1) { + if(state.sock == -1) { logger(mesh, MESHLINK_DEBUG, "Could not open socket: %s\n", strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; continue; } - set_timeout(mesh->sock, 5000); + set_timeout(state.sock, 5000); - if(connect(mesh->sock, aip->ai_addr, aip->ai_addrlen)) { + if(connect(state.sock, aip->ai_addr, aip->ai_addrlen)) { logger(mesh, MESHLINK_DEBUG, "Could not connect to %s port %s: %s\n", address, port, strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; - closesocket(mesh->sock); - mesh->sock = -1; + closesocket(state.sock); + state.sock = -1; continue; } } @@ -2705,30 +2720,27 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { meshlink_errno = MESHLINK_ERESOLV; } - if(mesh->sock != -1 || !comma) { + if(state.sock != -1 || !comma) { break; } address = comma; } - if(mesh->sock == -1) { - pthread_mutex_unlock(&mesh->mutex); - return false; + if(state.sock == -1) { + goto exit; } logger(mesh, MESHLINK_DEBUG, "Connected to %s port %s...\n", address, port); // Tell him we have an invitation, and give him our throw-away key. - mesh->blen = 0; + state.blen = 0; - if(!sendline(mesh->sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, PROT_MINOR, mesh->appname)) { + if(!sendline(state.sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, PROT_MINOR, mesh->appname)) { logger(mesh, MESHLINK_DEBUG, "Error sending request to %s port %s: %s\n", address, port, strerror(errno)); - closesocket(mesh->sock); meshlink_errno = MESHLINK_ENETWORK; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } free(b64key); @@ -2736,58 +2748,51 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { char hisname[4096] = ""; int code, hismajor, hisminor = 0; - if(!recvline(mesh, sizeof(mesh)->line) || sscanf(mesh->line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(mesh, sizeof(mesh)->line) || !rstrip(mesh->line) || sscanf(mesh->line, "%d ", &code) != 1 || code != ACK || strlen(mesh->line) < 3) { + if(!recvline(&state) || sscanf(state.line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(&state) || !rstrip(state.line) || sscanf(state.line, "%d ", &code) != 1 || code != ACK || strlen(state.line) < 3) { logger(mesh, MESHLINK_DEBUG, "Cannot read greeting from peer\n"); - closesocket(mesh->sock); meshlink_errno = MESHLINK_ENETWORK; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } // Check if the hash of the key he gave us matches the hash in the URL. - char *fingerprint = mesh->line + 2; + char *fingerprint = state.line + 2; char hishash[64]; if(sha512(fingerprint, strlen(fingerprint), hishash)) { - logger(mesh, MESHLINK_DEBUG, "Could not create hash\n%s\n", mesh->line + 2); + logger(mesh, MESHLINK_DEBUG, "Could not create hash\n%s\n", state.line + 2); meshlink_errno = MESHLINK_EINTERNAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } - if(memcmp(hishash, mesh->hash, 18)) { - logger(mesh, MESHLINK_DEBUG, "Peer has an invalid key!\n%s\n", mesh->line + 2); + if(memcmp(hishash, state.hash, 18)) { + logger(mesh, MESHLINK_DEBUG, "Peer has an invalid key!\n%s\n", state.line + 2); meshlink_errno = MESHLINK_EPEER; - pthread_mutex_unlock(&mesh->mutex); - return false; - + goto exit; } - ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint); + hiskey = ecdsa_set_base64_public_key(fingerprint); if(!hiskey) { meshlink_errno = MESHLINK_EINTERNAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } // Start an SPTPS session - if(!sptps_start(&mesh->sptps, mesh, true, false, key, hiskey, meshlink_invitation_label, sizeof(meshlink_invitation_label), invitation_send, invitation_receive)) { + if(!sptps_start(&state.sptps, &state, true, false, key, hiskey, meshlink_invitation_label, sizeof(meshlink_invitation_label), invitation_send, invitation_receive)) { meshlink_errno = MESHLINK_EINTERNAL; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } // Feed rest of input buffer to SPTPS - if(!sptps_receive_data(&mesh->sptps, mesh->buffer, mesh->blen)) { + if(!sptps_receive_data(&state.sptps, state.buffer, state.blen)) { meshlink_errno = MESHLINK_EPEER; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } - int len; + ssize_t len; + logger(mesh, MESHLINK_DEBUG, "Starting invitation recv loop: %d %zu\n", state.sock, sizeof(state.line)); - while((len = recv(mesh->sock, mesh->line, sizeof(mesh)->line, 0))) { + while((len = recv(state.sock, state.line, sizeof(state.line), 0))) { if(len < 0) { if(errno == EINTR) { continue; @@ -2795,35 +2800,41 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { logger(mesh, MESHLINK_DEBUG, "Error reading data from %s port %s: %s\n", address, port, strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } - if(!sptps_receive_data(&mesh->sptps, mesh->line, len)) { + if(!sptps_receive_data(&state.sptps, state.line, len)) { meshlink_errno = MESHLINK_EPEER; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } } - sptps_stop(&mesh->sptps); - ecdsa_free(hiskey); - ecdsa_free(key); - closesocket(mesh->sock); - - if(!mesh->success) { + if(!state.success) { logger(mesh, MESHLINK_DEBUG, "Connection closed by peer, invitation cancelled.\n"); meshlink_errno = MESHLINK_EPEER; - pthread_mutex_unlock(&mesh->mutex); - return false; + goto exit; } + sptps_stop(&state.sptps); + ecdsa_free(hiskey); + ecdsa_free(key); + closesocket(state.sock); + pthread_mutex_unlock(&mesh->mutex); return true; invalid: logger(mesh, MESHLINK_DEBUG, "Invalid invitation URL\n"); meshlink_errno = MESHLINK_EINVAL; +exit: + sptps_stop(&state.sptps); + ecdsa_free(hiskey); + ecdsa_free(key); + + if(state.sock != -1) { + closesocket(state.sock); + } + pthread_mutex_unlock(&mesh->mutex); return false; } @@ -3906,6 +3917,17 @@ void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class pthread_mutex_unlock(&mesh->mutex); } +extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, bool inviter_commits_first) { + if(!mesh) { + meshlink_errno = EINVAL; + return; + } + + pthread_mutex_lock(&mesh->mutex); + mesh->inviter_commits_first = inviter_commits_first; + pthread_mutex_unlock(&mesh->mutex); +} + void handle_network_change(meshlink_handle_t *mesh, bool online) { (void)online; @@ -3931,7 +3953,6 @@ void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t meshlink_errno) { } } - static void __attribute__((constructor)) meshlink_init(void) { crypto_init(); } diff --git a/src/meshlink_internal.h b/src/meshlink_internal.h index 6aa87171..8104ba60 100644 --- a/src/meshlink_internal.h +++ b/src/meshlink_internal.h @@ -192,17 +192,6 @@ struct meshlink_handle { char *catta_servicetype; unsigned int catta_interfaces; - // State used for meshlink_join() - int sock; - char cookie[18], hash[18]; - bool success; - sptps_t sptps; - char *data; - size_t thedatalen; - size_t blen; - char line[4096]; - char buffer[4096]; - // Proxy configuration, currently not exposed. char *proxyhost; char *proxyport; -- 2.39.5