From d1d09fadfe04b30d5275021524092341cb0c58c8 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Mon, 12 Jul 2021 21:51:55 +0200 Subject: [PATCH] Reduce memory usage of meshlink_join(). Reduce the size of the buffers, and allocate the join state on the heap. --- src/meshlink.c | 95 ++++++++++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 42 deletions(-) diff --git a/src/meshlink.c b/src/meshlink.c index ec8024e..aadbaf3 100644 --- a/src/meshlink.c +++ b/src/meshlink.c @@ -45,6 +45,8 @@ meshlink_log_level_t global_log_level; typedef bool (*search_node_by_condition_t)(const node_t *, const void *); +#define BUFSIZE 128 + static int rstrip(char *value) { int len = strlen(value); @@ -152,7 +154,7 @@ static bool write_main_config_files(meshlink_handle_t *mesh) { return true; } - uint8_t buf[4096]; + uint8_t buf[BUFSIZE]; /* Write the main config file */ packmsg_output_t out = {buf, sizeof buf}; @@ -191,8 +193,8 @@ typedef struct { char *data; size_t thedatalen; size_t blen; - char line[4096]; - char buffer[4096]; + char line[BUFSIZE]; + char buffer[BUFSIZE]; } join_state_t; static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) { @@ -417,7 +419,7 @@ static bool recvline(join_state_t *state) { } static bool sendline(int fd, const char *format, ...) { - char buffer[4096]; + char buffer[BUFSIZE]; char *p = buffer; int blen = 0; va_list ap; @@ -1729,16 +1731,15 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { return false; } - join_state_t state = { - .mesh = mesh, - .sock = -1, - }; + join_state_t *state = xzalloc(sizeof * state); + state->mesh = mesh; + state->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]; + char *copy = xstrdup(invitation); if(pthread_mutex_lock(&mesh->mutex) != 0) { abort(); @@ -1758,8 +1759,6 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { goto exit; } - strcpy(copy, invitation); - // Split the invitation URL into a list of hostname/port tuples, a key hash and a cookie. char *slash = strchr(copy, '/'); @@ -1777,16 +1776,19 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { char *address = copy; char *port = NULL; - if(!b64decode(slash, state.hash, 18) || !b64decode(slash + 24, state.cookie, 18)) { + if(!b64decode(slash, state->hash, 18) || !b64decode(slash + 24, state->cookie, 18)) { goto invalid; } + logger(mesh, MESHLINK_DEBUG, "Done"); + if(mesh->inviter_commits_first) { - memcpy(state.cookie + 18, ecdsa_get_public_key(mesh->private_key), 32); + memcpy(state->cookie + 18, ecdsa_get_public_key(mesh->private_key), 32); } // Generate a throw-away key for the invitation. key = ecdsa_generate(); + logger(mesh, MESHLINK_DEBUG, "Done"); if(!key) { meshlink_errno = MESHLINK_EINTERNAL; @@ -1834,9 +1836,9 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { if(ai) { for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) { - state.sock = socket_in_netns(aip->ai_family, SOCK_STREAM, IPPROTO_TCP, mesh->netns); + state->sock = socket_in_netns(aip->ai_family, SOCK_STREAM, IPPROTO_TCP, mesh->netns); - if(state.sock == -1) { + if(state->sock == -1) { logger(mesh, MESHLINK_DEBUG, "Could not open socket: %s\n", strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; continue; @@ -1844,16 +1846,16 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { #ifdef SO_NOSIGPIPE int nosigpipe = 1; - setsockopt(state.sock, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe)); + setsockopt(state->sock, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe)); #endif - set_timeout(state.sock, 5000); + set_timeout(state->sock, 5000); - if(connect(state.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(state.sock); - state.sock = -1; + closesocket(state->sock); + state->sock = -1; continue; } @@ -1865,14 +1867,14 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { meshlink_errno = MESHLINK_ERESOLV; } - if(state.sock != -1 || !comma) { + if(state->sock != -1 || !comma) { break; } address = comma; } - if(state.sock == -1) { + if(state->sock == -1) { goto exit; } @@ -1880,9 +1882,9 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { // Tell him we have an invitation, and give him our throw-away key. - state.blen = 0; + state->blen = 0; - if(!sendline(state.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_ERROR, "Error sending request to %s port %s: %s\n", address, port, strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; goto exit; @@ -1890,27 +1892,27 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { free(b64key); - char hisname[4096] = ""; + char hisname[BUFSIZE] = ""; int code, hismajor, hisminor = 0; - 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) { + 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_ERROR, "Cannot read greeting from peer\n"); meshlink_errno = MESHLINK_ENETWORK; goto exit; } // Check if the hash of the key he gave us matches the hash in the URL. - char *fingerprint = state.line + 2; + char *fingerprint = state->line + 2; char hishash[64]; if(sha512(fingerprint, strlen(fingerprint), hishash)) { - logger(mesh, MESHLINK_ERROR, "Could not create hash\n%s\n", state.line + 2); + logger(mesh, MESHLINK_ERROR, "Could not create hash\n%s\n", state->line + 2); meshlink_errno = MESHLINK_EINTERNAL; goto exit; } - if(memcmp(hishash, state.hash, 18)) { - logger(mesh, MESHLINK_ERROR, "Peer has an invalid key!\n%s\n", state.line + 2); + if(memcmp(hishash, state->hash, 18)) { + logger(mesh, MESHLINK_ERROR, "Peer has an invalid key!\n%s\n", state->line + 2); meshlink_errno = MESHLINK_EPEER; goto exit; } @@ -1923,47 +1925,55 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) { } // Start an SPTPS session - if(!sptps_start(&state.sptps, &state, 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; goto exit; } // Feed rest of input buffer to SPTPS - if(!sptps_receive_data(&state.sptps, state.buffer, state.blen)) { + if(!sptps_receive_data(&state->sptps, state->buffer, state->blen)) { meshlink_errno = MESHLINK_EPEER; goto exit; } ssize_t len; - logger(mesh, MESHLINK_DEBUG, "Starting invitation recv loop: %d %zu\n", state.sock, sizeof(state.line)); + logger(mesh, MESHLINK_DEBUG, "Starting invitation recv loop: %d %zu\n", state->sock, sizeof(state->line)); - while((len = recv(state.sock, state.line, sizeof(state.line), 0))) { + while((len = recv(state->sock, state->line, sizeof(state->line), 0))) { if(len < 0) { if(errno == EINTR) { continue; } + if(errno == ENOTCONN) { + break; + } + logger(mesh, MESHLINK_ERROR, "Error reading data from %s port %s: %s\n", address, port, strerror(errno)); meshlink_errno = MESHLINK_ENETWORK; goto exit; } - if(!sptps_receive_data(&state.sptps, state.line, len)) { + if(!sptps_receive_data(&state->sptps, state->line, len)) { meshlink_errno = MESHLINK_EPEER; goto exit; } + + if(state->success) { + break; + } } - if(!state.success) { + if(!state->success) { logger(mesh, MESHLINK_ERROR, "Connection closed by peer, invitation cancelled.\n"); meshlink_errno = MESHLINK_EPEER; goto exit; } - sptps_stop(&state.sptps); + sptps_stop(&state->sptps); ecdsa_free(hiskey); ecdsa_free(key); - closesocket(state.sock); + closesocket(state->sock); pthread_mutex_unlock(&mesh->mutex); return true; @@ -1972,15 +1982,16 @@ invalid: logger(mesh, MESHLINK_ERROR, "Invalid invitation URL\n"); meshlink_errno = MESHLINK_EINVAL; exit: - sptps_stop(&state.sptps); + sptps_stop(&state->sptps); ecdsa_free(hiskey); ecdsa_free(key); - if(state.sock != -1) { - closesocket(state.sock); + if(state->sock != -1) { + closesocket(state->sock); } pthread_mutex_unlock(&mesh->mutex); + free(copy); return false; } @@ -1992,7 +2003,7 @@ char *meshlink_export(meshlink_handle_t *mesh) { // Create a config file on the fly. - uint8_t buf[4096]; + uint8_t buf[BUFSIZE]; packmsg_output_t out = {buf, sizeof(buf)}; packmsg_add_uint32(&out, MESHLINK_CONFIG_VERSION); packmsg_add_str(&out, mesh->name); -- 2.39.5