diff options
Diffstat (limited to 'src/saproxy/saproxy.c')
-rw-r--r-- | src/saproxy/saproxy.c | 597 |
1 files changed, 0 insertions, 597 deletions
diff --git a/src/saproxy/saproxy.c b/src/saproxy/saproxy.c deleted file mode 100644 index 6504d09251..0000000000 --- a/src/saproxy/saproxy.c +++ /dev/null @@ -1,597 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2013 David Strauss - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. - ***/ - -#include <arpa/inet.h> -#include <errno.h> -#include <getopt.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <netdb.h> -#include <sys/fcntl.h> -#include <sys/socket.h> -#include <sys/un.h> -#include <unistd.h> - -#include "log.h" -#include "sd-daemon.h" -#include "sd-event.h" -#include "socket-util.h" -#include "util.h" - -#define BUFFER_SIZE 16384 -#define _cleanup_freeaddrinfo_ _cleanup_(freeaddrinfop) - -unsigned int total_clients = 0; - -DEFINE_TRIVIAL_CLEANUP_FUNC(struct addrinfo *, freeaddrinfo); - -struct proxy { - int listen_fd; - bool ignore_env; - bool remote_is_inet; - const char *remote_host; - const char *remote_service; -}; - -struct connection { - int fd; - uint32_t events; - sd_event_source *w; - struct connection *c_destination; - size_t buffer_filled_len; - size_t buffer_sent_len; - char buffer[BUFFER_SIZE]; -}; - -static void free_connection(struct connection *c) { - log_debug("Freeing fd=%d (conn %p).", c->fd, c); - sd_event_source_unref(c->w); - close(c->fd); - free(c); -} - -static int add_event_to_connection(struct connection *c, uint32_t events) { - int r; - - log_debug("Have revents=%d. Adding revents=%d.", c->events, events); - - c->events |= events; - - r = sd_event_source_set_io_events(c->w, c->events); - if (r < 0) { - log_error("Error %d setting revents: %s", r, strerror(-r)); - return r; - } - - r = sd_event_source_set_enabled(c->w, SD_EVENT_ON); - if (r < 0) { - log_error("Error %d enabling source: %s", r, strerror(-r)); - return r; - } - - return 0; -} - -static int remove_event_from_connection(struct connection *c, uint32_t events) { - int r; - - log_debug("Have revents=%d. Removing revents=%d.", c->events, events); - - c->events &= ~events; - - r = sd_event_source_set_io_events(c->w, c->events); - if (r < 0) { - log_error("Error %d setting revents: %s", r, strerror(-r)); - return r; - } - - if (c->events == 0) { - r = sd_event_source_set_enabled(c->w, SD_EVENT_OFF); - if (r < 0) { - log_error("Error %d disabling source: %s", r, strerror(-r)); - return r; - } - } - - return 0; -} - -static int send_buffer(struct connection *sender) { - struct connection *receiver = sender->c_destination; - ssize_t len; - int r = 0; - - /* We cannot assume that even a partial send() indicates that - * the next send() will block. Loop until it does. */ - while (sender->buffer_filled_len > sender->buffer_sent_len) { - len = send(receiver->fd, sender->buffer + sender->buffer_sent_len, sender->buffer_filled_len - sender->buffer_sent_len, 0); - log_debug("send(%d, ...)=%ld", receiver->fd, len); - if (len < 0) { - if (errno != EWOULDBLOCK && errno != EAGAIN) { - log_error("Error %d in send to fd=%d: %m", errno, receiver->fd); - return -errno; - } - else { - /* send() is in a blocking state. */ - break; - } - } - - /* len < 0 can't occur here. len == 0 is possible but - * undefined behavior for nonblocking send(). */ - assert(len > 0); - sender->buffer_sent_len += len; - } - - log_debug("send(%d, ...) completed with %lu bytes still buffered.", receiver->fd, sender->buffer_filled_len - sender->buffer_sent_len); - - /* Detect a would-block state or partial send. */ - if (sender->buffer_filled_len > sender->buffer_sent_len) { - - /* If the buffer is full, disable events coming for recv. */ - if (sender->buffer_filled_len == BUFFER_SIZE) { - r = remove_event_from_connection(sender, EPOLLIN); - if (r < 0) { - log_error("Error %d disabling EPOLLIN for fd=%d: %s", r, sender->fd, strerror(-r)); - return r; - } - } - - /* Watch for when the recipient can be sent data again. */ - r = add_event_to_connection(receiver, EPOLLOUT); - if (r < 0) { - log_error("Error %d enabling EPOLLOUT for fd=%d: %s", r, receiver->fd, strerror(-r)); - return r; - } - log_debug("Done with recv for fd=%d. Waiting on send for fd=%d.", sender->fd, receiver->fd); - return r; - } - - /* If we sent everything without blocking, the buffer is now empty. */ - sender->buffer_filled_len = 0; - sender->buffer_sent_len = 0; - - /* Enable the sender's receive watcher, in case the buffer was - * full and we disabled it. */ - r = add_event_to_connection(sender, EPOLLIN); - if (r < 0) { - log_error("Error %d enabling EPOLLIN for fd=%d: %s", r, sender->fd, strerror(-r)); - return r; - } - - /* Disable the other side's send watcher, as we have no data to send now. */ - r = remove_event_from_connection(receiver, EPOLLOUT); - if (r < 0) { - log_error("Error %d disabling EPOLLOUT for fd=%d: %s", r, receiver->fd, strerror(-r)); - return r; - } - - return 0; -} - -static int transfer_data_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - struct connection *c = (struct connection *) userdata; - int r = 0; - ssize_t len; - - assert(revents & (EPOLLIN | EPOLLOUT)); - assert(fd == c->fd); - assert(s == c->w); - - log_debug("Got event revents=%d from fd=%d (conn %p).", revents, fd, c); - - if (revents & EPOLLIN) { - log_debug("About to recv up to %lu bytes from fd=%d (%lu/BUFFER_SIZE).", BUFFER_SIZE - c->buffer_filled_len, fd, c->buffer_filled_len); - - /* Receive until the buffer's full, there's no more data, - * or the client/server disconnects. */ - while (c->buffer_filled_len < BUFFER_SIZE) { - len = recv(fd, c->buffer + c->buffer_filled_len, BUFFER_SIZE - c->buffer_filled_len, 0); - log_debug("recv(%d, ...)=%ld", fd, len); - if (len < 0) { - if (errno != EWOULDBLOCK && errno != EAGAIN) { - log_error("Error %d in recv from fd=%d: %m", errno, fd); - return -errno; - } - else { - /* recv() is in a blocking state. */ - break; - } - } - else if (len == 0) { - log_debug("Clean disconnection from fd=%d", fd); - total_clients--; - free_connection(c->c_destination); - free_connection(c); - return 0; - } - - assert(len > 0); - log_debug("Recording that the buffer got %ld more bytes full.", len); - c->buffer_filled_len += len; - log_debug("Buffer now has %ld bytes full.", c->buffer_filled_len); - } - - /* Try sending the data immediately. */ - return send_buffer(c); - } - else { - return send_buffer(c->c_destination); - } - - return r; -} - -/* Once sending to the server is unblocked, set up the real watchers. */ -static int connected_to_server_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - struct sd_event *e = NULL; - struct connection *c_server_to_client = (struct connection *) userdata; - struct connection *c_client_to_server = c_server_to_client->c_destination; - int r; - - assert(revents & EPOLLOUT); - - e = sd_event_get(s); - - /* Cancel the initial write watcher for the server. */ - sd_event_source_unref(s); - - log_debug("Connected to server. Initializing watchers for receiving data."); - - /* A recv watcher for the server. */ - r = sd_event_add_io(e, c_server_to_client->fd, EPOLLIN, transfer_data_cb, c_server_to_client, &c_server_to_client->w); - if (r < 0) { - log_error("Error %d creating recv watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r)); - goto fail; - } - c_server_to_client->events = EPOLLIN; - - /* A recv watcher for the client. */ - r = sd_event_add_io(e, c_client_to_server->fd, EPOLLIN, transfer_data_cb, c_client_to_server, &c_client_to_server->w); - if (r < 0) { - log_error("Error %d creating recv watcher for fd=%d: %s", r, c_client_to_server->fd, strerror(-r)); - goto fail; - } - c_client_to_server->events = EPOLLIN; - -goto finish; - -fail: - free_connection(c_client_to_server); - free_connection(c_server_to_client); - -finish: - return r; -} - -static int get_server_connection_fd(const struct proxy *proxy) { - int server_fd; - int r = -EBADF; - int len; - - if (proxy->remote_is_inet) { - int s; - _cleanup_freeaddrinfo_ struct addrinfo *result = NULL; - struct addrinfo hints = {.ai_family = AF_UNSPEC, - .ai_socktype = SOCK_STREAM, - .ai_flags = AI_PASSIVE}; - - log_debug("Looking up address info for %s:%s", proxy->remote_host, proxy->remote_service); - s = getaddrinfo(proxy->remote_host, proxy->remote_service, &hints, &result); - if (s != 0) { - log_error("getaddrinfo error (%d): %s", s, gai_strerror(s)); - return r; - } - - if (result == NULL) { - log_error("getaddrinfo: no result"); - return r; - } - - /* @TODO: Try connecting to all results instead of just the first. */ - server_fd = socket(result->ai_family, result->ai_socktype | SOCK_NONBLOCK, result->ai_protocol); - if (server_fd < 0) { - log_error("Error %d creating socket: %m", errno); - return r; - } - - r = connect(server_fd, result->ai_addr, result->ai_addrlen); - /* Ignore EINPROGRESS errors because they're expected for a nonblocking socket. */ - if (r < 0 && errno != EINPROGRESS) { - log_error("Error %d while connecting to socket %s:%s: %m", errno, proxy->remote_host, proxy->remote_service); - return r; - } - } - else { - struct sockaddr_un remote; - - server_fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0); - if (server_fd < 0) { - log_error("Error %d creating socket: %m", errno); - return -EBADFD; - } - - remote.sun_family = AF_UNIX; - strncpy(remote.sun_path, proxy->remote_host, sizeof(remote.sun_path)); - len = strlen(remote.sun_path) + sizeof(remote.sun_family); - r = connect(server_fd, (struct sockaddr *) &remote, len); - if (r < 0 && errno != EINPROGRESS) { - log_error("Error %d while connecting to Unix domain socket %s: %m", errno, proxy->remote_host); - return -EBADFD; - } - } - - log_debug("Server connection is fd=%d", server_fd); - return server_fd; -} - -static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - struct proxy *proxy = (struct proxy *) userdata; - struct connection *c_server_to_client; - struct connection *c_client_to_server; - int r = 0; - union sockaddr_union sa; - socklen_t salen = sizeof(sa); - - assert(revents & EPOLLIN); - - c_server_to_client = malloc0(sizeof(struct connection)); - if (c_server_to_client == NULL) { - log_oom(); - goto fail; - } - - c_client_to_server = malloc0(sizeof(struct connection)); - if (c_client_to_server == NULL) { - log_oom(); - goto fail; - } - - c_server_to_client->fd = get_server_connection_fd(proxy); - if (c_server_to_client->fd < 0) { - log_error("Error initiating server connection."); - goto fail; - } - - c_client_to_server->fd = accept(fd, (struct sockaddr *) &sa, &salen); - if (c_client_to_server->fd < 0) { - log_error("Error accepting client connection."); - goto fail; - } - - /* Unlike on BSD, client sockets do not inherit nonblocking status - * from the listening socket. */ - r = fd_nonblock(c_client_to_server->fd, true); - if (r < 0) { - log_error("Error %d marking client connection as nonblocking: %s", r, strerror(-r)); - goto fail; - } - - if (sa.sa.sa_family == AF_INET || sa.sa.sa_family == AF_INET6) { - char sa_str[INET6_ADDRSTRLEN]; - const char *success; - - success = inet_ntop(sa.sa.sa_family, &sa.in6.sin6_addr, sa_str, INET6_ADDRSTRLEN); - if (success == NULL) - log_warning("Error %d calling inet_ntop: %m", errno); - else - log_debug("Accepted client connection from %s as fd=%d", sa_str, c_client_to_server->fd); - } - else { - log_debug("Accepted client connection (non-IP) as fd=%d", c_client_to_server->fd); - } - - total_clients++; - log_debug("Client fd=%d (conn %p) successfully connected. Total clients: %u", c_client_to_server->fd, c_client_to_server, total_clients); - log_debug("Server fd=%d (conn %p) successfully initialized.", c_server_to_client->fd, c_server_to_client); - - /* Initialize watcher for send to server; this shows connectivity. */ - r = sd_event_add_io(sd_event_get(s), c_server_to_client->fd, EPOLLOUT, connected_to_server_cb, c_server_to_client, &c_server_to_client->w); - if (r < 0) { - log_error("Error %d creating connectivity watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r)); - goto fail; - } - - /* Allow lookups of the opposite connection. */ - c_server_to_client->c_destination = c_client_to_server; - c_client_to_server->c_destination = c_server_to_client; - - goto finish; - -fail: - log_warning("Accepting a client connection or connecting to the server failed."); - free_connection(c_client_to_server); - free_connection(c_server_to_client); - -finish: - /* Preserve the main loop even if a single proxy setup fails. */ - return 0; -} - -static int run_main_loop(struct proxy *proxy) { - int r = EXIT_SUCCESS; - struct sd_event *e = NULL; - sd_event_source *w_accept = NULL; - - r = sd_event_new(&e); - if (r < 0) - goto finish; - - r = fd_nonblock(proxy->listen_fd, true); - if (r < 0) - goto finish; - - log_debug("Initializing main listener fd=%d", proxy->listen_fd); - - sd_event_add_io(e, proxy->listen_fd, EPOLLIN, accept_cb, proxy, &w_accept); - - log_debug("Initialized main listener. Entering loop."); - - sd_event_loop(e); - -finish: - sd_event_source_unref(w_accept); - sd_event_unref(e); - - return r; -} - -static int help(void) { - - printf("%s hostname-or-ip port-or-service\n" - "%s unix-domain-socket-path\n\n" - "Inherit a socket. Bidirectionally proxy.\n\n" - " -h --help Show this help\n" - " --version Print version and exit\n" - " --ignore-env Ignore expected systemd environment\n", - program_invocation_short_name, - program_invocation_short_name); - - return 0; -} - -static void version(void) { - puts(PACKAGE_STRING " saproxy"); -} - -static int parse_argv(int argc, char *argv[], struct proxy *p) { - - enum { - ARG_VERSION = 0x100, - ARG_IGNORE_ENV - }; - - static const struct option options[] = { - { "help", no_argument, NULL, 'h' }, - { "version", no_argument, NULL, ARG_VERSION }, - { "ignore-env", no_argument, NULL, ARG_IGNORE_ENV}, - { NULL, 0, NULL, 0 } - }; - - int c; - - assert(argc >= 0); - assert(argv); - - while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { - - switch (c) { - - case 'h': - help(); - return 0; - - case '?': - return -EINVAL; - - case ARG_VERSION: - version(); - return 0; - - case ARG_IGNORE_ENV: - p->ignore_env = true; - continue; - - default: - log_error("Unknown option code %c", c); - return -EINVAL; - } - } - - if (optind + 1 != argc && optind + 2 != argc) { - log_error("Incorrect number of positional arguments."); - help(); - return -EINVAL; - } - - p->remote_host = argv[optind]; - assert(p->remote_host); - - p->remote_is_inet = p->remote_host[0] != '/'; - - if (optind == argc - 2) { - if (!p->remote_is_inet) { - log_error("A port or service is not allowed for Unix socket destinations."); - help(); - return -EINVAL; - } - p->remote_service = argv[optind + 1]; - assert(p->remote_service); - } else if (p->remote_is_inet) { - log_error("A port or service is required for IP destinations."); - help(); - return -EINVAL; - } - - return 1; -} - -int main(int argc, char *argv[]) { - struct proxy p = {}; - int r; - - log_parse_environment(); - log_open(); - - r = parse_argv(argc, argv, &p); - if (r <= 0) - goto finish; - - p.listen_fd = SD_LISTEN_FDS_START; - - if (!p.ignore_env) { - int n; - n = sd_listen_fds(1); - if (n == 0) { - log_error("Found zero inheritable sockets. Are you sure this is running as a socket-activated service?"); - r = EXIT_FAILURE; - goto finish; - } else if (n < 0) { - log_error("Error %d while finding inheritable sockets: %s", n, strerror(-n)); - r = EXIT_FAILURE; - goto finish; - } else if (n > 1) { - log_error("Can't listen on more than one socket."); - r = EXIT_FAILURE; - goto finish; - } - } - - /* @TODO: Check if this proxy can work with datagram sockets. */ - r = sd_is_socket(p.listen_fd, 0, SOCK_STREAM, 1); - if (r < 0) { - log_error("Error %d while checking inherited socket: %s", r, strerror(-r)); - goto finish; - } - - log_info("Starting the socket activation proxy with listener fd=%d.", p.listen_fd); - - r = run_main_loop(&p); - if (r < 0) { - log_error("Error %d from main loop.", r); - goto finish; - } - -finish: - log_close(); - return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; -} |