Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 722 insertions, 0 deletions

diff --git a/src/socket-proxy/socket-proxyd.c b/src/socket-proxy/socket-proxyd.c
new file mode 100644
index 0000000..287fd6c
--- /dev/null
+++ b/src/socket-proxy/socket-proxyd.c
@@ -0,0 +1,722 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "sd-daemon.h"
+#include "sd-event.h"
+#include "sd-resolve.h"
+
+#include "alloc-util.h"
+#include "build.h"
+#include "daemon-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "main-func.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "pretty-print.h"
+#include "resolve-private.h"
+#include "set.h"
+#include "socket-util.h"
+#include "string-util.h"
+
+#define BUFFER_SIZE (256 * 1024)
+
+static unsigned arg_connections_max = 256;
+static const char *arg_remote_host = NULL;
+static usec_t arg_exit_idle_time = USEC_INFINITY;
+
+typedef struct Context {
+        sd_event *event;
+        sd_resolve *resolve;
+        sd_event_source *idle_time;
+
+        Set *listen;
+        Set *connections;
+} Context;
+
+typedef struct Connection {
+        Context *context;
+
+        int server_fd, client_fd;
+        int server_to_client_buffer[2]; /* a pipe */
+        int client_to_server_buffer[2]; /* a pipe */
+
+        size_t server_to_client_buffer_full, client_to_server_buffer_full;
+        size_t server_to_client_buffer_size, client_to_server_buffer_size;
+
+        sd_event_source *server_event_source, *client_event_source;
+
+        sd_resolve_query *resolve_query;
+} Connection;
+
+static void connection_free(Connection *c) {
+        assert(c);
+
+        if (c->context)
+                set_remove(c->context->connections, c);
+
+        sd_event_source_unref(c->server_event_source);
+        sd_event_source_unref(c->client_event_source);
+
+        safe_close(c->server_fd);
+        safe_close(c->client_fd);
+
+        safe_close_pair(c->server_to_client_buffer);
+        safe_close_pair(c->client_to_server_buffer);
+
+        sd_resolve_query_unref(c->resolve_query);
+
+        free(c);
+}
+
+static int idle_time_cb(sd_event_source *s, uint64_t usec, void *userdata) {
+        Context *c = userdata;
+        int r;
+
+        if (!set_isempty(c->connections)) {
+                log_warning("Idle timer fired even though there are connections, ignoring");
+                return 0;
+        }
+
+        r = sd_event_exit(c->event, 0);
+        if (r < 0) {
+                log_warning_errno(r, "Error while stopping event loop, ignoring: %m");
+                return 0;
+        }
+        return 0;
+}
+
+static int connection_release(Connection *c) {
+        Context *context = ASSERT_PTR(ASSERT_PTR(c)->context);
+        int r;
+
+        connection_free(c);
+
+        if (arg_exit_idle_time < USEC_INFINITY && set_isempty(context->connections)) {
+                if (context->idle_time) {
+                        r = sd_event_source_set_time_relative(context->idle_time, arg_exit_idle_time);
+                        if (r < 0)
+                                return log_error_errno(r, "Error while setting idle time: %m");
+
+                        r = sd_event_source_set_enabled(context->idle_time, SD_EVENT_ONESHOT);
+                        if (r < 0)
+                                return log_error_errno(r, "Error while enabling idle time: %m");
+                } else {
+                        r = sd_event_add_time_relative(
+                                        context->event, &context->idle_time, CLOCK_MONOTONIC,
+                                        arg_exit_idle_time, 0, idle_time_cb, context);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create idle timer: %m");
+                }
+        }
+
+        return 0;
+}
+
+static void context_clear(Context *context) {
+        assert(context);
+
+        set_free_with_destructor(context->listen, sd_event_source_unref);
+        set_free_with_destructor(context->connections, connection_free);
+
+        sd_event_unref(context->event);
+        sd_resolve_unref(context->resolve);
+        sd_event_source_unref(context->idle_time);
+}
+
+static int connection_create_pipes(Connection *c, int buffer[static 2], size_t *sz) {
+        int r;
+
+        assert(c);
+        assert(buffer);
+        assert(sz);
+
+        if (buffer[0] >= 0)
+                return 0;
+
+        r = pipe2(buffer, O_CLOEXEC|O_NONBLOCK);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to allocate pipe buffer: %m");
+
+        (void) fcntl(buffer[0], F_SETPIPE_SZ, BUFFER_SIZE);
+
+        r = fcntl(buffer[0], F_GETPIPE_SZ);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to get pipe buffer size: %m");
+
+        assert(r > 0);
+        *sz = r;
+
+        return 0;
+}
+
+static int connection_shovel(
+                Connection *c,
+                int *from, int buffer[2], int *to,
+                size_t *full, size_t *sz,
+                sd_event_source **from_source, sd_event_source **to_source) {
+
+        bool shoveled;
+
+        assert(c);
+        assert(from);
+        assert(buffer);
+        assert(buffer[0] >= 0);
+        assert(buffer[1] >= 0);
+        assert(to);
+        assert(full);
+        assert(sz);
+        assert(from_source);
+        assert(to_source);
+
+        do {
+                ssize_t z;
+
+                shoveled = false;
+
+                if (*full < *sz && *from >= 0 && *to >= 0) {
+                        z = splice(*from, NULL, buffer[1], NULL, *sz - *full, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
+                        if (z > 0) {
+                                *full += z;
+                                shoveled = true;
+                        } else if (z == 0 || ERRNO_IS_DISCONNECT(errno)) {
+                                *from_source = sd_event_source_unref(*from_source);
+                                *from = safe_close(*from);
+                        } else if (!ERRNO_IS_TRANSIENT(errno))
+                                return log_error_errno(errno, "Failed to splice: %m");
+                }
+
+                if (*full > 0 && *to >= 0) {
+                        z = splice(buffer[0], NULL, *to, NULL, *full, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
+                        if (z > 0) {
+                                *full -= z;
+                                shoveled = true;
+                        } else if (z == 0 || ERRNO_IS_DISCONNECT(errno)) {
+                                *to_source = sd_event_source_unref(*to_source);
+                                *to = safe_close(*to);
+                        } else if (!ERRNO_IS_TRANSIENT(errno))
+                                return log_error_errno(errno, "Failed to splice: %m");
+                }
+        } while (shoveled);
+
+        return 0;
+}
+
+static int connection_enable_event_sources(Connection *c);
+
+static int traffic_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Connection *c = ASSERT_PTR(userdata);
+        int r;
+
+        assert(s);
+        assert(fd >= 0);
+
+        r = connection_shovel(c,
+                              &c->server_fd, c->server_to_client_buffer, &c->client_fd,
+                              &c->server_to_client_buffer_full, &c->server_to_client_buffer_size,
+                              &c->server_event_source, &c->client_event_source);
+        if (r < 0)
+                goto quit;
+
+        r = connection_shovel(c,
+                              &c->client_fd, c->client_to_server_buffer, &c->server_fd,
+                              &c->client_to_server_buffer_full, &c->client_to_server_buffer_size,
+                              &c->client_event_source, &c->server_event_source);
+        if (r < 0)
+                goto quit;
+
+        /* EOF on both sides? */
+        if (c->server_fd < 0 && c->client_fd < 0)
+                goto quit;
+
+        /* Server closed, and all data written to client? */
+        if (c->server_fd < 0 && c->server_to_client_buffer_full <= 0)
+                goto quit;
+
+        /* Client closed, and all data written to server? */
+        if (c->client_fd < 0 && c->client_to_server_buffer_full <= 0)
+                goto quit;
+
+        r = connection_enable_event_sources(c);
+        if (r < 0)
+                goto quit;
+
+        return 1;
+
+quit:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int connection_enable_event_sources(Connection *c) {
+        uint32_t a = 0, b = 0;
+        int r;
+
+        assert(c);
+
+        if (c->server_to_client_buffer_full > 0)
+                b |= EPOLLOUT;
+        if (c->server_to_client_buffer_full < c->server_to_client_buffer_size)
+                a |= EPOLLIN;
+
+        if (c->client_to_server_buffer_full > 0)
+                a |= EPOLLOUT;
+        if (c->client_to_server_buffer_full < c->client_to_server_buffer_size)
+                b |= EPOLLIN;
+
+        if (c->server_event_source)
+                r = sd_event_source_set_io_events(c->server_event_source, a);
+        else if (c->server_fd >= 0)
+                r = sd_event_add_io(c->context->event, &c->server_event_source, c->server_fd, a, traffic_cb, c);
+        else
+                r = 0;
+
+        if (r < 0)
+                return log_error_errno(r, "Failed to set up server event source: %m");
+
+        if (c->client_event_source)
+                r = sd_event_source_set_io_events(c->client_event_source, b);
+        else if (c->client_fd >= 0)
+                r = sd_event_add_io(c->context->event, &c->client_event_source, c->client_fd, b, traffic_cb, c);
+        else
+                r = 0;
+
+        if (r < 0)
+                return log_error_errno(r, "Failed to set up client event source: %m");
+
+        return 0;
+}
+
+static int connection_complete(Connection *c) {
+        int r;
+
+        assert(c);
+
+        r = connection_create_pipes(c, c->server_to_client_buffer, &c->server_to_client_buffer_size);
+        if (r < 0)
+                goto fail;
+
+        r = connection_create_pipes(c, c->client_to_server_buffer, &c->client_to_server_buffer_size);
+        if (r < 0)
+                goto fail;
+
+        r = connection_enable_event_sources(c);
+        if (r < 0)
+                goto fail;
+
+        return 0;
+
+fail:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int connect_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Connection *c = ASSERT_PTR(userdata);
+        socklen_t solen;
+        int error, r;
+
+        assert(s);
+        assert(fd >= 0);
+
+        solen = sizeof(error);
+        r = getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &solen);
+        if (r < 0) {
+                log_error_errno(errno, "Failed to issue SO_ERROR: %m");
+                goto fail;
+        }
+
+        if (error != 0) {
+                log_error_errno(error, "Failed to connect to remote host: %m");
+                goto fail;
+        }
+
+        c->client_event_source = sd_event_source_unref(c->client_event_source);
+
+        return connection_complete(c);
+
+fail:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int connection_start(Connection *c, struct sockaddr *sa, socklen_t salen) {
+        int r;
+
+        assert(c);
+        assert(sa);
+        assert(salen);
+
+        c->client_fd = socket(sa->sa_family, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+        if (c->client_fd < 0) {
+                log_error_errno(errno, "Failed to get remote socket: %m");
+                goto fail;
+        }
+
+        r = connect(c->client_fd, sa, salen);
+        if (r < 0) {
+                if (errno == EINPROGRESS) {
+                        r = sd_event_add_io(c->context->event, &c->client_event_source, c->client_fd, EPOLLOUT, connect_cb, c);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to add connection socket: %m");
+                                goto fail;
+                        }
+
+                        r = sd_event_source_set_enabled(c->client_event_source, SD_EVENT_ONESHOT);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to enable oneshot event source: %m");
+                                goto fail;
+                        }
+                } else {
+                        log_error_errno(errno, "Failed to connect to remote host: %m");
+                        goto fail;
+                }
+        } else {
+                r = connection_complete(c);
+                if (r < 0)
+                        goto fail;
+        }
+
+        return 0;
+
+fail:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, Connection *c) {
+        assert(q);
+        assert(c);
+
+        if (ret != 0) {
+                log_error("Failed to resolve host: %s", gai_strerror(ret));
+                goto fail;
+        }
+
+        c->resolve_query = sd_resolve_query_unref(c->resolve_query);
+
+        return connection_start(c, ai->ai_addr, ai->ai_addrlen);
+
+fail:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int resolve_remote(Connection *c) {
+
+        static const struct addrinfo hints = {
+                .ai_family = AF_UNSPEC,
+                .ai_socktype = SOCK_STREAM,
+        };
+
+        const char *node, *service;
+        int r;
+
+        if (IN_SET(arg_remote_host[0], '/', '@')) {
+                union sockaddr_union sa;
+                int sa_len;
+
+                r = sockaddr_un_set_path(&sa.un, arg_remote_host);
+                if (r < 0) {
+                        log_error_errno(r, "Specified address doesn't fit in an AF_UNIX address, refusing: %m");
+                        goto fail;
+                }
+                sa_len = r;
+
+                return connection_start(c, &sa.sa, sa_len);
+        }
+
+        service = strrchr(arg_remote_host, ':');
+        if (service) {
+                node = strndupa_safe(arg_remote_host,
+                                     service - arg_remote_host);
+                service++;
+        } else {
+                node = arg_remote_host;
+                service = "80";
+        }
+
+        log_debug("Looking up address info for %s:%s", node, service);
+        r = resolve_getaddrinfo(c->context->resolve, &c->resolve_query, node, service, &hints, resolve_handler, NULL, c);
+        if (r < 0) {
+                log_error_errno(r, "Failed to resolve remote host: %m");
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        connection_release(c);
+        return 0; /* ignore errors, continue serving */
+}
+
+static int add_connection_socket(Context *context, int fd) {
+        Connection *c;
+        int r;
+
+        assert(context);
+        assert(fd >= 0);
+
+        if (set_size(context->connections) > arg_connections_max) {
+                log_warning("Hit connection limit, refusing connection.");
+                safe_close(fd);
+                return 0;
+        }
+
+        if (context->idle_time) {
+                r = sd_event_source_set_enabled(context->idle_time, SD_EVENT_OFF);
+                if (r < 0)
+                        log_warning_errno(r, "Unable to disable idle timer, continuing: %m");
+        }
+
+        c = new(Connection, 1);
+        if (!c) {
+                log_oom();
+                return 0;
+        }
+
+        *c = (Connection) {
+               .context = context,
+               .server_fd = fd,
+               .client_fd = -EBADF,
+               .server_to_client_buffer = EBADF_PAIR,
+               .client_to_server_buffer = EBADF_PAIR,
+        };
+
+        r = set_ensure_put(&context->connections, NULL, c);
+        if (r < 0) {
+                free(c);
+                log_oom();
+                return 0;
+        }
+
+        return resolve_remote(c);
+}
+
+static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_free_ char *peer = NULL;
+        Context *context = ASSERT_PTR(userdata);
+        int nfd = -EBADF, r;
+
+        assert(s);
+        assert(fd >= 0);
+        assert(revents & EPOLLIN);
+
+        nfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+        if (nfd < 0) {
+                if (!ERRNO_IS_ACCEPT_AGAIN(errno))
+                        log_warning_errno(errno, "Failed to accept() socket: %m");
+        } else {
+                (void) getpeername_pretty(nfd, true, &peer);
+                log_debug("New connection from %s", strna(peer));
+
+                r = add_connection_socket(context, nfd);
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to accept connection, ignoring: %m");
+                        safe_close(nfd);
+                }
+        }
+
+        r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
+        if (r < 0)
+                return log_error_errno(r, "Error while re-enabling listener with ONESHOT: %m");
+
+        return 1;
+}
+
+static int add_listen_socket(Context *context, int fd) {
+        sd_event_source *source;
+        int r;
+
+        assert(context);
+        assert(fd >= 0);
+
+        r = sd_is_socket(fd, 0, SOCK_STREAM, 1);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine socket type: %m");
+        if (r == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Passed in socket is not a stream socket.");
+
+        r = fd_nonblock(fd, true);
+        if (r < 0)
+                return log_error_errno(r, "Failed to mark file descriptor non-blocking: %m");
+
+        r = sd_event_add_io(context->event, &source, fd, EPOLLIN, accept_cb, context);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add event source: %m");
+
+        r = set_ensure_put(&context->listen, NULL, source);
+        if (r < 0) {
+                sd_event_source_unref(source);
+                return log_error_errno(r, "Failed to add source to set: %m");
+        }
+
+        r = sd_event_source_set_exit_on_failure(source, true);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enable exit-on-failure logic: %m");
+
+        /* Set the watcher to oneshot in case other processes are also
+         * watching to accept(). */
+        r = sd_event_source_set_enabled(source, SD_EVENT_ONESHOT);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enable oneshot mode: %m");
+
+        return 0;
+}
+
+static int help(void) {
+        _cleanup_free_ char *link = NULL;
+        _cleanup_free_ char *time_link = NULL;
+        int r;
+
+        r = terminal_urlify_man("systemd-socket-proxyd", "8", &link);
+        if (r < 0)
+                return log_oom();
+        r = terminal_urlify_man("systemd.time", "7", &time_link);
+        if (r < 0)
+                return log_oom();
+
+        printf("%1$s [HOST:PORT]\n"
+               "%1$s [SOCKET]\n\n"
+               "Bidirectionally proxy local sockets to another (possibly remote) socket.\n\n"
+               "  -c --connections-max=  Set the maximum number of connections to be accepted\n"
+               "     --exit-idle-time=   Exit when without a connection for this duration. See\n"
+               "                         the %3$s for time span format\n"
+               "  -h --help              Show this help\n"
+               "     --version           Show package version\n"
+               "\nSee the %2$s for details.\n",
+               program_invocation_short_name,
+               link,
+               time_link);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_EXIT_IDLE,
+                ARG_IGNORE_ENV
+        };
+
+        static const struct option options[] = {
+                { "connections-max", required_argument, NULL, 'c'           },
+                { "exit-idle-time",  required_argument, NULL, ARG_EXIT_IDLE },
+                { "help",            no_argument,       NULL, 'h'           },
+                { "version",         no_argument,       NULL, ARG_VERSION   },
+                {}
+        };
+
+        int c, r;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "c:h", options, NULL)) >= 0)
+
+                switch (c) {
+
+                case 'h':
+                        return help();
+
+                case ARG_VERSION:
+                        return version();
+
+                case 'c':
+                        r = safe_atou(optarg, &arg_connections_max);
+                        if (r < 0) {
+                                log_error("Failed to parse --connections-max= argument: %s", optarg);
+                                return r;
+                        }
+
+                        if (arg_connections_max < 1)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Connection limit is too low.");
+
+                        break;
+
+                case ARG_EXIT_IDLE:
+                        r = parse_sec(optarg, &arg_exit_idle_time);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --exit-idle-time= argument: %s", optarg);
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached();
+                }
+
+        if (optind >= argc)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Not enough parameters.");
+
+        if (argc != optind+1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Too many parameters.");
+
+        arg_remote_host = argv[optind];
+        return 1;
+}
+
+static int run(int argc, char *argv[]) {
+        _cleanup_(context_clear) Context context = {};
+        _unused_ _cleanup_(notify_on_cleanup) const char *notify_stop = NULL;
+        int r, n, fd;
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r;
+
+        r = sd_event_default(&context.event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate event loop: %m");
+
+        r = sd_resolve_default(&context.resolve);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate resolver: %m");
+
+        r = sd_resolve_attach_event(context.resolve, context.event, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to attach resolver: %m");
+
+        sd_event_set_watchdog(context.event, true);
+
+        r = sd_listen_fds(1);
+        if (r < 0)
+                return log_error_errno(r, "Failed to receive sockets from parent.");
+        if (r == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Didn't get any sockets passed in.");
+
+        n = r;
+
+        for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) {
+                r = add_listen_socket(&context, fd);
+                if (r < 0)
+                        return r;
+        }
+
+        notify_stop = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
+        r = sd_event_loop(context.event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to run event loop: %m");
+
+        return 0;
+}
+
+DEFINE_MAIN_FUNCTION(run);