sd-bus: if we receive an invalid dbus message, ignore and proceeed

[thirdparty/systemd.git] / src / libsystemd / sd-bus / bus-socket.c

diff --git a/src/libsystemd/sd-bus/bus-socket.c b/src/libsystemd/sd-bus/bus-socket.c
index 166fba1579f1bb3453022be1b2ca95bb45d229e5..441b4a816f3af989459fc4024378fd0b413c2736 100644 (file)
--- a/src/libsystemd/sd-bus/bus-socket.c
+++ b/src/libsystemd/sd-bus/bus-socket.c
@@ -1,22 +1,4 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
-/***
-  This file is part of systemd.
-
-  Copyright 2013 Lennart Poettering
-
-  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 <endian.h>
 #include <poll.h>
@@ -39,6 +21,7 @@
 #include "missing.h"
 #include "path-util.h"
 #include "process-util.h"
+#include "rlimit-util.h"
 #include "selinux-util.h"
 #include "signal-util.h"
 #include "stdio-util.h"
@@ -62,8 +45,7 @@ static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) {
 
                 size -= i->iov_len;
 
-                i->iov_base = NULL;
-                i->iov_len = 0;
+                *i = IOVEC_MAKE(NULL, 0);
 
                 (*idx)++;
         }
@@ -74,9 +56,7 @@ static int append_iovec(sd_bus_message *m, const void *p, size_t sz) {
         assert(p);
         assert(sz > 0);
 
-        m->iovec[m->n_iovec].iov_base = (void*) p;
-        m->iovec[m->n_iovec].iov_len = sz;
-        m->n_iovec++;
+        m->iovec[m->n_iovec++] = IOVEC_MAKE((void*) p, sz);
 
         return 0;
 }
@@ -261,16 +241,10 @@ static bool line_equals(const char *s, size_t m, const char *line) {
 }
 
 static bool line_begins(const char *s, size_t m, const char *word) {
-        size_t l;
-
-        l = strlen(word);
-        if (m < l)
-                return false;
-
-        if (memcmp(s, word, l) != 0)
-                return false;
+        const char *p;
 
-        return m == l || (m > l && s[l] == ' ');
+        p = memory_startswith(s, m, word);
+        return p && (p == (s + m) || *p == ' ');
 }
 
 static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) {
@@ -540,8 +514,7 @@ static int bus_socket_read_auth(sd_bus *b) {
 
         b->rbuffer = p;
 
-        iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size;
-        iov.iov_len = n - b->rbuffer_size;
+        iov = IOVEC_MAKE((uint8_t *)b->rbuffer + b->rbuffer_size, n - b->rbuffer_size);
 
         if (b->prefer_readv)
                 k = readv(b->input_fd, &iov, 1);
@@ -552,7 +525,7 @@ static int bus_socket_read_auth(sd_bus *b) {
                 mh.msg_control = &control;
                 mh.msg_controllen = sizeof(control);
 
-                k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
+                k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
                 if (k < 0 && errno == ENOTSOCK) {
                         b->prefer_readv = true;
                         k = readv(b->input_fd, &iov, 1);
@@ -658,12 +631,9 @@ static int bus_socket_start_auth_client(sd_bus *b) {
         else
                 auth_suffix = "\r\nBEGIN\r\n";
 
-        b->auth_iovec[0].iov_base = (void*) auth_prefix;
-        b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1);
-        b->auth_iovec[1].iov_base = (void*) b->auth_buffer;
-        b->auth_iovec[1].iov_len = l * 2;
-        b->auth_iovec[2].iov_base = (void*) auth_suffix;
-        b->auth_iovec[2].iov_len = strlen(auth_suffix);
+        b->auth_iovec[0] = IOVEC_MAKE((void*) auth_prefix, 1 + strlen(auth_prefix + 1));
+        b->auth_iovec[1] = IOVEC_MAKE(b->auth_buffer, l * 2);
+        b->auth_iovec[2] = IOVEC_MAKE_STRING(auth_suffix);
 
         return bus_socket_write_auth(b);
 }
@@ -790,7 +760,7 @@ static int bus_socket_inotify_setup(sd_bus *b) {
                         if (IN_SET(errno, ENOENT, ELOOP))
                                 break; /* This component doesn't exist yet, or the path contains a cyclic symlink right now */
 
-                        r = log_debug_errno(errno, "Failed to add inotify watch on %s: %m", isempty(prefix) ? "/" : prefix);
+                        r = log_debug_errno(errno, "Failed to add inotify watch on %s: %m", empty_to_root(prefix));
                         goto fail;
                 } else
                         new_watches[n++] = wd;
@@ -963,8 +933,7 @@ int bus_socket_exec(sd_bus *b) {
                 if (rearrange_stdio(s[1], s[1], STDERR_FILENO) < 0)
                         _exit(EXIT_FAILURE);
 
-                (void) fd_nonblock(STDIN_FILENO, false);
-                (void) fd_nonblock(STDOUT_FILENO, false);
+                (void) rlimit_nofile_safe();
 
                 if (b->exec_argv)
                         execvp(b->exec_path, b->exec_argv);
@@ -1012,7 +981,7 @@ int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) {
                 return r;
 
         n = m->n_iovec * sizeof(struct iovec);
-        iov = alloca(n);
+        iov = newa(struct iovec, n);
         memcpy_safe(iov, m->iovec, n);
 
         j = 0;
@@ -1103,7 +1072,7 @@ static int bus_socket_read_message_need(sd_bus *bus, size_t *need) {
 }
 
 static int bus_socket_make_message(sd_bus *bus, size_t size) {
-        sd_bus_message *t;
+        sd_bus_message *t = NULL;
         void *b;
         int r;
 
@@ -1128,7 +1097,9 @@ static int bus_socket_make_message(sd_bus *bus, size_t size) {
                                     bus->fds, bus->n_fds,
                                     NULL,
                                     &t);
-        if (r < 0) {
+        if (r == -EBADMSG)
+                log_debug_errno(r, "Received invalid message from connection %s, dropping.", strna(bus->description));
+        else if (r < 0) {
                 free(b);
                 return r;
         }
@@ -1139,7 +1110,8 @@ static int bus_socket_make_message(sd_bus *bus, size_t size) {
         bus->fds = NULL;
         bus->n_fds = 0;
 
-        bus->rqueue[bus->rqueue_size++] = t;
+        if (t)
+                bus->rqueue[bus->rqueue_size++] = t;
 
         return 1;
 }
@@ -1173,8 +1145,7 @@ int bus_socket_read_message(sd_bus *bus) {
 
         bus->rbuffer = b;
 
-        iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size;
-        iov.iov_len = need - bus->rbuffer_size;
+        iov = IOVEC_MAKE((uint8_t *)bus->rbuffer + bus->rbuffer_size, need - bus->rbuffer_size);
 
         if (bus->prefer_readv)
                 k = readv(bus->input_fd, &iov, 1);
@@ -1185,7 +1156,7 @@ int bus_socket_read_message(sd_bus *bus) {
                 mh.msg_control = &control;
                 mh.msg_controllen = sizeof(control);
 
-                k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
+                k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
                 if (k < 0 && errno == ENOTSOCK) {
                         bus->prefer_readv = true;
                         k = readv(bus->input_fd, &iov, 1);