This file is part of systemd.
Copyright 2010 Lennart Poettering
+ Copyright 2013 Daniel Mack
+ Copyright 2014 Kay Sievers
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
#include "bus-util.h"
#include "build.h"
#include "strv.h"
-
-#define UNIX_BUS_PATH "unix:path=/run/dbus/system_bus_socket"
-#define KERNEL_BUS_PATH "kernel:path=/dev/kdbus/0-system/bus"
-
-#ifdef ENABLE_KDBUS
-# define DEFAULT_BUS_PATH KERNEL_BUS_PATH ";" UNIX_BUS_PATH
-#else
-# define DEFAULT_BUS_PATH UNIX_BUS_PATH
-#endif
-
-static const char *arg_address = DEFAULT_BUS_PATH;
+#include "def.h"
+#include "capability.h"
+#include "bus-control.h"
+#include "smack-util.h"
+#include "set.h"
+#include "bus-xml-policy.h"
+#include "driver.h"
+#include "synthesize.h"
+
+static char *arg_address = NULL;
static char *arg_command_line_buffer = NULL;
+static bool arg_drop_privileges = false;
+static char **arg_configuration = NULL;
static int help(void) {
printf("%s [OPTIONS...]\n\n"
"Connect STDIO or a socket to a given bus address.\n\n"
- " -h --help Show this help\n"
- " --version Show package version\n"
- " --address=ADDRESS Connect to the bus specified by ADDRESS\n"
- " (default: " DEFAULT_BUS_PATH ")\n",
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ " --drop-privileges Drop privileges\n"
+ " --configuration=PATH Configuration file or directory\n"
+ " --machine=MACHINE Connect to specified machine\n"
+ " --address=ADDRESS Connect to the bus specified by ADDRESS\n"
+ " (default: " DEFAULT_SYSTEM_BUS_ADDRESS ")\n",
program_invocation_short_name);
return 0;
enum {
ARG_VERSION = 0x100,
ARG_ADDRESS,
+ ARG_DROP_PRIVILEGES,
+ ARG_CONFIGURATION,
+ ARG_MACHINE,
};
static const struct option options[] = {
- { "help", no_argument, NULL, 'h' },
- { "version", no_argument, NULL, ARG_VERSION },
- { "address", required_argument, NULL, ARG_ADDRESS },
- { NULL, 0, NULL, 0 }
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "address", required_argument, NULL, ARG_ADDRESS },
+ { "drop-privileges", no_argument, NULL, ARG_DROP_PRIVILEGES },
+ { "configuration", required_argument, NULL, ARG_CONFIGURATION },
+ { "machine", required_argument, NULL, ARG_MACHINE },
+ {},
};
- int c;
+ int c, r;
assert(argc >= 0);
assert(argv);
- while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+ while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
switch (c) {
puts(SYSTEMD_FEATURES);
return 0;
- case ARG_ADDRESS:
- arg_address = optarg;
+ case ARG_ADDRESS: {
+ char *a;
+
+ a = strdup(optarg);
+ if (!a)
+ return log_oom();
+
+ free(arg_address);
+ arg_address = a;
break;
+ }
+
+ case ARG_DROP_PRIVILEGES:
+ arg_drop_privileges = true;
+ break;
+
+ case ARG_CONFIGURATION:
+ r = strv_extend(&arg_configuration, optarg);
+ if (r < 0)
+ return log_oom();
+ break;
+
+ case ARG_MACHINE: {
+ _cleanup_free_ char *e = NULL;
+ char *a;
+
+ e = bus_address_escape(optarg);
+ if (!e)
+ return log_oom();
+
+#ifdef ENABLE_KDBUS
+ a = strjoin("x-machine-kernel:machine=", e, ";x-machine-unix:machine=", e, NULL);
+#else
+ a = strjoin("x-machine-unix:machine=", e, NULL);
+#endif
+ if (!a)
+ return log_oom();
+
+ free(arg_address);
+ arg_address = a;
+
+ break;
+ }
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
- }
/* If the first command line argument is only "x" characters
* we'll write who we are talking to into it, so that "ps" is
* explanatory */
arg_command_line_buffer = argv[optind];
- if (argc > optind + 1 ||
- (arg_command_line_buffer && arg_command_line_buffer[strspn(arg_command_line_buffer, "x")] != 0)) {
+ if (argc > optind + 1 || (arg_command_line_buffer && !in_charset(arg_command_line_buffer, "x"))) {
log_error("Too many arguments");
return -EINVAL;
}
+ if (!arg_address) {
+ arg_address = strdup(DEFAULT_SYSTEM_BUS_ADDRESS);
+ if (!arg_address)
+ return log_oom();
+ }
+
return 1;
}
assert(a);
assert(b);
- r = sd_bus_get_peer_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM, &creds);
+ r = sd_bus_get_owner_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM|SD_BUS_CREDS_AUGMENT, &creds);
if (r < 0)
return r;
/* The status string gets the full command line ... */
sd_notifyf(false,
- "STATUS=Processing requests from client PID %lu (%s); UID %lu (%s)",
- (unsigned long) pid, p,
- (unsigned long) uid, name);
+ "STATUS=Processing requests from client PID "PID_FMT" (%s); UID "UID_FMT" (%s)",
+ pid, p,
+ uid, name);
/* ... and the argv line only the short comm */
if (arg_command_line_buffer) {
m = strlen(arg_command_line_buffer);
w = snprintf(arg_command_line_buffer, m,
- "[PID %lu/%s; UID %lu/%s]",
- (unsigned long) pid, comm,
- (unsigned long) uid, name);
+ "[PID "PID_FMT"/%s; UID "UID_FMT"/%s]",
+ pid, comm,
+ uid, name);
if (m > w)
- memset(arg_command_line_buffer + w, 0, m - w);
+ memzero(arg_command_line_buffer + w, m - w);
}
- log_debug("Running on behalf of PID %lu (%s), UID %lu (%s), %s",
- (unsigned long) pid, p,
- (unsigned long) uid, name,
+ log_debug("Running on behalf of PID "PID_FMT" (%s), UID "UID_FMT" (%s), %s",
+ pid, p,
+ uid, name,
a->unique_name);
- ;
+
return 0;
}
-static int synthesize_name_acquired(sd_bus *a, sd_bus *b, sd_bus_message *m) {
- _cleanup_bus_message_unref_ sd_bus_message *n = NULL;
- const char *name, *old_owner, *new_owner;
+static int handle_policy_error(sd_bus_message *m, int r) {
+ if (r == -ESRCH || r == -ENXIO)
+ return synthetic_reply_method_errorf(m, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Name %s is currently not owned by anyone.", m->destination);
+
+ return r;
+}
+
+static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *policy, const struct ucred *our_ucred, Set *owned_names) {
int r;
- assert(a);
- assert(b);
+ assert(from);
+ assert(to);
assert(m);
- /* If we get NameOwnerChanged for our own name, we need to
- * synthesize NameLost/NameAcquired, since socket clients need
- * that, even though it is obsoleted on kdbus */
-
- if (!a->is_kernel)
+ if (!policy)
return 0;
- if (!sd_bus_message_is_signal(m, "org.freedesktop.DBus", "NameOwnerChanged") ||
- !streq_ptr(m->path, "/org/freedesktop/DBus") ||
- !streq_ptr(m->sender, "org.freedesktop.DBus"))
+ /*
+ * dbus-1 distinguishes expected and non-expected replies by tracking
+ * method-calls and timeouts. By default, DENY rules are *NEVER* applied
+ * on expected replies, unless explicitly specified. But we dont track
+ * method-calls, thus, we cannot know whether a reply is expected.
+ * Fortunately, the kdbus forbids non-expected replies, so we can safely
+ * ignore any policy on those and let the kernel deal with it.
+ *
+ * TODO: To be correct, we should only ignore policy-tags that are
+ * applied on non-expected replies. However, so far we don't parse those
+ * tags so we let everything pass. I haven't seen a DENY policy tag on
+ * expected-replies, ever, so don't bother..
+ */
+ if (m->reply_cookie > 0)
return 0;
- r = sd_bus_message_read(m, "sss", &name, &old_owner, &new_owner);
- if (r < 0)
- return r;
+ if (from->is_kernel) {
+ uid_t sender_uid = UID_INVALID;
+ gid_t sender_gid = GID_INVALID;
+ char **sender_names = NULL;
+ bool granted = false;
- r = sd_bus_message_rewind(m, true);
- if (r < 0)
- return r;
+ /* Driver messages are always OK */
+ if (streq_ptr(m->sender, "org.freedesktop.DBus"))
+ return 0;
- if (streq(old_owner, a->unique_name)) {
+ /* The message came from the kernel, and is sent to our legacy client. */
+ sd_bus_creds_get_well_known_names(&m->creds, &sender_names);
- r = sd_bus_message_new_signal(
- b,
- "/org/freedesktop/DBus",
- "org.freedesktop.DBus",
- "NameLost",
- &n);
+ (void) sd_bus_creds_get_uid(&m->creds, &sender_uid);
+ (void) sd_bus_creds_get_gid(&m->creds, &sender_gid);
- } else if (streq(new_owner, a->unique_name)) {
+ if (sender_uid == UID_INVALID || sender_gid == GID_INVALID) {
+ _cleanup_bus_creds_unref_ sd_bus_creds *sender_creds = NULL;
- r = sd_bus_message_new_signal(
- b,
- "/org/freedesktop/DBus",
- "org.freedesktop.DBus",
- "NameAcquired",
- &n);
- } else
- return 0;
+ /* If the message came from another legacy
+ * client, then the message creds will be
+ * missing, simply because on legacy clients
+ * per-message creds were unknown. In this
+ * case, query the creds of the peer
+ * instead. */
- if (r < 0)
- return r;
+ r = bus_get_name_creds_kdbus(from, m->sender, SD_BUS_CREDS_UID|SD_BUS_CREDS_GID, true, &sender_creds);
+ if (r < 0)
+ return handle_policy_error(m, r);
- r = sd_bus_message_append(n, "s", name);
- if (r < 0)
- return r;
+ (void) sd_bus_creds_get_uid(sender_creds, &sender_uid);
+ (void) sd_bus_creds_get_gid(sender_creds, &sender_gid);
+ }
- r = bus_message_append_sender(n, "org.freedesktop.DBus");
- if (r < 0)
- return r;
+ /* First check whether the sender can send the message to our name */
+ if (set_isempty(owned_names)) {
+ if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, NULL, m->path, m->interface, m->member, false))
+ granted = true;
+ } else {
+ Iterator i;
+ char *n;
+
+ SET_FOREACH(n, owned_names, i)
+ if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, n, m->path, m->interface, m->member, false)) {
+ granted = true;
+ break;
+ }
+ }
- r = bus_seal_synthetic_message(b, n);
- if (r < 0)
- return r;
+ if (granted) {
+ /* Then check whether us (the recipient) can receive from the sender's name */
+ if (strv_isempty(sender_names)) {
+ if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member, false))
+ return 0;
+ } else {
+ char **n;
+
+ STRV_FOREACH(n, sender_names) {
+ if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member, false))
+ return 0;
+ }
+ }
+ }
+
+ /* Return an error back to the caller */
+ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+ return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML receiver policy.");
+
+ /* Return 1, indicating that the message shall not be processed any further */
+ return 1;
+ }
+
+ if (to->is_kernel) {
+ _cleanup_bus_creds_unref_ sd_bus_creds *destination_creds = NULL;
+ uid_t destination_uid = UID_INVALID;
+ gid_t destination_gid = GID_INVALID;
+ const char *destination_unique = NULL;
+ char **destination_names = NULL;
+ bool granted = false;
+
+ /* Driver messages are always OK */
+ if (streq_ptr(m->destination, "org.freedesktop.DBus"))
+ return 0;
+
+ /* The message came from the legacy client, and is sent to kdbus. */
+ if (m->destination) {
+ r = bus_get_name_creds_kdbus(to, m->destination,
+ SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME|
+ SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID,
+ true, &destination_creds);
+ if (r < 0)
+ return handle_policy_error(m, r);
+
+ r = sd_bus_creds_get_unique_name(destination_creds, &destination_unique);
+ if (r < 0)
+ return handle_policy_error(m, r);
+
+ sd_bus_creds_get_well_known_names(destination_creds, &destination_names);
- return sd_bus_send(b, n, NULL);
+ (void) sd_bus_creds_get_uid(destination_creds, &destination_uid);
+ (void) sd_bus_creds_get_gid(destination_creds, &destination_gid);
+ }
+
+ /* First check if we (the sender) can send to this name */
+ if (strv_isempty(destination_names)) {
+ if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member, true))
+ granted = true;
+ } else {
+ char **n;
+
+ STRV_FOREACH(n, destination_names) {
+ if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member, true)) {
+
+ /* If we made a receiver decision,
+ then remember which name's policy
+ we used, and to which unique ID it
+ mapped when we made the
+ decision. Then, let's pass this to
+ the kernel when sending the
+ message, so that it refuses the
+ operation should the name and
+ unique ID not map to each other
+ anymore. */
+
+ r = free_and_strdup(&m->destination_ptr, *n);
+ if (r < 0)
+ return r;
+
+ r = bus_kernel_parse_unique_name(destination_unique, &m->verify_destination_id);
+ if (r < 0)
+ break;
+
+ granted = true;
+ break;
+ }
+ }
+ }
+
+ /* Then check if the recipient can receive from our name */
+ if (granted) {
+ if (sd_bus_message_is_signal(m, NULL, NULL)) {
+ /* If we forward a signal from dbus-1 to kdbus,
+ * we have no idea who the recipient is.
+ * Therefore, we cannot apply any dbus-1
+ * receiver policies that match on receiver
+ * credentials. We know sd-bus always sets
+ * KDBUS_MSG_SIGNAL, so the kernel applies
+ * receiver policies to the message. Therefore,
+ * skip policy checks in this case. */
+ return 0;
+ } else if (set_isempty(owned_names)) {
+ if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, NULL, m->path, m->interface, m->member, true))
+ return 0;
+ } else {
+ Iterator i;
+ char *n;
+
+ SET_FOREACH(n, owned_names, i)
+ if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, n, m->path, m->interface, m->member, true))
+ return 0;
+ }
+ }
+
+ /* Return an error back to the caller */
+ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+ return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML sender policy.");
+
+ /* Return 1, indicating that the message shall not be processed any further */
+ return 1;
+ }
+
+ return 0;
}
static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hello) {
return 0;
r = sd_bus_message_new_method_return(m, &n);
- if (r < 0) {
- log_error("Failed to generate HELLO reply: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate HELLO reply: %m");
r = sd_bus_message_append(n, "s", a->unique_name);
- if (r < 0) {
- log_error("Failed to append unique name to HELLO reply: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to append unique name to HELLO reply: %m");
r = bus_message_append_sender(n, "org.freedesktop.DBus");
- if (r < 0) {
- log_error("Failed to append sender to HELLO reply: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to append sender to HELLO reply: %m");
r = bus_seal_synthetic_message(b, n);
- if (r < 0) {
- log_error("Failed to seal HELLO reply: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to seal HELLO reply: %m");
r = sd_bus_send(b, n, NULL);
- if (r < 0) {
- log_error("Failed to send HELLO reply: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to send HELLO reply: %m");
n = sd_bus_message_unref(n);
r = sd_bus_message_new_signal(
b,
+ &n,
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
- "NameAcquired",
- &n);
- if (r < 0) {
- log_error("Failed to allocate initial NameAcquired message: %s", strerror(-r));
- return r;
- }
+ "NameAcquired");
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate initial NameAcquired message: %m");
r = sd_bus_message_append(n, "s", a->unique_name);
- if (r < 0) {
- log_error("Failed to append unique name to NameAcquired message: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to append unique name to NameAcquired message: %m");
r = bus_message_append_sender(n, "org.freedesktop.DBus");
- if (r < 0) {
- log_error("Failed to append sender to NameAcquired message: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to append sender to NameAcquired message: %m");
r = bus_seal_synthetic_message(b, n);
- if (r < 0) {
- log_error("Failed to seal NameAcquired message: %s", strerror(-r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to seal NameAcquired message: %m");
r = sd_bus_send(b, n, NULL);
- if (r < 0) {
- log_error("Failed to send NameAcquired message: %s", strerror(-r));
+ if (r < 0)
+ return log_error_errno(r, "Failed to send NameAcquired message: %m");
+
+ return 1;
+}
+
+static int patch_sender(sd_bus *a, sd_bus_message *m) {
+ char **well_known = NULL;
+ sd_bus_creds *c;
+ int r;
+
+ assert(a);
+ assert(m);
+
+ if (!a->is_kernel)
+ return 0;
+
+ /* We will change the sender of messages from the bus driver
+ * so that they originate from the bus driver. This is a
+ * speciality originating from dbus1, where the bus driver did
+ * not have a unique id, but only the well-known name. */
+
+ c = sd_bus_message_get_creds(m);
+ if (!c)
+ return 0;
+
+ r = sd_bus_creds_get_well_known_names(c, &well_known);
+ if (r < 0)
return r;
+
+ if (strv_contains(well_known, "org.freedesktop.DBus"))
+ m->sender = "org.freedesktop.DBus";
+
+ return 0;
+}
+
+static int bus_new_destination(sd_bus **out, struct ucred *ucred, const char *peersec, bool negotiate_fds) {
+ _cleanup_bus_close_unref_ sd_bus *a = NULL;
+ int r;
+
+ r = sd_bus_new(&a);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate bus: %m");
+
+ r = sd_bus_set_description(a, "sd-proxy");
+ if (r < 0)
+ return log_error_errno(r, "Failed to set bus name: %m");
+
+ r = sd_bus_set_address(a, arg_address);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set address to connect to: %m");
+
+ r = sd_bus_negotiate_fds(a, negotiate_fds);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set FD negotiation: %m");
+
+ r = sd_bus_negotiate_creds(a, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set credential negotiation: %m");
+
+ if (ucred->pid > 0) {
+ a->fake_pids.pid = ucred->pid;
+ a->fake_pids_valid = true;
+
+ a->fake_creds.uid = ucred->uid;
+ a->fake_creds.euid = UID_INVALID;
+ a->fake_creds.suid = UID_INVALID;
+ a->fake_creds.fsuid = UID_INVALID;
+ a->fake_creds.gid = ucred->gid;
+ a->fake_creds.egid = GID_INVALID;
+ a->fake_creds.sgid = GID_INVALID;
+ a->fake_creds.fsgid = GID_INVALID;
+ a->fake_creds_valid = true;
}
- return 1;
+ if (peersec) {
+ a->fake_label = strdup(peersec);
+ if (!a->fake_label)
+ return log_oom();
+ }
+
+ a->manual_peer_interface = true;
+
+ r = sd_bus_start(a);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start bus client: %m");
+
+ *out = a;
+ a = NULL;
+ return 0;
+}
+
+static int bus_new_local(sd_bus **out, sd_bus *dest, int in_fd, int out_fd, bool negotiate_fds) {
+ _cleanup_bus_close_unref_ sd_bus *b = NULL;
+ sd_id128_t server_id;
+ int r;
+
+ r = sd_bus_new(&b);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate bus: %m");
+
+ r = sd_bus_set_fd(b, in_fd, out_fd);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set fds: %m");
+
+ r = sd_bus_get_bus_id(dest, &server_id);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get server ID: %m");
+
+ r = sd_bus_set_server(b, 1, server_id);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set server mode: %m");
+
+ r = sd_bus_negotiate_fds(b, negotiate_fds);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set FD negotiation: %m");
+
+ r = sd_bus_negotiate_creds(b, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set credential negotiation: %m");
+
+ r = sd_bus_set_anonymous(b, true);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set anonymous authentication: %m");
+
+ b->manual_peer_interface = true;
+
+ r = sd_bus_start(b);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start bus client: %m");
+
+ *out = b;
+ b = NULL;
+ return 0;
}
+static int mac_smack_apply_label_and_drop_cap_mac_admin(pid_t its_pid, const char *new_label) {
+#ifdef HAVE_SMACK
+ int r = 0, k;
+
+ if (!mac_smack_use())
+ return 0;
+
+ if (new_label && its_pid > 0)
+ r = mac_smack_apply_pid(its_pid, new_label);
+
+ k = drop_capability(CAP_MAC_ADMIN);
+ return r < 0 ? r : k;
+#else
+ return 0;
+#endif
+}
+
+
int main(int argc, char *argv[]) {
- _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL;
- sd_id128_t server_id;
+ _cleanup_bus_close_unref_ sd_bus *a = NULL, *b = NULL;
int r, in_fd, out_fd;
bool got_hello = false;
bool is_unix;
struct ucred ucred = {};
_cleanup_free_ char *peersec = NULL;
+ Policy policy_buffer = {}, *policy = NULL;
+ _cleanup_set_free_free_ Set *owned_names = NULL;
+ uid_t original_uid;
log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
log_parse_environment();
goto finish;
}
+ original_uid = getuid();
+
is_unix =
sd_is_socket(in_fd, AF_UNIX, 0, 0) > 0 &&
sd_is_socket(out_fd, AF_UNIX, 0, 0) > 0;
if (is_unix) {
- getpeercred(in_fd, &ucred);
- getpeersec(in_fd, &peersec);
- }
-
- r = sd_bus_new(&a);
- if (r < 0) {
- log_error("Failed to allocate bus: %s", strerror(-r));
- goto finish;
- }
+ (void) getpeercred(in_fd, &ucred);
+ (void) getpeersec(in_fd, &peersec);
- r = sd_bus_set_address(a, arg_address);
- if (r < 0) {
- log_error("Failed to set address to connect to: %s", strerror(-r));
- goto finish;
+ r = mac_smack_apply_label_and_drop_cap_mac_admin(getpid(), peersec);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SMACK label (%s) and drop CAP_MAC_ADMIN: %m", peersec);
}
- r = sd_bus_negotiate_fds(a, is_unix);
- if (r < 0) {
- log_error("Failed to set FD negotiation: %s", strerror(-r));
- goto finish;
- }
+ if (arg_drop_privileges) {
+ const char *user = "systemd-bus-proxy";
+ uid_t uid;
+ gid_t gid;
- if (ucred.pid > 0) {
- a->fake_creds.pid = ucred.pid;
- a->fake_creds.uid = ucred.uid;
- a->fake_creds.gid = ucred.gid;
- a->fake_creds_valid = true;
- }
+ r = get_user_creds(&user, &uid, &gid, NULL, NULL);
+ if (r < 0) {
+ log_error_errno(r, "Cannot resolve user name %s: %m", user);
+ goto finish;
+ }
- if (peersec) {
- a->fake_label = peersec;
- peersec = NULL;
+ r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER);
+ if (r < 0)
+ goto finish;
}
- a->manual_peer_interface = true;
-
- r = sd_bus_start(a);
- if (r < 0) {
- log_error("Failed to start bus client: %s", strerror(-r));
+ owned_names = set_new(&string_hash_ops);
+ if (!owned_names) {
+ log_oom();
goto finish;
}
- r = sd_bus_get_server_id(a, &server_id);
- if (r < 0) {
- log_error("Failed to get server ID: %s", strerror(-r));
+ r = bus_new_destination(&a, &ucred, peersec, is_unix);
+ if (r < 0)
goto finish;
- }
- r = sd_bus_new(&b);
- if (r < 0) {
- log_error("Failed to allocate bus: %s", strerror(-r));
- goto finish;
- }
+ if (a->is_kernel) {
+ if (!arg_configuration) {
+ const char *scope;
- r = sd_bus_set_fd(b, in_fd, out_fd);
- if (r < 0) {
- log_error("Failed to set fds: %s", strerror(-r));
- goto finish;
- }
+ r = sd_bus_get_scope(a, &scope);
+ if (r < 0) {
+ log_error_errno(r, "Couldn't determine bus scope: %m");
+ goto finish;
+ }
- r = sd_bus_set_server(b, 1, server_id);
- if (r < 0) {
- log_error("Failed to set server mode: %s", strerror(-r));
- goto finish;
- }
+ if (streq(scope, "system"))
+ arg_configuration = strv_new(
+ "/etc/dbus-1/system.conf",
+ "/etc/dbus-1/system.d/",
+ "/etc/dbus-1/system-local.conf",
+ NULL);
+ else if (streq(scope, "user"))
+ arg_configuration = strv_new(
+ "/etc/dbus-1/session.conf",
+ "/etc/dbus-1/session.d/",
+ "/etc/dbus-1/session-local.conf",
+ NULL);
+ else {
+ log_error("Unknown scope %s, don't know which policy to load. Refusing.", scope);
+ goto finish;
+ }
- r = sd_bus_negotiate_fds(b, is_unix);
- if (r < 0) {
- log_error("Failed to set FD negotiation: %s", strerror(-r));
- goto finish;
- }
+ if (!arg_configuration) {
+ r = log_oom();
+ goto finish;
+ }
+ }
- r = sd_bus_set_anonymous(b, true);
- if (r < 0) {
- log_error("Failed to set anonymous authentication: %s", strerror(-r));
- goto finish;
- }
+ r = policy_load(&policy_buffer, arg_configuration);
+ if (r < 0) {
+ log_error_errno(r, "Failed to load policy: %m");
+ goto finish;
+ }
- b->manual_peer_interface = true;
+ policy = &policy_buffer;
+ /* policy_dump(policy); */
- r = sd_bus_start(b);
- if (r < 0) {
- log_error("Failed to start bus client: %s", strerror(-r));
- goto finish;
+ if (ucred.uid == original_uid)
+ log_debug("Permitting access, since bus owner matches bus client.");
+ else if (policy_check_hello(policy, ucred.uid, ucred.gid))
+ log_debug("Permitting access due to XML policy.");
+ else {
+ r = log_error_errno(EPERM, "Policy denied connection.");
+ goto finish;
+ }
}
+ r = bus_new_local(&b, a, in_fd, out_fd, is_unix);
+ if (r < 0)
+ goto finish;
+
r = rename_service(a, b);
if (r < 0)
- log_debug("Failed to rename process: %s", strerror(-r));
+ log_debug_errno(r, "Failed to rename process: %m");
if (a->is_kernel) {
_cleanup_free_ char *match = NULL;
r = sd_bus_get_unique_name(a, &unique);
if (r < 0) {
- log_error("Failed to get unique name: %s", strerror(-r));
+ log_error_errno(r, "Failed to get unique name: %m");
goto finish;
}
goto finish;
}
- r = sd_bus_add_match(a, match, NULL, NULL);
+ r = sd_bus_add_match(a, NULL, match, NULL, NULL);
if (r < 0) {
- log_error("Failed to add match for NameLost: %s", strerror(-r));
+ log_error_errno(r, "Failed to add match for NameLost: %m");
goto finish;
}
goto finish;
}
- r = sd_bus_add_match(a, match, NULL, NULL);
+ r = sd_bus_add_match(a, NULL, match, NULL, NULL);
if (r < 0) {
- log_error("Failed to add match for NameAcquired: %s", strerror(-r));
+ log_error_errno(r, "Failed to add match for NameAcquired: %m");
goto finish;
}
}
int k;
if (got_hello) {
+ /* Read messages from bus, to pass them on to our client */
+
r = sd_bus_process(a, &m);
if (r < 0) {
/* treat 'connection reset by peer' as clean exit condition */
if (r == -ECONNRESET)
r = 0;
else
- log_error("Failed to process bus a: %s", strerror(-r));
+ log_error_errno(r, "Failed to process bus a: %m");
goto finish;
}
if (m) {
+ bool processed = false;
+
/* We officially got EOF, let's quit */
if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
r = 0;
k = synthesize_name_acquired(a, b, m);
if (k < 0) {
r = k;
- log_error("Failed to synthesize message: %s", strerror(-r));
+ log_error_errno(r, "Failed to synthesize message: %m");
goto finish;
}
- k = sd_bus_send(b, m, NULL);
- if (k < 0) {
- r = k;
- log_error("Failed to send message: %s", strerror(-r));
- goto finish;
+ patch_sender(a, m);
+
+ if (policy) {
+ k = process_policy(a, b, m, policy, &ucred, owned_names);
+ if (k < 0) {
+ r = k;
+ log_error_errno(r, "Failed to process policy: %m");
+ goto finish;
+ } else if (k > 0) {
+ r = 1;
+ processed = true;
+ }
+ }
+
+ if (!processed) {
+ k = sd_bus_send(b, m, NULL);
+ if (k < 0) {
+ if (k == -ECONNRESET) {
+ r = 0;
+ goto finish;
+ } else if (k == -EPERM && m->reply_cookie > 0) {
+ /* If the peer tries to send a reply and it is rejected with EPERM
+ * by the kernel, we ignore the error. This catches cases where the
+ * original method-call didn't had EXPECT_REPLY set, but the proxy-peer
+ * still sends a reply. This is allowed in dbus1, but not in kdbus. We
+ * don't want to track reply-windows in the proxy, so we simply ignore
+ * EPERM for all replies. The only downside is, that callers are no
+ * longer notified if their replies are dropped. However, this is
+ * equivalent to the caller's timeout to expire, so this should be
+ * acceptable. Nobody sane sends replies without a matching method-call,
+ * so nobody should care. */
+ r = 1;
+ } else {
+ r = k;
+ log_error_errno(r, "Failed to send message to client: %m");
+ goto finish;
+ }
+ } else
+ r = 1;
}
}
continue;
}
+ /* Read messages from our client, to pass them on to the bus */
r = sd_bus_process(b, &m);
if (r < 0) {
/* treat 'connection reset by peer' as clean exit condition */
if (r == -ECONNRESET)
r = 0;
else
- log_error("Failed to process bus b: %s", strerror(-r));
+ log_error_errno(r, "Failed to process bus b: %m");
goto finish;
}
if (m) {
+ bool processed = false;
+
/* We officially got EOF, let's quit */
if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
r = 0;
k = process_hello(a, b, m, &got_hello);
if (k < 0) {
r = k;
+ log_error_errno(r, "Failed to process HELLO: %m");
goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
}
- if (k > 0)
- r = k;
- else {
- k = sd_bus_send(a, m, NULL);
+ if (!processed) {
+ k = bus_proxy_process_driver(a, b, m, policy, &ucred, owned_names);
if (k < 0) {
r = k;
- log_error("Failed to send message: %s", strerror(-r));
+ log_error_errno(r, "Failed to process driver calls: %m");
goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
+ }
+
+ if (!processed) {
+
+ for (;;) {
+ if (policy) {
+ k = process_policy(b, a, m, policy, &ucred, owned_names);
+ if (k < 0) {
+ r = k;
+ log_error_errno(r, "Failed to process policy: %m");
+ goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
+ break;
+ }
+ }
+
+ k = sd_bus_send(a, m, NULL);
+ if (k < 0) {
+ if (k == -EREMCHG) {
+ /* The name database changed since the policy check, hence let's check again */
+ continue;
+ } else if (k == -ECONNRESET) {
+ r = 0;
+ goto finish;
+ } else if (k == -EPERM && m->reply_cookie > 0) {
+ /* see above why EPERM is ignored for replies */
+ r = 1;
+ } else {
+ r = k;
+ log_error_errno(r, "Failed to send message to bus: %m");
+ goto finish;
+ }
+ } else
+ r = 1;
+
+ break;
+ }
}
}
}
fd = sd_bus_get_fd(a);
if (fd < 0) {
- log_error("Failed to get fd: %s", strerror(-r));
+ log_error_errno(r, "Failed to get fd: %m");
goto finish;
}
events_a = sd_bus_get_events(a);
if (events_a < 0) {
- log_error("Failed to get events mask: %s", strerror(-r));
+ log_error_errno(r, "Failed to get events mask: %m");
goto finish;
}
r = sd_bus_get_timeout(a, &timeout_a);
if (r < 0) {
- log_error("Failed to get timeout: %s", strerror(-r));
+ log_error_errno(r, "Failed to get timeout: %m");
goto finish;
}
events_b = sd_bus_get_events(b);
if (events_b < 0) {
- log_error("Failed to get events mask: %s", strerror(-r));
+ log_error_errno(r, "Failed to get events mask: %m");
goto finish;
}
r = sd_bus_get_timeout(b, &timeout_b);
if (r < 0) {
- log_error("Failed to get timeout: %s", strerror(-r));
+ log_error_errno(r, "Failed to get timeout: %m");
goto finish;
}
r = ppoll(pollfd, 3, ts, NULL);
if (r < 0) {
- log_error("ppoll() failed: %m");
+ log_error_errno(errno, "ppoll() failed: %m");
goto finish;
}
}
- r = 0;
-
finish:
- sd_bus_flush(a);
- sd_bus_flush(b);
+ sd_notify(false,
+ "STOPPING=1\n"
+ "STATUS=Shutting down.");
+
+ policy_free(&policy_buffer);
+ strv_free(arg_configuration);
+ free(arg_address);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
~ianmdlvl / elogind.git / blobdiff