X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbus-proxyd%2Fbus-proxyd.c;h=3cbbab718bd139bed498e67ce2c5857e606d6998;hp=3fc341eaed7a47407f5c526f0e5c9889f25b1200;hb=0042d824e3616aaf2e3eec23d3b2e6aec7c0470c;hpb=2a2be74654f0511220cf9a8a72f60ab5705abb87 diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c index 3fc341eae..3cbbab718 100644 --- a/src/bus-proxyd/bus-proxyd.c +++ b/src/bus-proxyd/bus-proxyd.c @@ -44,15 +44,16 @@ #include "strv.h" #include "def.h" #include "capability.h" -#include "bus-policy.h" +#include "bus-control.h" +#include "smack-util.h" +#include "set.h" +#include "bus-xml-policy.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 Hashmap *names_hash = NULL; - static int help(void) { printf("%s [OPTIONS...]\n\n" @@ -63,7 +64,7 @@ static int help(void) { " --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_PATH ")\n", + " (default: " DEFAULT_SYSTEM_BUS_ADDRESS ")\n", program_invocation_short_name); return 0; @@ -138,9 +139,9 @@ static int parse_argv(int argc, char *argv[]) { return log_oom(); #ifdef ENABLE_KDBUS - a = strjoin("x-container-kernel:machine=", e, ";x-container-unix:machine=", e, NULL); + a = strjoin("x-machine-kernel:machine=", e, ";x-machine-unix:machine=", e, NULL); #else - a = strjoin("x-container-unix:machine=", e, NULL); + a = strjoin("x-machine-unix:machine=", e, NULL); #endif if (!a) return log_oom(); @@ -168,7 +169,7 @@ static int parse_argv(int argc, char *argv[]) { } if (!arg_address) { - arg_address = strdup(DEFAULT_SYSTEM_BUS_PATH); + arg_address = strdup(DEFAULT_SYSTEM_BUS_ADDRESS); if (!arg_address) return log_oom(); } @@ -188,7 +189,7 @@ static int rename_service(sd_bus *a, sd_bus *b) { assert(a); assert(b); - r = sd_bus_get_owner_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; @@ -344,6 +345,17 @@ static int synthetic_reply_method_error(sd_bus_message *call, const sd_bus_error return synthetic_driver_send(call->bus, m); } +static int synthetic_reply_method_errorf(sd_bus_message *call, const char *name, const char *format, ...) { + _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; + va_list ap; + + va_start(ap, format); + bus_error_setfv(&error, name, format, ap); + va_end(ap); + + return synthetic_reply_method_error(call, &error); +} + static int synthetic_reply_method_errno(sd_bus_message *call, int error, const sd_bus_error *p) { _cleanup_bus_error_free_ sd_bus_error berror = SD_BUS_ERROR_NULL; @@ -393,6 +405,9 @@ static int synthetic_reply_return_strv(sd_bus_message *call, char **l) { assert(call); + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + r = sd_bus_message_new_method_return(call, &m); if (r < 0) return synthetic_reply_method_errno(call, r, NULL); @@ -412,8 +427,6 @@ static int get_creds_by_name(sd_bus *bus, const char *name, uint64_t mask, sd_bu assert(name); assert(_creds); - assert_return(service_name_is_valid(name), -EINVAL); - r = sd_bus_get_name_creds(bus, name, mask, &c); if (r == -ESRCH || r == -ENXIO) return sd_bus_error_setf(error, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Name %s is currently not owned by anyone.", name); @@ -444,62 +457,7 @@ static int get_creds_by_message(sd_bus *bus, sd_bus_message *m, uint64_t mask, s return get_creds_by_name(bus, name, mask, _creds, error); } -static int peer_is_privileged(sd_bus *bus, sd_bus_message *m) { - _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL; - uid_t uid; - int r; - - r = get_creds_by_message(bus, m, SD_BUS_CREDS_UID, &creds, NULL); - if (r < 0) - return r; - - r = sd_bus_creds_get_uid(creds, &uid); - if (r < 0) - return r; - - r = sd_bus_creds_has_effective_cap(creds, CAP_SYS_ADMIN); - if (r > 0) - return true; - - if (uid == getuid()) - return true; - - return false; -} - -static int process_policy(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) { - int r; - char **names_strv; - - assert(a); - assert(b); - assert(m); - - if (b->is_kernel) { - - /* The message came from the kernel, and is sent to our legacy client. */ - r = sd_bus_creds_get_well_known_names(&m->creds, &names_strv); - if (r < 0) - return r; - -/* - if (!policy_check_recv(policy, ucred, names_hash, m->header->type, m->path, m->interface, m->member)) - return -EPERM; - - if (!policy_check_send(policy, ucred, names_strv, m->header->type, m->path, m->interface, m->member)) - return -EPERM; -*/ - } else { - - - - - } - - return 0; -} - -static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) { +static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, Set *owned_names) { int r; assert(a); @@ -512,14 +470,12 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic if (!streq_ptr(sd_bus_message_get_destination(m), "org.freedesktop.DBus")) return 0; - if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) { - if (0 && !isempty(sd_bus_message_get_signature(m, true))) { - _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; + /* The "Hello()" call is is handled in process_hello() */ - r = sd_bus_error_setf(&error, SD_BUS_ERROR_INVALID_ARGS, "Expected no parameters"); + if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) { - return synthetic_reply_method_errno(m, r, &error); - } + if (!sd_bus_message_has_signature(m, "")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); return synthetic_reply_method_return(m, "s", "unique_name); - /* "Hello" is handled in process_hello() */ - } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListActivatableNames")) { _cleanup_strv_free_ char **names = NULL; + if (!sd_bus_message_has_signature(m, "")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_list_names(a, NULL, &names); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); @@ -709,6 +687,9 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListNames")) { _cleanup_strv_free_ char **names = NULL; + if (!sd_bus_message_has_signature(m, "")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_list_names(a, &names, NULL); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); @@ -725,20 +706,19 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListQueuedOwners")) { struct kdbus_cmd_name_list cmd = {}; struct kdbus_name_list *name_list; - struct kdbus_cmd_free cmd_free; struct kdbus_name_info *name; _cleanup_strv_free_ char **owners = NULL; _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; char *arg0; int err = 0; + if (!sd_bus_message_has_signature(m, "s")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_message_read(m, "s", &arg0); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); - if (!service_name_is_valid(arg0)) - return synthetic_reply_method_errno(m, -EINVAL, NULL); - r = sd_bus_get_name_creds(a, arg0, 0, NULL); if (r == -ESRCH || r == -ENXIO) { sd_bus_error_setf(&error, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Could not get owners of name '%s': no such name.", arg0); @@ -778,10 +758,7 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } } - cmd_free.flags = 0; - cmd_free.offset = cmd.offset; - - r = ioctl(a->input_fd, KDBUS_CMD_FREE, &cmd_free); + r = bus_kernel_cmd_free(a, cmd.offset); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); @@ -793,13 +770,13 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "NameHasOwner")) { const char *name; + if (!sd_bus_message_has_signature(m, "s")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_message_read(m, "s", &name); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); - if (!service_name_is_valid(name)) - return synthetic_reply_method_errno(m, -EINVAL, NULL); - if (streq(name, "org.freedesktop.DBus")) return synthetic_reply_method_return(m, "b", true); @@ -812,13 +789,13 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ReleaseName")) { const char *name; + if (!sd_bus_message_has_signature(m, "s")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_message_read(m, "s", &name); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); - if (!service_name_is_valid(name)) - return synthetic_reply_method_errno(m, -EINVAL, NULL); - r = sd_bus_release_name(a, name); if (r < 0) { if (r == -ESRCH) @@ -829,13 +806,16 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic return synthetic_reply_method_errno(m, r, NULL); } - hashmap_remove(names_hash, name); + set_remove(owned_names, (char*) name); return synthetic_reply_method_return(m, "u", BUS_NAME_RELEASED); } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ReloadConfig")) { _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; + if (!sd_bus_message_has_signature(m, "")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_error_setf(&error, SD_BUS_ERROR_NOT_SUPPORTED, "%s() is not supported", sd_bus_message_get_member(m)); return synthetic_reply_method_errno(m, r, &error); @@ -845,15 +825,16 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic uint32_t flags, param; bool in_queue; + if (!sd_bus_message_has_signature(m, "su")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_message_read(m, "su", &name, &flags); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); - if (!policy_check_own(policy, ucred, name)) + if (policy && !policy_check_own(policy, ucred->uid, ucred->gid, name)) return synthetic_reply_method_errno(m, -EPERM, NULL); - if (!service_name_is_valid(name)) - return synthetic_reply_method_errno(m, -EINVAL, NULL); if ((flags & ~(BUS_NAME_ALLOW_REPLACEMENT|BUS_NAME_REPLACE_EXISTING|BUS_NAME_DO_NOT_QUEUE)) != 0) return synthetic_reply_method_errno(m, -EINVAL, NULL); @@ -865,21 +846,24 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic if (!(flags & BUS_NAME_DO_NOT_QUEUE)) param |= SD_BUS_NAME_QUEUE; + r = set_put_strdup(owned_names, name); + if (r < 0) + return synthetic_reply_method_errno(m, r, NULL); + r = sd_bus_request_name(a, name, param); if (r < 0) { - if (r == -EEXIST) - return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS); if (r == -EALREADY) return synthetic_reply_method_return(m, "u", BUS_NAME_ALREADY_OWNER); + + set_remove(owned_names, (char*) name); + + if (r == -EEXIST) + return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS); return synthetic_reply_method_errno(m, r, NULL); } in_queue = (r == 0); - r = hashmap_put(names_hash, name, NULL); - if (r < 0) - return synthetic_reply_method_errno(m, r, NULL); - if (in_queue) return synthetic_reply_method_return(m, "u", BUS_NAME_IN_QUEUE); @@ -890,12 +874,13 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic const char *name; uint32_t flags; + if (!sd_bus_message_has_signature(m, "su")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); + r = sd_bus_message_read(m, "su", &name, &flags); if (r < 0) return synthetic_reply_method_errno(m, r, NULL); - if (!service_name_is_valid(name)) - return synthetic_reply_method_errno(m, -EINVAL, NULL); if (flags != 0) return synthetic_reply_method_errno(m, -EINVAL, NULL); @@ -925,8 +910,8 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic _cleanup_bus_message_unref_ sd_bus_message *msg = NULL; _cleanup_strv_free_ char **args = NULL; - if (!peer_is_privileged(a, m)) - return synthetic_reply_method_errno(m, -EPERM, NULL); + if (!sd_bus_message_has_signature(m, "a{ss}")) + return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters")); r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "{ss}"); if (r < 0) @@ -990,7 +975,204 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic } } -static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, bool *got_hello) { +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(from); + assert(to); + assert(m); + + if (!policy) + return 0; + + /* + * 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; + + if (from->is_kernel) { + uid_t sender_uid = UID_INVALID; + gid_t sender_gid = GID_INVALID; + char **sender_names = NULL; + bool granted = false; + + /* Driver messages are always OK */ + if (streq_ptr(m->sender, "org.freedesktop.DBus")) + return 0; + + /* The message came from the kernel, and is sent to our legacy client. */ + sd_bus_creds_get_well_known_names(&m->creds, &sender_names); + + (void) sd_bus_creds_get_uid(&m->creds, &sender_uid); + (void) sd_bus_creds_get_gid(&m->creds, &sender_gid); + + if (sender_uid == UID_INVALID || sender_gid == GID_INVALID) { + _cleanup_bus_creds_unref_ sd_bus_creds *sender_creds = NULL; + + /* 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. */ + + 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); + + (void) sd_bus_creds_get_uid(sender_creds, &sender_uid); + (void) sd_bus_creds_get_gid(sender_creds, &sender_gid); + } + + /* 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)) + 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)) { + granted = true; + break; + } + } + + 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)) + 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)) + 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); + + (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)) + 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)) { + + /* 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 (set_isempty(owned_names)) { + if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, NULL, m->path, m->interface, m->member)) + 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)) + 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) { _cleanup_bus_message_unref_ sd_bus_message *n = NULL; bool is_hello; int r; @@ -1022,45 +1204,30 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy return -EIO; } - if (!policy_check_hello(policy, ucred)) { - log_error("Policy denied HELLO"); - return -EPERM; - } - *got_hello = true; if (!a->is_kernel) 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( @@ -1069,34 +1236,24 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy "/org/freedesktop/DBus", "org.freedesktop.DBus", "NameAcquired"); - if (r < 0) { - log_error("Failed to allocate initial NameAcquired message: %s", strerror(-r)); - return r; - } + 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)); - return r; - } + if (r < 0) + return log_error_errno(r, "Failed to send NameAcquired message: %m"); return 1; } @@ -1131,6 +1288,23 @@ static int patch_sender(sd_bus *a, sd_bus_message *m) { 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_close_unref_ sd_bus *a = NULL, *b = NULL; @@ -1140,7 +1314,9 @@ int main(int argc, char *argv[]) { bool is_unix; struct ucred ucred = {}; _cleanup_free_ char *peersec = NULL; - Policy policy = {}; + 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(); @@ -1150,14 +1326,6 @@ int main(int argc, char *argv[]) { if (r <= 0) goto finish; - r = policy_load(&policy, arg_configuration); - if (r < 0) { - log_error("Failed to load policy: %s", strerror(-r)); - goto finish; - } - - /* policy_dump(&policy); */ - r = sd_listen_fds(0); if (r == 0) { in_fd = STDIN_FILENO; @@ -1170,6 +1338,8 @@ int main(int argc, char *argv[]) { 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; @@ -1177,6 +1347,10 @@ int main(int argc, char *argv[]) { if (is_unix) { (void) getpeercred(in_fd, &ucred); (void) getpeersec(in_fd, &peersec); + + 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); } if (arg_drop_privileges) { @@ -1186,7 +1360,7 @@ int main(int argc, char *argv[]) { r = get_user_creds(&user, &uid, &gid, NULL, NULL); if (r < 0) { - log_error("Cannot resolve user name %s: %s", user, strerror(-r)); + log_error_errno(r, "Cannot resolve user name %s: %m", user); goto finish; } @@ -1195,40 +1369,54 @@ int main(int argc, char *argv[]) { goto finish; } - names_hash = hashmap_new(&string_hash_ops); - if (!names_hash) { + owned_names = set_new(&string_hash_ops); + if (!owned_names) { log_oom(); goto finish; } r = sd_bus_new(&a); if (r < 0) { - log_error("Failed to allocate bus: %s", strerror(-r)); + log_error_errno(r, "Failed to allocate bus: %m"); goto finish; } r = sd_bus_set_description(a, "sd-proxy"); if (r < 0) { - log_error("Failed to set bus name: %s", strerror(-r)); + log_error_errno(r, "Failed to set bus name: %m"); goto finish; } r = sd_bus_set_address(a, arg_address); if (r < 0) { - log_error("Failed to set address to connect to: %s", strerror(-r)); + log_error_errno(r, "Failed to set address to connect to: %m"); goto finish; } r = sd_bus_negotiate_fds(a, is_unix); if (r < 0) { - log_error("Failed to set FD negotiation: %s", strerror(-r)); + log_error_errno(r, "Failed to set FD negotiation: %m"); + goto finish; + } + + 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) { + log_error_errno(r, "Failed to set credential negotiation: %m"); goto finish; } if (ucred.pid > 0) { - a->fake_creds.pid = ucred.pid; + 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; } @@ -1241,43 +1429,101 @@ int main(int argc, char *argv[]) { r = sd_bus_start(a); if (r < 0) { - log_error("Failed to start bus client: %s", strerror(-r)); + log_error_errno(r, "Failed to start bus client: %m"); goto finish; } - r = sd_bus_get_owner_id(a, &server_id); + r = sd_bus_get_bus_id(a, &server_id); if (r < 0) { - log_error("Failed to get server ID: %s", strerror(-r)); + log_error_errno(r, "Failed to get server ID: %m"); goto finish; } + if (a->is_kernel) { + if (!arg_configuration) { + const char *scope; + + r = sd_bus_get_scope(a, &scope); + if (r < 0) { + log_error_errno(r, "Couldn't determine bus scope: %m"); + 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; + } + + if (!arg_configuration) { + r = log_oom(); + goto finish; + } + } + + r = policy_load(&policy_buffer, arg_configuration); + if (r < 0) { + log_error_errno(r, "Failed to load policy: %m"); + goto finish; + } + + policy = &policy_buffer; + /* policy_dump(policy); */ + + 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 = sd_bus_new(&b); if (r < 0) { - log_error("Failed to allocate bus: %s", strerror(-r)); + log_error_errno(r, "Failed to allocate bus: %m"); goto finish; } r = sd_bus_set_fd(b, in_fd, out_fd); if (r < 0) { - log_error("Failed to set fds: %s", strerror(-r)); + log_error_errno(r, "Failed to set fds: %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)); + log_error_errno(r, "Failed to set server mode: %m"); goto finish; } r = sd_bus_negotiate_fds(b, is_unix); if (r < 0) { - log_error("Failed to set FD negotiation: %s", strerror(-r)); + log_error_errno(r, "Failed to set FD negotiation: %m"); + goto finish; + } + + 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) { + log_error_errno(r, "Failed to set credential negotiation: %m"); goto finish; } r = sd_bus_set_anonymous(b, true); if (r < 0) { - log_error("Failed to set anonymous authentication: %s", strerror(-r)); + log_error_errno(r, "Failed to set anonymous authentication: %m"); goto finish; } @@ -1285,13 +1531,13 @@ int main(int argc, char *argv[]) { r = sd_bus_start(b); if (r < 0) { - log_error("Failed to start bus client: %s", strerror(-r)); + log_error_errno(r, "Failed to start bus client: %m"); 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; @@ -1299,7 +1545,7 @@ int main(int argc, char *argv[]) { 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; } @@ -1319,7 +1565,7 @@ int main(int argc, char *argv[]) { 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; } @@ -1340,7 +1586,7 @@ int main(int argc, char *argv[]) { 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; } } @@ -1354,18 +1600,22 @@ int main(int argc, char *argv[]) { 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; @@ -1375,22 +1625,49 @@ int main(int argc, char *argv[]) { 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; } patch_sender(a, m); - k = sd_bus_send(b, m, NULL); - if (k < 0) { - if (k == -ECONNRESET) - r = 0; - else { + if (policy) { + k = process_policy(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 policy: %m"); + goto finish; + } else if (k > 0) { + r = 1; + processed = true; } + } - goto finish; + 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; } } @@ -1398,61 +1675,84 @@ int main(int argc, char *argv[]) { 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; goto finish; } - k = process_hello(a, b, m, &policy, &ucred, &got_hello); + k = process_hello(a, b, m, &got_hello); if (k < 0) { r = k; - log_error("Failed to process HELLO: %s", strerror(-r)); + 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 = process_driver(a, b, m, &policy, &ucred); + if (!processed) { + k = process_driver(a, b, m, policy, &ucred, owned_names); if (k < 0) { r = k; - log_error("Failed to process driver calls: %s", strerror(-r)); + log_error_errno(r, "Failed to process driver calls: %m"); goto finish; + } else if (k > 0) { + processed = true; + r = 1; } - if (k > 0) - r = k; - else { - k = process_policy(a, b, m, &policy, &ucred); - if (k < 0) { - r = k; - log_error("Failed to process policy: %s", strerror(-r)); - goto finish; - } - - k = sd_bus_send(a, m, NULL); - if (k < 0) { - if (k == -ECONNRESET) - r = 0; - else { - r = k; - log_error("Failed to send message: %s", strerror(-r)); + 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; + } } - goto finish; + 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; } } } @@ -1463,31 +1763,31 @@ int main(int argc, char *argv[]) { 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; } @@ -1517,7 +1817,7 @@ int main(int argc, char *argv[]) { r = ppoll(pollfd, 3, ts, NULL); if (r < 0) { - log_error("ppoll() failed: %m"); + log_error_errno(errno, "ppoll() failed: %m"); goto finish; } } @@ -1527,9 +1827,8 @@ finish: "STOPPING=1\n" "STATUS=Shutting down."); - policy_free(&policy); + policy_free(&policy_buffer); strv_free(arg_configuration); - hashmap_free(names_hash); free(arg_address); return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;