X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibsystemd-bus%2Fsd-bus.c;h=df4010265f4aec97ecbadaa0a6553137f834b73d;hb=021a1e78d7621bcd844a9bf22efca88960a8e28b;hp=4bfbd4c651cdf694a997ede987a7f4da57038c7e;hpb=dafb75912a65e72c3989143f79367a652323a69f;p=elogind.git

diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 4bfbd4c65..df4010265 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -29,17 +29,18 @@
 
 #include "util.h"
 #include "macro.h"
+#include "missing.h"
 
 #include "sd-bus.h"
 #include "bus-internal.h"
 #include "bus-message.h"
 #include "bus-type.h"
 
-static int ensure_running(sd_bus *bus);
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
 
 static void bus_free(sd_bus *b) {
         struct filter_callback *f;
+        struct object_callback *c;
         unsigned i;
 
         assert(b);
@@ -52,6 +53,9 @@ static void bus_free(sd_bus *b) {
         free(b->auth_uid);
         free(b->address);
 
+        close_many(b->fds, b->n_fds);
+        free(b->fds);
+
         for (i = 0; i < b->rqueue_size; i++)
                 sd_bus_message_unref(b->rqueue[i]);
         free(b->rqueue);
@@ -68,36 +72,101 @@ static void bus_free(sd_bus *b) {
                 free(f);
         }
 
+        while ((c = hashmap_steal_first(b->object_callbacks))) {
+                free(c->path);
+                free(c);
+        }
+
+        hashmap_free(b->object_callbacks);
+
         free(b);
 }
 
-static sd_bus* bus_new(void) {
+int sd_bus_new(sd_bus **ret) {
         sd_bus *r;
 
+        if (!ret)
+                return -EINVAL;
+
         r = new0(sd_bus, 1);
         if (!r)
-                return NULL;
+                return -ENOMEM;
 
         r->n_ref = 1;
         r->fd = -1;
         r->message_version = 1;
+        r->negotiate_fds = true;
 
         /* We guarantee that wqueue always has space for at least one
          * entry */
         r->wqueue = new(sd_bus_message*, 1);
         if (!r->wqueue) {
                 free(r);
-                return NULL;
+                return -ENOMEM;
         }
 
-        return r;
-};
+        *ret = r;
+        return 0;
+}
+
+int sd_bus_set_address(sd_bus *bus, const char *address) {
+        char *a;
+
+        if (!bus)
+                return -EINVAL;
+        if (bus->state != BUS_UNSET)
+                return -EPERM;
+        if (!address)
+                return -EINVAL;
+
+        a = strdup(address);
+        if (!a)
+                return -ENOMEM;
+
+        free(bus->address);
+        bus->address = a;
+
+        return 0;
+}
+
+int sd_bus_set_fd(sd_bus *bus, int fd) {
+        if (!bus)
+                return -EINVAL;
+        if (bus->state != BUS_UNSET)
+                return -EPERM;
+        if (fd < 0)
+                return -EINVAL;
+
+        bus->fd = fd;
+        return 0;
+}
+
+int sd_bus_set_hello(sd_bus *bus, int b) {
+        if (!bus)
+                return -EINVAL;
+        if (bus->state != BUS_UNSET)
+                return -EPERM;
+
+        bus->send_hello = !!b;
+        return 0;
+}
+
+int sd_bus_set_negotiate_fds(sd_bus *bus, int b) {
+        if (!bus)
+                return -EINVAL;
+        if (bus->state != BUS_UNSET)
+                return -EPERM;
+
+        bus->negotiate_fds = !!b;
+        return 0;
+}
 
 static int hello_callback(sd_bus *bus, int error, sd_bus_message *reply, void *userdata) {
         const char *s;
         int r;
 
         assert(bus);
+        assert(bus->state == BUS_HELLO);
 
         if (error != 0)
                 return -error;
@@ -126,6 +195,9 @@ static int bus_send_hello(sd_bus *bus) {
 
         assert(bus);
 
+        if (!bus->send_hello)
+                return 0;
+
         r = sd_bus_message_new_method_call(
                         bus,
                         "org.freedesktop.DBus",
@@ -140,14 +212,13 @@ static int bus_send_hello(sd_bus *bus) {
         if (r < 0)
                 return r;
 
-        bus->sent_hello = true;
         return r;
 }
 
 static int bus_start_running(sd_bus *bus) {
         assert(bus);
 
-        if (bus->sent_hello) {
+        if (bus->send_hello) {
                 bus->state = BUS_HELLO;
                 return 1;
         }
@@ -428,21 +499,31 @@ static int bus_write_auth(sd_bus *b) {
 }
 
 static int bus_auth_verify(sd_bus *b) {
-        char *e, *f;
+        char *e, *f, *start;
         sd_id128_t peer;
         unsigned i;
         int r;
 
-        /* We expect two response lines: "OK", "AGREE_UNIX_FD", and
-         * that's it */
+        /* We expect two response lines: "OK" and possibly
+         * "AGREE_UNIX_FD" */
 
         e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2);
         if (!e)
                 return 0;
 
-        f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2);
-        if (!f)
-                return 0;
+        if (b->negotiate_fds) {
+                f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2);
+                if (!f)
+                        return 0;
+
+                start = f + 2;
+        } else {
+                f = NULL;
+                start = e + 2;
+        }
+
+        /* Nice! We got all the lines we need. First check the OK
+         * line */
 
         if (e - (char*) b->rbuffer != 3 + 32)
                 return -EPERM;
@@ -468,12 +549,15 @@ static int bus_auth_verify(sd_bus *b) {
 
         b->peer = peer;
 
-        b->can_fds =
-                (f - e == sizeof("\r\nAGREE_UNIX_FD") - 1) &&
-                memcmp(e + 2, "AGREE_UNIX_FD", sizeof("AGREE_UNIX_FD") - 1) == 0;
+        /* And possibly check the second line, too */
+
+        if (f)
+                b->can_fds =
+                        (f - e == sizeof("\r\nAGREE_UNIX_FD") - 1) &&
+                        memcmp(e + 2, "AGREE_UNIX_FD", sizeof("AGREE_UNIX_FD") - 1) == 0;
 
-        b->rbuffer_size -= (f + 2 - (char*) b->rbuffer);
-        memmove(b->rbuffer, f + 2, b->rbuffer_size);
+        b->rbuffer_size -= (start - (char*) b->rbuffer);
+        memmove(b->rbuffer, start, b->rbuffer_size);
 
         r = bus_start_running(b);
         if (r < 0)
@@ -521,6 +605,8 @@ static int bus_read_auth(sd_bus *b) {
         k = recvmsg(b->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
         if (k < 0)
                 return errno == EAGAIN ? 0 : -errno;
+        if (k == 0)
+                return -ECONNRESET;
 
         b->rbuffer_size += k;
 
@@ -531,12 +617,32 @@ static int bus_read_auth(sd_bus *b) {
         return 1;
 }
 
+static int bus_setup_fd(sd_bus *b) {
+        int one;
+
+        assert(b);
+
+        /* Enable SO_PASSCRED + SO_PASSEC. We try this on any socket,
+         * just in case. This is actually irrelavant for */
+        one = 1;
+        setsockopt(b->fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
+        setsockopt(b->fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one));
+
+        /* Increase the buffers to a MB */
+        fd_inc_rcvbuf(b->fd, 1024*1024);
+        fd_inc_sndbuf(b->fd, 1024*1024);
+
+        return 0;
+}
+
 static int bus_start_auth(sd_bus *b) {
         static const char auth_prefix[] = "\0AUTH EXTERNAL ";
-        static const char auth_suffix[] = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n";
+        static const char auth_suffix_with_unix_fd[] = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n";
+        static const char auth_suffix_without_unix_fd[] = "\r\nBEGIN\r\n";
 
         char text[20 + 1]; /* enough space for a 64bit integer plus NUL */
         size_t l;
+        const char *auth_suffix;
 
         assert(b);
 
@@ -550,12 +656,14 @@ static int bus_start_auth(sd_bus *b) {
         if (!b->auth_uid)
                 return -ENOMEM;
 
+        auth_suffix = b->negotiate_fds ? auth_suffix_with_unix_fd : auth_suffix_without_unix_fd;
+
         b->auth_iovec[0].iov_base = (void*) auth_prefix;
         b->auth_iovec[0].iov_len = sizeof(auth_prefix) -1;
         b->auth_iovec[1].iov_base = (void*) b->auth_uid;
         b->auth_iovec[1].iov_len = l * 2;
         b->auth_iovec[2].iov_base = (void*) auth_suffix;
-        b->auth_iovec[2].iov_len = sizeof(auth_suffix) -1;
+        b->auth_iovec[2].iov_len = strlen(auth_suffix);
         b->auth_size = sizeof(auth_prefix) - 1 + l * 2 + sizeof(auth_suffix) - 1;
 
         return bus_write_auth(b);
@@ -579,8 +687,13 @@ static int bus_start_connect(sd_bus *b) {
                 b->fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                 if (b->fd < 0) {
                         b->last_connect_error = errno;
-                        zero(b->sockaddr);
-                        continue;
+                        goto try_again;
+                }
+
+                r = bus_setup_fd(b);
+                if (r < 0) {
+                        b->last_connect_error = errno;
+                        goto try_again;
                 }
 
                 r = connect(b->fd, &b->sockaddr.sa, b->sockaddr_size);
@@ -589,16 +702,64 @@ static int bus_start_connect(sd_bus *b) {
                                 return 1;
 
                         b->last_connect_error = errno;
-                        close_nointr_nofail(b->fd);
-                        b->fd = -1;
-                        zero(b->sockaddr);
-                        continue;
+                        goto try_again;
                 }
 
                 return bus_start_auth(b);
+
+        try_again:
+                zero(b->sockaddr);
+
+                if (b->fd >= 0) {
+                        close_nointr_nofail(b->fd);
+                        b->fd = -1;
+                }
         }
 }
 
+static int bus_start_fd(sd_bus *b) {
+        int r;
+
+        assert(b);
+
+        r = fd_nonblock(b->fd, true);
+        if (r < 0)
+                return r;
+
+        r = fd_cloexec(b->fd, true);
+        if (r < 0)
+                return r;
+
+        r = bus_setup_fd(b);
+        if (r < 0)
+                return r;
+
+        return bus_start_auth(b);
+}
+
+int sd_bus_start(sd_bus *bus) {
+        int r;
+
+        if (!bus)
+                return -EINVAL;
+        if (bus->state != BUS_UNSET)
+                return -EPERM;
+
+        bus->state = BUS_OPENING;
+
+        if (bus->fd >= 0)
+                r = bus_start_fd(bus);
+        else if (bus->address)
+                r = bus_start_connect(bus);
+        else
+                return -EINVAL;
+
+        if (r < 0)
+                return r;
+
+        return bus_send_hello(bus);
+}
+
 int sd_bus_open_system(sd_bus **ret) {
         const char *e;
         sd_bus *b;
@@ -607,35 +768,33 @@ int sd_bus_open_system(sd_bus **ret) {
         if (!ret)
                 return -EINVAL;
 
+        r = sd_bus_new(&b);
+        if (r < 0)
+                return r;
+
         e = getenv("DBUS_SYSTEM_BUS_ADDRESS");
         if (e) {
-                r = sd_bus_open_address(e, &b);
+                r = sd_bus_set_address(b, e);
                 if (r < 0)
-                        return r;
+                        goto fail;
         } else {
-                b = bus_new();
-                if (!b)
-                        return -ENOMEM;
-
                 b->sockaddr.un.sun_family = AF_UNIX;
                 strncpy(b->sockaddr.un.sun_path, "/run/dbus/system_bus_socket", sizeof(b->sockaddr.un.sun_path));
                 b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + sizeof("/run/dbus/system_bus_socket") - 1;
-
-                r = bus_start_connect(b);
-                if (r < 0) {
-                        bus_free(b);
-                        return r;
-                }
         }
 
-        r = bus_send_hello(b);
-        if (r < 0) {
-                sd_bus_unref(b);
-                return r;
-        }
+        b->send_hello = true;
+
+        r = sd_bus_start(b);
+        if (r < 0)
+                goto fail;
 
         *ret = b;
         return 0;
+
+fail:
+        bus_free(b);
+        return r;
 }
 
 int sd_bus_open_user(sd_bus **ret) {
@@ -647,99 +806,45 @@ int sd_bus_open_user(sd_bus **ret) {
         if (!ret)
                 return -EINVAL;
 
+        r = sd_bus_new(&b);
+        if (r < 0)
+                return r;
+
         e = getenv("DBUS_SESSION_BUS_ADDRESS");
         if (e) {
-                r = sd_bus_open_address(e, &b);
+                r = sd_bus_set_address(b, e);
                 if (r < 0)
-                        return r;
+                        goto fail;
         } else {
                 e = getenv("XDG_RUNTIME_DIR");
-                if (!e)
-                        return -ENOENT;
+                if (!e) {
+                        r = -ENOENT;
+                        goto fail;
+                }
 
                 l = strlen(e);
-                if (l + 4 > sizeof(b->sockaddr.un.sun_path))
-                        return -E2BIG;
-
-                b = bus_new();
-                if (!b)
-                        return -ENOMEM;
+                if (l + 4 > sizeof(b->sockaddr.un.sun_path)) {
+                        r = -E2BIG;
+                        goto fail;
+                }
 
                 b->sockaddr.un.sun_family = AF_UNIX;
                 memcpy(mempcpy(b->sockaddr.un.sun_path, e, l), "/bus", 4);
                 b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + l + 4;
-
-                r = bus_start_connect(b);
-                if (r < 0) {
-                        bus_free(b);
-                        return r;
-                }
-        }
-
-        r = bus_send_hello(b);
-        if (r < 0) {
-                sd_bus_unref(b);
-                return r;
         }
 
-        *ret = b;
-        return 0;
-}
-
-int sd_bus_open_address(const char *address, sd_bus **ret) {
-        sd_bus *b;
-        int r;
-
-        if (!address)
-                return -EINVAL;
-        if (!ret)
-                return -EINVAL;
-
-        b = bus_new();
-        if (!b)
-                return -ENOMEM;
-
-        b->address = strdup(address);
-        if (!b->address) {
-                bus_free(b);
-                return -ENOMEM;
-        }
+        b->send_hello = true;
 
-        r = bus_start_connect(b);
-        if (r < 0) {
-                bus_free(b);
-                return r;
-        }
+        r = sd_bus_start(b);
+        if (r < 0)
+                goto fail;
 
         *ret = b;
         return 0;
-}
-
-int sd_bus_open_fd(int fd, sd_bus **ret) {
-        sd_bus *b;
-        int r;
 
-        if (fd < 0)
-                return -EINVAL;
-        if (!ret)
-                return -EINVAL;
-
-        b = bus_new();
-        if (!b)
-                return -ENOMEM;
-
-        b->fd = fd;
-        fd_nonblock(b->fd, true);
-        fd_cloexec(b->fd, true);
-
-        r = bus_start_auth(b);
-        if (r < 0) {
-                bus_free(b);
-                return r;
-        }
-
-        *ret = b;
-        return 0;
+fail:
+        bus_free(b);
+        return r;
 }
 
 void sd_bus_close(sd_bus *bus) {
@@ -779,7 +884,7 @@ int sd_bus_is_open(sd_bus *bus) {
         if (!bus)
                 return -EINVAL;
 
-        return bus->fd >= 0;
+        return bus->state != BUS_UNSET && bus->fd >= 0;
 }
 
 int sd_bus_can_send(sd_bus *bus, char type) {
@@ -787,9 +892,14 @@ int sd_bus_can_send(sd_bus *bus, char type) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->fd < 0)
+                return -ENOTCONN;
 
         if (type == SD_BUS_TYPE_UNIX_FD) {
-                r = ensure_running(bus);
+                if (!bus->negotiate_fds)
+                        return 0;
+
+                r = bus_ensure_running(bus);
                 if (r < 0)
                         return r;
 
@@ -807,7 +917,7 @@ int sd_bus_get_peer(sd_bus *bus, sd_id128_t *peer) {
         if (!peer)
                 return -EINVAL;
 
-        r = ensure_running(bus);
+        r = bus_ensure_running(bus);
         if (r < 0)
                 return r;
 
@@ -841,6 +951,18 @@ static int message_write(sd_bus *bus, sd_bus_message *m, size_t *idx) {
 
         if (*idx >= m->size)
                 return 0;
+        zero(mh);
+
+        if (m->n_fds > 0) {
+                struct cmsghdr *control;
+                control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds));
+
+                mh.msg_control = control;
+                control->cmsg_level = SOL_SOCKET;
+                control->cmsg_type = SCM_RIGHTS;
+                mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds);
+                memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds);
+        }
 
         n = m->n_iovec * sizeof(struct iovec);
         iov = alloca(n);
@@ -849,7 +971,6 @@ static int message_write(sd_bus *bus, sd_bus_message *m, size_t *idx) {
         j = 0;
         iovec_advance(iov, &j, *idx);
 
-        zero(mh);
         mh.msg_iov = iov;
         mh.msg_iovlen = m->n_iovec;
 
@@ -915,7 +1036,7 @@ static int message_read_need(sd_bus *bus, size_t *need) {
 
 static int message_make(sd_bus *bus, size_t size, sd_bus_message **m) {
         sd_bus_message *t;
-        void *b = NULL;
+        void *b;
         int r;
 
         assert(bus);
@@ -924,14 +1045,18 @@ static int message_make(sd_bus *bus, size_t size, sd_bus_message **m) {
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
         if (bus->rbuffer_size > size) {
-                b = memdup((const uint8_t*) bus->rbuffer + size, bus->rbuffer_size - size);
-                if (!b) {
-                        free(t);
+                b = memdup((const uint8_t*) bus->rbuffer + size,
+                           bus->rbuffer_size - size);
+                if (!b)
                         return -ENOMEM;
-                }
-        }
+        } else
+                b = NULL;
 
-        r = bus_message_from_malloc(bus->rbuffer, size, &t);
+        r = bus_message_from_malloc(bus->rbuffer, size,
+                                    bus->fds, bus->n_fds,
+                                    bus->ucred_valid ? &bus->ucred : NULL,
+                                    bus->label[0] ? bus->label : NULL,
+                                    &t);
         if (r < 0) {
                 free(b);
                 return r;
@@ -940,6 +1065,9 @@ static int message_make(sd_bus *bus, size_t size, sd_bus_message **m) {
         bus->rbuffer = b;
         bus->rbuffer_size -= size;
 
+        bus->fds = NULL;
+        bus->n_fds = 0;
+
         *m = t;
         return 1;
 }
@@ -951,6 +1079,13 @@ static int message_read(sd_bus *bus, sd_bus_message **m) {
         size_t need;
         int r;
         void *b;
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) +
+                            CMSG_SPACE(sizeof(struct ucred)) +
+                            CMSG_SPACE(NAME_MAX)]; /*selinux label */
+        } control;
+        struct cmsghdr *cmsg;
 
         assert(bus);
         assert(m);
@@ -976,13 +1111,50 @@ static int message_read(sd_bus *bus, sd_bus_message **m) {
         zero(mh);
         mh.msg_iov = &iov;
         mh.msg_iovlen = 1;
+        mh.msg_control = &control;
+        mh.msg_controllen = sizeof(control);
 
-        k = recvmsg(bus->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
+        k = recvmsg(bus->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
         if (k < 0)
                 return errno == EAGAIN ? 0 : -errno;
+        if (k == 0)
+                return -ECONNRESET;
 
         bus->rbuffer_size += k;
 
+        for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
+                if (cmsg->cmsg_level == SOL_SOCKET &&
+                    cmsg->cmsg_type == SCM_RIGHTS) {
+                        int n, *f;
+
+                        n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
+
+                        f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n));
+                        if (!f) {
+                                close_many((int*) CMSG_DATA(cmsg), n);
+                                return -ENOMEM;
+                        }
+
+                        memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int));
+                        bus->fds = f;
+                        bus->n_fds += n;
+                } else if (cmsg->cmsg_level == SOL_SOCKET &&
+                    cmsg->cmsg_type == SCM_CREDENTIALS &&
+                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
+
+                        memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));
+                        bus->ucred_valid = true;
+
+                } else if (cmsg->cmsg_level == SOL_SOCKET &&
+                         cmsg->cmsg_type == SCM_SECURITY) {
+
+                        size_t l;
+                        l = cmsg->cmsg_len - CMSG_LEN(0);
+                        memcpy(&bus->label, CMSG_DATA(cmsg), l);
+                        bus->label[l] = 0;
+                }
+        }
+
         r = message_read_need(bus, &need);
         if (r < 0)
                 return r;
@@ -1035,7 +1207,7 @@ static int dispatch_wqueue(sd_bus *bus) {
 }
 
 static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
-        sd_bus_message *z;
+        sd_bus_message *z = NULL;
         int r, ret = 0;
 
         assert(bus);
@@ -1076,11 +1248,21 @@ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
         if (!m)
                 return -EINVAL;
 
+        if (m->n_fds > 0) {
+                r = sd_bus_can_send(bus, SD_BUS_TYPE_UNIX_FD);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -ENOTSUP;
+        }
+
         /* If the serial number isn't kept, then we know that no reply
          * is expected */
         if (!serial && !m->sealed)
@@ -1175,6 +1357,8 @@ int sd_bus_send_with_reply(
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
         if (!m)
@@ -1252,11 +1436,16 @@ int sd_bus_send_with_reply_cancel(sd_bus *bus, uint64_t serial) {
         return 1;
 }
 
-static int ensure_running(sd_bus *bus) {
+int bus_ensure_running(sd_bus *bus) {
         int r;
 
         assert(bus);
 
+        if (bus->fd < 0)
+                return -ENOTCONN;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
+
         if (bus->state == BUS_RUNNING)
                 return 1;
 
@@ -1291,6 +1480,8 @@ int sd_bus_send_with_reply_and_block(
                 return -EINVAL;
         if (bus->fd < 0)
                 return -ENOTCONN;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (!m)
                 return -EINVAL;
         if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
@@ -1300,7 +1491,7 @@ int sd_bus_send_with_reply_and_block(
         if (bus_error_is_dirty(error))
                 return -EINVAL;
 
-        r = ensure_running(bus);
+        r = bus_ensure_running(bus);
         if (r < 0)
                 return r;
 
@@ -1409,6 +1600,8 @@ int sd_bus_get_events(sd_bus *bus) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
 
@@ -1438,6 +1631,8 @@ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
                 return -EINVAL;
         if (!timeout_usec)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
 
@@ -1458,7 +1653,6 @@ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
 }
 
 static int process_timeout(sd_bus *bus) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         struct reply_callback *c;
         usec_t n;
         int r;
@@ -1482,6 +1676,43 @@ static int process_timeout(sd_bus *bus) {
         return r < 0 ? r : 1;
 }
 
+static int process_reply(sd_bus *bus, sd_bus_message *m) {
+        struct reply_callback *c;
+        int r;
+
+        assert(bus);
+        assert(m);
+
+        if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_RETURN &&
+            m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_ERROR)
+                return 0;
+
+        c = hashmap_remove(bus->reply_callbacks, &m->reply_serial);
+        if (!c)
+                return 0;
+
+        if (c->timeout != 0)
+                prioq_remove(bus->reply_callbacks_prioq, c, &c->prioq_idx);
+
+        r = c->callback(bus, 0, m, c->userdata);
+        free(c);
+
+        return r;
+}
+
+static int process_filter(sd_bus *bus, sd_bus_message *m) {
+        struct filter_callback *l;
+        int r;
+
+        LIST_FOREACH(callbacks, l, bus->filter_callbacks) {
+                r = l->callback(bus, 0, m, l->userdata);
+                if (r != 0)
+                        return r;
+        }
+
+        return 0;
+}
+
 static int process_builtin(sd_bus *bus, sd_bus_message *m) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         int r;
@@ -1533,36 +1764,90 @@ static int process_builtin(sd_bus *bus, sd_bus_message *m) {
         return 1;
 }
 
-static int process_message(sd_bus *bus, sd_bus_message *m) {
-        struct filter_callback *l;
+static int process_object(sd_bus *bus, sd_bus_message *m) {
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_INIT;
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        struct object_callback *c;
+        char *p;
         int r;
+        bool found = false;
 
         assert(bus);
         assert(m);
 
-        if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_RETURN || m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_ERROR) {
-                struct reply_callback *c;
+        if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
+                return 0;
 
-                c = hashmap_remove(bus->reply_callbacks, &m->reply_serial);
-                if (c) {
-                        if (c->timeout != 0)
-                                prioq_remove(bus->reply_callbacks_prioq, c, &c->prioq_idx);
+        if (hashmap_isempty(bus->object_callbacks))
+                return 0;
 
-                        r = c->callback(bus, 0, m, c->userdata);
-                        free(c);
+        c = hashmap_get(bus->object_callbacks, m->path);
+        if (c) {
+                r = c->callback(bus, 0, m, c->userdata);
+                if (r != 0)
+                        return r;
 
+                found = true;
+        }
+
+        /* Look for fallback prefixes */
+        p = strdupa(m->path);
+        for (;;) {
+                char *e;
+
+                e = strrchr(p, '/');
+                if (e == p || !e)
+                        break;
+
+                *e = 0;
+
+                c = hashmap_get(bus->object_callbacks, p);
+                if (c && c->is_fallback) {
+                        r = c->callback(bus, 0, m, c->userdata);
                         if (r != 0)
                                 return r;
+
+                        found = true;
                 }
         }
 
-        LIST_FOREACH(callbacks, l, bus->filter_callbacks) {
-                r = l->callback(bus, 0, m, l->userdata);
-                if (r != 0)
-                        return r;
-        }
+        if (!found)
+                return 0;
+
+        sd_bus_error_set(&error,
+                         "org.freedesktop.DBus.Error.UnknownMethod",
+                         "Unknown method '%s' or interface '%s'.", m->member, m->interface);
+
+        r = sd_bus_message_new_method_error(bus, m, &error, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
 
-        return process_builtin(bus, m);
+        return 1;
+}
+
+static int process_message(sd_bus *bus, sd_bus_message *m) {
+        int r;
+
+        assert(bus);
+        assert(m);
+
+        r = process_reply(bus, m);
+        if (r != 0)
+                return r;
+
+        r = process_filter(bus, m);
+        if (r != 0)
+                return r;
+
+        r = process_builtin(bus, m);
+        if (r != 0)
+                return r;
+
+        return process_object(bus, m);
 }
 
 int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
@@ -1575,6 +1860,8 @@ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
 
@@ -1731,6 +2018,8 @@ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
         if (bus->rqueue_size > 0)
@@ -1744,10 +2033,12 @@ int sd_bus_flush(sd_bus *bus) {
 
         if (!bus)
                 return -EINVAL;
+        if (bus->state == BUS_UNSET)
+                return -ENOTCONN;
         if (bus->fd < 0)
                 return -ENOTCONN;
 
-        r = ensure_running(bus);
+        r = bus_ensure_running(bus);
         if (r < 0)
                 return r;
 
@@ -1804,3 +2095,95 @@ int sd_bus_remove_filter(sd_bus *bus, sd_message_handler_t callback, void *userd
 
         return 0;
 }
+
+static int bus_add_object(
+                sd_bus *bus,
+                bool fallback,
+                const char *path,
+                sd_message_handler_t callback,
+                void *userdata) {
+
+        struct object_callback *c;
+        int r;
+
+        if (!bus)
+                return -EINVAL;
+        if (!path)
+                return -EINVAL;
+        if (!callback)
+                return -EINVAL;
+
+        r = hashmap_ensure_allocated(&bus->object_callbacks, string_hash_func, string_compare_func);
+        if (r < 0)
+                return r;
+
+        c = new(struct object_callback, 1);
+        if (!c)
+                return -ENOMEM;
+
+        c->path = strdup(path);
+        if (!path) {
+                free(c);
+                return -ENOMEM;
+        }
+
+        c->callback = callback;
+        c->userdata = userdata;
+        c->is_fallback = fallback;
+
+        r = hashmap_put(bus->object_callbacks, c->path, c);
+        if (r < 0) {
+                free(c->path);
+                free(c);
+                return r;
+        }
+
+        return 0;
+}
+
+static int bus_remove_object(
+                sd_bus *bus,
+                bool fallback,
+                const char *path,
+                sd_message_handler_t callback,
+                void *userdata) {
+
+        struct object_callback *c;
+
+        if (!bus)
+                return -EINVAL;
+        if (!path)
+                return -EINVAL;
+        if (!callback)
+                return -EINVAL;
+
+        c = hashmap_get(bus->object_callbacks, path);
+        if (!c)
+                return 0;
+
+        if (c->callback != callback || c->userdata != userdata || c->is_fallback != fallback)
+                return 0;
+
+        assert_se(c == hashmap_remove(bus->object_callbacks, c->path));
+
+        free(c->path);
+        free(c);
+
+        return 1;
+}
+
+int sd_bus_add_object(sd_bus *bus, const char *path, sd_message_handler_t callback, void *userdata) {
+        return bus_add_object(bus, false, path, callback, userdata);
+}
+
+int sd_bus_remove_object(sd_bus *bus, const char *path, sd_message_handler_t callback, void *userdata) {
+        return bus_remove_object(bus, false, path, callback, userdata);
+}
+
+int sd_bus_add_fallback(sd_bus *bus, const char *prefix, sd_message_handler_t callback, void *userdata) {
+        return bus_add_object(bus, true, prefix, callback, userdata);
+}
+
+int sd_bus_remove_fallback(sd_bus *bus, const char *prefix, sd_message_handler_t callback, void *userdata) {
+        return bus_remove_object(bus, true, prefix, callback, userdata);
+}