bus: basic implementation of kdbus client side

9 files changed, 959 insertions, 41 deletions

diff --git a/Makefile.am b/Makefile.am
index ec81f53ab7..ae58c16969 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1700,6 +1700,8 @@ libsystemd_bus_la_SOURCES = \
 	src/libsystemd-bus/bus-internal.h \
 	src/libsystemd-bus/bus-socket.c \
 	src/libsystemd-bus/bus-socket.h \
+	src/libsystemd-bus/bus-kernel.c \
+	src/libsystemd-bus/bus-kernel.h \
 	src/libsystemd-bus/bus-message.c \
 	src/libsystemd-bus/bus-message.h \
 	src/libsystemd-bus/bus-signature.c \
@@ -4105,6 +4107,10 @@ hwdb-update:
 	        http://standards.ieee.org/develop/regauth/iab/iab.txt && \
 	./ids-update.pl )
 
+kdbus-update:
+	( cd $(top_srcdir)/src/libsystemd-bus/ && \
+	wget -N https://d-bus.googlecode.com/git/kdbus.h )
+
 upload: all distcheck
 	cp -v systemd-$(VERSION).tar.xz /home/lennart/git.fedora/systemd/
 	scp systemd-$(VERSION).tar.xz fdo:/srv/www.freedesktop.org/www/software/systemd/
diff --git a/src/libsystemd-bus/bus-internal.h b/src/libsystemd-bus/bus-internal.h
index 6ff3163cfd..7cca9998bb 100644
--- a/src/libsystemd-bus/bus-internal.h
+++ b/src/libsystemd-bus/bus-internal.h
@@ -81,6 +81,7 @@ struct sd_bus {
         int input_fd, output_fd;
         int message_version;
 
+        bool is_kernel:1;
         bool negotiate_fds:1;
         bool can_fds:1;
         bool bus_client:1;
@@ -122,6 +123,8 @@ struct sd_bus {
         } sockaddr;
         socklen_t sockaddr_size;
 
+        char *kernel;
+
         sd_id128_t server_id;
 
         char *address;
diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
new file mode 100644
index 0000000000..c10fcc54df
--- /dev/null
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -0,0 +1,388 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <fcntl.h>
+
+#include "util.h"
+
+#include "bus-internal.h"
+#include "bus-message.h"
+#include "bus-kernel.h"
+
+#define KDBUS_MSG_FOREACH_DATA(d, k)                                    \
+        for ((d) = (k)->data;                                           \
+             (uint8_t*) (d) < (uint8_t*) (k) + (k)->size;               \
+             (d) = (struct kdbus_msg_data*) ((uint8_t*) (d) + ALIGN8((d)->size)))
+
+
+
+static int parse_unique_name(const char *s, uint64_t *id) {
+        int r;
+
+        assert(s);
+        assert(id);
+
+        if (!startswith(s, ":1."))
+                return 0;
+
+        r = safe_atou64(s + 3, id);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static void append_payload_vec(struct kdbus_msg_data **d, const void *p, size_t sz) {
+        assert(d);
+        assert(p);
+        assert(sz > 0);
+
+        (*d)->size = offsetof(struct kdbus_msg_data, vec) + sizeof(struct kdbus_vec);
+        (*d)->type = KDBUS_MSG_PAYLOAD_VEC;
+        (*d)->vec.address = (uint64_t) p;
+        (*d)->vec.size = sz;
+
+        *d = (struct kdbus_msg_data*) ((uint8_t*) *d + ALIGN8((*d)->size));
+}
+
+static void append_destination(struct kdbus_msg_data **d, const char *s, size_t length) {
+        assert(d);
+        assert(d);
+
+        (*d)->size = offsetof(struct kdbus_msg_data, data) + length + 1;
+        (*d)->type = KDBUS_MSG_DST_NAME;
+        memcpy((*d)->data, s, length + 1);
+
+        *d = (struct kdbus_msg_data*) ((uint8_t*) *d + ALIGN8((*d)->size));
+}
+
+static int bus_message_setup_kmsg(sd_bus_message *m) {
+        struct kdbus_msg_data *d;
+        bool well_known;
+        uint64_t unique;
+        size_t sz, dl;
+        int r;
+
+        assert(m);
+        assert(m->sealed);
+        assert(!m->kdbus);
+
+        if (m->destination) {
+                r = parse_unique_name(m->destination, &unique);
+                if (r < 0)
+                        return r;
+
+                well_known = r == 0;
+        } else
+                well_known = false;
+
+        sz = offsetof(struct kdbus_msg, data);
+
+        /* Add in fixed header, fields header, fields header padding and payload */
+        sz += 4 * ALIGN8(offsetof(struct kdbus_msg_data, vec) + sizeof(struct kdbus_vec));
+
+        /* Add in well-known destination header */
+        if (well_known) {
+                dl = strlen(m->destination);
+                sz += ALIGN8(offsetof(struct kdbus_msg, data) + dl + 1);
+        }
+
+        m->kdbus = malloc0(sz);
+        if (!m->kdbus)
+                return -ENOMEM;
+
+        m->kdbus->flags =
+                ((m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
+                ((m->header->flags & SD_BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);
+        m->kdbus->dst_id =
+                well_known ? 0 :
+                m->destination ? unique : (uint64_t) -1;
+        m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS1;
+        m->kdbus->cookie = m->header->serial;
+
+        m->kdbus->timeout_ns = m->timeout * NSEC_PER_USEC;
+
+        d = m->kdbus->data;
+
+        if (well_known)
+                append_destination(&d, m->destination, dl);
+
+        append_payload_vec(&d, m->header, sizeof(*m->header));
+
+        if (m->fields) {
+                append_payload_vec(&d, m->fields, m->header->fields_size);
+
+                if (m->header->fields_size % 8 != 0) {
+                        static const uint8_t padding[7] = {};
+
+                        append_payload_vec(&d, padding, 8 - (m->header->fields_size % 8));
+                }
+        }
+
+        if (m->body)
+                append_payload_vec(&d, m->body, m->header->body_size);
+
+        m->kdbus->size = (uint8_t*) m - (uint8_t*) m->kdbus;
+        assert(m->kdbus->size <= sz);
+
+        return 0;
+}
+
+int bus_kernel_take_fd(sd_bus *b) {
+        struct kdbus_cmd_hello hello = {};
+        int r;
+
+        assert(b);
+
+        r = ioctl(b->input_fd, KDBUS_CMD_HELLO, &hello);
+        if (r < 0)
+                return -errno;
+
+        b->is_kernel = true;
+
+        r = bus_start_running(b);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+int bus_kernel_connect(sd_bus *b) {
+        assert(b);
+        assert(b->input_fd < 0);
+        assert(b->output_fd < 0);
+        assert(b->kernel);
+
+        b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (b->input_fd)
+                return -errno;
+
+        b->output_fd = b->input_fd;
+
+        return bus_kernel_take_fd(b);
+}
+
+int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(bus->state == BUS_RUNNING);
+
+        r = bus_message_setup_kmsg(m);
+        if (r < 0)
+                return r;
+
+        r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
+        if (r < 0)
+                return errno == EAGAIN ? 0 : -errno;
+
+        return 0;
+}
+
+static void close_kdbus_msg(struct kdbus_msg *k) {
+        struct kdbus_msg_data *d;
+
+        KDBUS_MSG_FOREACH_DATA(d, k) {
+
+                if (d->type != KDBUS_MSG_UNIX_FDS)
+                        continue;
+
+                close_many(d->fds, (d->size - offsetof(struct kdbus_msg_data, fds)) / sizeof(int));
+        }
+}
+
+static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_message **ret) {
+        sd_bus_message *m = NULL;
+        struct kdbus_msg_data *d;
+        unsigned n_payload = 0, n_fds = 0;
+        _cleanup_free_ int *fds = NULL;
+        struct bus_header *h = NULL;
+        size_t total, n_bytes = 0, idx = 0;
+        int r;
+
+        assert(bus);
+        assert(k);
+        assert(ret);
+
+        if (k->payload_type != KDBUS_PAYLOAD_DBUS1)
+                return 0;
+
+        KDBUS_MSG_FOREACH_DATA(d, k) {
+                size_t l;
+
+                l = d->size - offsetof(struct kdbus_msg_data, data);
+
+                if (d->type == KDBUS_MSG_PAYLOAD) {
+
+                        if (!h) {
+                                if (l < sizeof(struct bus_header))
+                                        return -EBADMSG;
+
+                                h = (struct bus_header*) d->data;
+                        }
+
+                        n_payload++;
+                        n_bytes += l;
+
+                } else if (d->type == KDBUS_MSG_UNIX_FDS) {
+                        int *f;
+                        unsigned j;
+
+                        j = l / sizeof(int);
+                        f = realloc(fds, sizeof(int) * (n_fds + j));
+                        if (!f)
+                                return -ENOMEM;
+
+                        fds = f;
+                        memcpy(fds + n_fds, d->fds, j);
+                        n_fds += j;
+                }
+        }
+
+        if (!h)
+                return -EBADMSG;
+
+        r = bus_header_size(h, &total);
+        if (r < 0)
+                return r;
+
+        if (n_bytes != total)
+                return -EBADMSG;
+
+        r = bus_message_from_header(h, sizeof(struct bus_header), fds, n_fds, NULL, NULL, 0, &m);
+        if (r < 0)
+                return r;
+
+        KDBUS_MSG_FOREACH_DATA(d, k) {
+                size_t l;
+
+                if (d->type != KDBUS_MSG_PAYLOAD)
+                        continue;
+
+                l = d->size - offsetof(struct kdbus_msg_data, data);
+
+                if (idx == sizeof(struct bus_header) &&
+                    l == BUS_MESSAGE_FIELDS_SIZE(m))
+                        m->fields = d->data;
+                else if (idx == sizeof(struct bus_header) + ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m)) &&
+                         l == BUS_MESSAGE_BODY_SIZE(m))
+                        m->body = d->data;
+                else {
+                        sd_bus_message_unref(m);
+                        return -EBADMSG;
+                }
+
+                idx += l;
+        }
+
+        r = bus_message_parse_fields(m);
+        if (r < 0) {
+                sd_bus_message_unref(m);
+                return r;
+        }
+
+        /* We take possession of the kmsg struct now */
+        m->kdbus = k;
+        m->free_kdbus = true;
+        m->free_fds = true;
+
+        fds = NULL;
+
+        *ret = m;
+        return 1;
+}
+
+int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
+        struct kdbus_msg *k;
+        size_t sz = 128;
+        int r;
+
+        assert(bus);
+        assert(m);
+
+        for (;;) {
+                void *q;
+
+                q = realloc(bus->rbuffer, sz);
+                if (!q)
+                        return -errno;
+
+                k = bus->rbuffer = q;
+                k->size = sz;
+
+                r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, bus->rbuffer);
+                if (r >= 0)
+                        break;
+
+                if (errno == EAGAIN)
+                        return 0;
+
+                if (errno != -EMSGSIZE)
+                        return -errno;
+
+                sz *= 2;
+        }
+
+        r = bus_kernel_make_message(bus, k, m);
+        if (r > 0)
+                bus->rbuffer = NULL;
+        else
+                close_kdbus_msg(k);
+
+        return r;
+}
+
+int bus_kernel_create(const char *name, char **s) {
+        struct kdbus_cmd_fname *fname;
+        size_t l;
+        int fd;
+        char *p;
+
+        assert(name);
+        assert(s);
+
+        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        l = strlen(name);
+        fname = alloca(offsetof(struct kdbus_cmd_fname, name) + DECIMAL_STR_MAX(uid_t) + 1 + l + 1);
+        sprintf(fname->name, "%lu-%s", (unsigned long) getuid(), name);
+        fname->size = offsetof(struct kdbus_cmd_fname, name) + strlen(fname->name) + 1;
+        fname->kernel_flags = KDBUS_CMD_FNAME_ACCESS_WORLD;
+        fname->user_flags = 0;
+
+        p = strjoin("/dev/kdbus/", fname->name, "/bus", NULL);
+        if (!p)
+                return -ENOMEM;
+
+        if (ioctl(fd, KDBUS_CMD_BUS_MAKE, &fname) < 0) {
+                close_nointr_nofail(fd);
+                free(p);
+                return -errno;
+        }
+
+        if (s)
+                *s = p;
+
+        return fd;
+}
diff --git a/src/libsystemd-bus/bus-kernel.h b/src/libsystemd-bus/bus-kernel.h
new file mode 100644
index 0000000000..ac746afe03
--- /dev/null
+++ b/src/libsystemd-bus/bus-kernel.h
@@ -0,0 +1,32 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-bus.h"
+
+int bus_kernel_connect(sd_bus *b);
+int bus_kernel_take_fd(sd_bus *b);
+
+int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m);
+int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m);
+
+int bus_kernel_create(const char *name, char **s);
diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index fb4718085b..eeb1d823e8 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -25,6 +25,7 @@
 #include "util.h"
 #include "utf8.h"
 #include "strv.h"
+#include "time-util.h"
 
 #include "sd-bus.h"
 #include "bus-message.h"
@@ -32,7 +33,6 @@
 #include "bus-type.h"
 #include "bus-signature.h"
 
-static int message_parse_fields(sd_bus_message *m);
 static int message_append_basic(sd_bus_message *m, char type, const void *p, const void **stored);
 
 static void reset_containers(sd_bus_message *m) {
@@ -62,6 +62,9 @@ static void message_free(sd_bus_message *m) {
         if (m->free_body)
                 free(m->body);
 
+        if (m->free_kdbus)
+                free(m->kdbus);
+
         if (m->free_fds) {
                 close_many(m->fds, m->n_fds);
                 free(m->fds);
@@ -225,19 +228,19 @@ static int message_append_field_uint32(sd_bus_message *m, uint8_t h, uint32_t x)
         return 0;
 }
 
-int bus_message_from_malloc(
+int bus_message_from_header(
                 void *buffer,
                 size_t length,
                 int *fds,
                 unsigned n_fds,
                 const struct ucred *ucred,
                 const char *label,
+                size_t extra,
                 sd_bus_message **ret) {
 
         sd_bus_message *m;
         struct bus_header *h;
-        size_t total, fs, bs, label_sz, a;
-        int r;
+        size_t a, label_sz;
 
         assert(buffer || length <= 0);
         assert(fds || n_fds <= 0);
@@ -256,24 +259,16 @@ int bus_message_from_malloc(
         if (h->type == _SD_BUS_MESSAGE_TYPE_INVALID)
                 return -EBADMSG;
 
-        if (h->endian == SD_BUS_NATIVE_ENDIAN) {
-                fs = h->fields_size;
-                bs = h->body_size;
-        } else if (h->endian == SD_BUS_REVERSE_ENDIAN) {
-                fs = bswap_32(h->fields_size);
-                bs = bswap_32(h->body_size);
-        } else
+        if (h->endian != SD_BUS_LITTLE_ENDIAN &&
+            h->endian != SD_BUS_BIG_ENDIAN)
                 return -EBADMSG;
 
-        total = sizeof(struct bus_header) + ALIGN8(fs) + bs;
-        if (length != total)
-                return -EBADMSG;
+        a = ALIGN(sizeof(sd_bus_message)) + ALIGN(extra);
 
         if (label) {
                 label_sz = strlen(label);
-                a = ALIGN(sizeof(sd_bus_message)) + label_sz + 1;
-        } else
-                a = sizeof(sd_bus_message);
+                a += label_sz + 1;
+        }
 
         m = malloc0(a);
         if (!m)
@@ -282,8 +277,6 @@ int bus_message_from_malloc(
         m->n_ref = 1;
         m->sealed = true;
         m->header = h;
-        m->fields = (uint8_t*) buffer + sizeof(struct bus_header);
-        m->body = (uint8_t*) buffer + sizeof(struct bus_header) + ALIGN8(fs);
         m->fds = fds;
         m->n_fds = n_fds;
 
@@ -295,15 +288,43 @@ int bus_message_from_malloc(
         }
 
         if (label) {
-                m->label = (char*) m + ALIGN(sizeof(sd_bus_message));
+                m->label = (char*) m + ALIGN(sizeof(sd_bus_message)) + ALIGN(extra);
                 memcpy(m->label, label, label_sz + 1);
         }
 
+        *ret = m;
+        return 0;
+}
+
+int bus_message_from_malloc(
+                void *buffer,
+                size_t length,
+                int *fds,
+                unsigned n_fds,
+                const struct ucred *ucred,
+                const char *label,
+                sd_bus_message **ret) {
+
+        sd_bus_message *m;
+        int r;
+
+        r = bus_message_from_header(buffer, length, fds, n_fds, ucred, label, 0, &m);
+        if (r < 0)
+                return r;
+
+        if (length != BUS_MESSAGE_SIZE(m)) {
+                r = -EBADMSG;
+                goto fail;
+        }
+
+        m->fields = (uint8_t*) buffer + sizeof(struct bus_header);
+        m->body = (uint8_t*) buffer + sizeof(struct bus_header) + ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m));
+
         m->n_iovec = 1;
         m->iovec[0].iov_base = buffer;
         m->iovec[0].iov_len = length;
 
-        r = message_parse_fields(m);
+        r = bus_message_parse_fields(m);
         if (r < 0)
                 goto fail;
 
@@ -2600,7 +2621,7 @@ static int message_skip_fields(
         }
 }
 
-static int message_parse_fields(sd_bus_message *m) {
+int bus_message_parse_fields(sd_bus_message *m) {
         size_t ri;
         int r;
         uint32_t unix_fds = 0;
@@ -3041,7 +3062,7 @@ int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz) {
         assert(buffer);
         assert(sz);
 
-        total = bus_message_size(m);
+        total = BUS_MESSAGE_SIZE(m);
 
         p = malloc(total);
         if (!p)
@@ -3133,12 +3154,21 @@ const char* bus_message_get_arg(sd_bus_message *m, unsigned i) {
         return t;
 }
 
-size_t bus_message_size(sd_bus_message *m) {
-        assert(m);
-        assert(m->sealed);
+int bus_header_size(struct bus_header *h, size_t *sum) {
+        size_t fs, bs;
+
+        assert(h);
+        assert(sum);
+
+        if (h->endian == SD_BUS_NATIVE_ENDIAN) {
+                fs = h->fields_size;
+                bs = h->body_size;
+        } else if (h->endian == SD_BUS_REVERSE_ENDIAN) {
+                fs = bswap_32(h->fields_size);
+                bs = bswap_32(h->body_size);
+        } else
+                return -EBADMSG;
 
-        return
-                sizeof(*m->header) +
-                ALIGN8(m->header->fields_size) +
-                m->header->body_size;
+        *sum = sizeof(struct bus_header) + ALIGN8(fs) + bs;
+        return 0;
 }
diff --git a/src/libsystemd-bus/bus-message.h b/src/libsystemd-bus/bus-message.h
index 126ced0083..3d1bb62334 100644
--- a/src/libsystemd-bus/bus-message.h
+++ b/src/libsystemd-bus/bus-message.h
@@ -27,6 +27,7 @@
 
 #include "macro.h"
 #include "sd-bus.h"
+#include "kdbus.h"
 
 struct bus_container {
         char enclosing;
@@ -74,11 +75,13 @@ struct sd_bus_message {
         bool free_header:1;
         bool free_fields:1;
         bool free_body:1;
+        bool free_kdbus:1;
         bool free_fds:1;
 
         struct bus_header *header;
         void *fields;
         void *body;
+        struct kdbus_msg *kdbus;
 
         char *label;
 
@@ -94,6 +97,8 @@ struct sd_bus_message {
         unsigned n_iovec;
 
         char *peeked_signature;
+
+        usec_t timeout;
 };
 
 #define BUS_MESSAGE_NEED_BSWAP(m) ((m)->header->endian != SD_BUS_NATIVE_ENDIAN)
@@ -122,6 +127,13 @@ static inline uint32_t BUS_MESSAGE_FIELDS_SIZE(sd_bus_message *m) {
         return BUS_MESSAGE_BSWAP32(m, m->header->fields_size);
 }
 
+static inline uint32_t BUS_MESSAGE_SIZE(sd_bus_message *m) {
+        return
+                sizeof(struct bus_header) +
+                ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m)) +
+                BUS_MESSAGE_BODY_SIZE(m);
+}
+
 static inline void bus_message_unrefp(sd_bus_message **m) {
         sd_bus_message_unref(*m);
 }
@@ -133,6 +145,16 @@ int bus_message_dump(sd_bus_message *m);
 int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz);
 int bus_message_read_strv_extend(sd_bus_message *m, char ***l);
 
+int bus_message_from_header(
+                void *header,
+                size_t length,
+                int *fds,
+                unsigned n_fds,
+                const struct ucred *ucred,
+                const char *label,
+                size_t extra,
+                sd_bus_message **ret);
+
 int bus_message_from_malloc(
                 void *buffer,
                 size_t length,
@@ -146,4 +168,6 @@ const char* bus_message_get_arg(sd_bus_message *m, unsigned i);
 
 int bus_message_append_ap(sd_bus_message *m, const char *types, va_list ap);
 
-size_t bus_message_size(sd_bus_message *m);
+int bus_message_parse_fields(sd_bus_message *m);
+
+int bus_header_size(struct bus_header *h, size_t *sum);
diff --git a/src/libsystemd-bus/bus-socket.c b/src/libsystemd-bus/bus-socket.c
index 5e285c9e52..bce81aeffc 100644
--- a/src/libsystemd-bus/bus-socket.c
+++ b/src/libsystemd-bus/bus-socket.c
@@ -762,7 +762,7 @@ int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) {
         assert(idx);
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
-        if (*idx >= bus_message_size(m))
+        if (*idx >= BUS_MESSAGE_SIZE(m))
                 return 0;
 
         bus_message_setup_iovec(m);
diff --git a/src/libsystemd-bus/kdbus.h b/src/libsystemd-bus/kdbus.h
new file mode 100644
index 0000000000..ba59fd0d37
--- /dev/null
+++ b/src/libsystemd-bus/kdbus.h
@@ -0,0 +1,360 @@
+/*
+ * Copyright (C) 2013 Kay Sievers
+ * Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef _KDBUS_H_
+#define _KDBUS_H_
+
+#ifndef __KERNEL__
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/types.h>
+#endif
+
+#define KDBUS_IOC_MAGIC			0x95
+
+/* Message sent from kernel to userspace, when the owner or starter of
+ * a well-known name changes */
+struct kdbus_manager_msg_name_change {
+	__u64 old_id;
+	__u64 new_id;
+	__u64 flags;		/* 0 or (possibly?) KDBUS_CMD_NAME_IN_QUEUE */
+	char name[0];
+};
+
+struct kdbus_manager_msg_id_change {
+	__u64 id;
+	__u64 flags; /* The kernel flags field from KDBUS_CMD_HELLO */
+};
+
+struct kdbus_creds {
+	__u64 uid;
+	__u64 gid;
+	__u64 pid;
+	__u64 tid;
+
+	/* The starttime of the process PID. This is useful to detect
+	PID overruns from the client side. i.e. if you use the PID to
+	look something up in /proc/$PID/ you can afterwards check the
+	starttime field of it to ensure you didn't run into a PID
+	ovretun. */
+	__u64 starttime;
+};
+
+#define KDBUS_SRC_ID_KERNEL		(0)
+#define KDBUS_DST_ID_WELL_KNOWN_NAME	(0)
+#define KDBUS_MATCH_SRC_ID_ANY		(~0ULL)
+#define KDBUS_DST_ID_BROADCAST		(~0ULL)
+
+/* Message Data Types */
+enum {
+	/* Filled in by userspace */
+	KDBUS_MSG_NULL,			/* empty record */
+	KDBUS_MSG_PAYLOAD,		/* .data */
+	KDBUS_MSG_PAYLOAD_VEC,		/* .data_vec, converted into _PAYLOAD at delivery */
+	KDBUS_MSG_MMAP,			/* .data_vec */
+	KDBUS_MSG_MMAP_DONATE,		/* .data_vec, unmap the memory from the sender */
+	KDBUS_MSG_UNIX_FDS,		/* .data_fds of file descriptors */
+	KDBUS_MSG_BLOOM,		/* for broadcasts, carries bloom filter blob */
+	KDBUS_MSG_DST_NAME,		/* destination's well-known name */
+
+	/* Filled in by kernelspace */
+	KDBUS_MSG_SRC_NAMES	= 0x200,/* NUL separated string list with well-known names of source */
+	KDBUS_MSG_TIMESTAMP,		/* .ts_ns of CLOCK_MONOTONIC */
+	KDBUS_MSG_SRC_CREDS,		/* .creds */
+	KDBUS_MSG_SRC_COMM,		/* optional */
+	KDBUS_MSG_SRC_EXE,		/* optional */
+	KDBUS_MSG_SRC_CMDLINE,		/* optional */
+	KDBUS_MSG_SRC_CGROUP,		/* optional, specified which one */
+	KDBUS_MSG_SRC_CAPS,		/* caps data blob */
+	KDBUS_MSG_SRC_SECLABEL,		/* NUL terminated string */
+	KDBUS_MSG_SRC_AUDIT,		/* array of two uint64_t of audit loginuid + sessiond */
+
+	/* Special messages from kernel, consisting of one and only one of these data blocks */
+	KDBUS_MSG_NAME_ADD	= 0x400,/* .name_change */
+	KDBUS_MSG_NAME_REMOVE,		/* .name_change */
+	KDBUS_MSG_NAME_CHANGE,		/* .name_change */
+	KDBUS_MSG_ID_ADD,		/* .id_change */
+	KDBUS_MSG_ID_REMOVE,		/* .id_change */
+	KDBUS_MSG_ID_CHANGE,		/* .id_change */
+	KDBUS_MSG_REPLY_TIMEOUT,	/* empty, but .reply_cookie in .kdbus_msg is filled in */
+	KDBUS_MSG_REPLY_DEAD,		/* dito */
+};
+
+struct kdbus_vec {
+	__u64 address;
+	__u64 size;
+};
+
+/**
+ * struct  kdbus_msg_data - chain of data blocks
+ *
+ * size: overall data record size
+ * type: kdbus_msg_data_type of data
+ */
+struct kdbus_msg_data {
+	__u64 size;
+	__u64 type;
+	union {
+		/* inline data */
+		__u8 data[0];
+		__u32 data_u32[0];
+		__u64 data_u64[0];
+
+		/* data vector */
+		struct kdbus_vec vec;
+
+		/* specific fields */
+		int fds[0];				/* int array of file descriptors */
+		__u64 ts_ns;				/* timestamp in nanoseconds */
+		struct kdbus_creds creds;
+		struct kdbus_manager_msg_name_change name_change;
+		struct kdbus_manager_msg_id_change id_change;
+	};
+};
+
+enum {
+	KDBUS_MSG_FLAGS_EXPECT_REPLY	= 1,
+	KDBUS_MSG_FLAGS_NO_AUTO_START	= 2, /* possibly? */
+};
+
+enum {
+	KDBUS_PAYLOAD_NONE	= 0,
+	KDBUS_PAYLOAD_DBUS1	= 0x4442757356657231ULL, /* 'DBusVer1' */
+	KDBUS_PAYLOAD_GVARIANT	= 0x4756617269616e74ULL, /* 'GVariant' */
+};
+
+/**
+ * struct kdbus_msg
+ *
+ * set by userspace:
+ * dst_id: destination id
+ * flags: KDBUS_MSG_FLAGS_*
+ * data_size: overall message size
+ * data: data records
+ *
+ * set by kernel:
+ * src_id: who sent the message
+ */
+struct kdbus_msg {
+	__u64 size;
+	__u64 flags;
+	__u64 dst_id;		/* connection, 0 == name in data, ~0 broadcast */
+	__u64 src_id;		/* connection, 0 == kernel */
+	__u64 payload_type;	/* 'DBusVer1', 'GVariant', ... */
+	__u64 cookie;		/* userspace-supplied cookie */
+	union {
+		__u64 cookie_reply;	/* cookie we reply to */
+		__u64 timeout_ns;	/* timespan to wait for reply */
+	};
+	struct kdbus_msg_data data[0];
+};
+
+enum {
+	KDBUS_POLICY_NAME,
+	KDBUS_POLICY_ACCESS,
+};
+
+enum {
+	KDBUS_POLICY_USER,
+	KDBUS_POLICY_GROUP,
+	KDBUS_POLICY_WORLD,
+};
+
+enum {
+	KDBUS_POLICY_RECV	= 4,
+	KDBUS_POLICY_SEND	= 2,
+	KDBUS_POLICY_OWN	= 1,
+};
+
+struct kdbus_policy {
+	__u64 size;
+	__u64 type; /* NAME or ACCESS */
+	union {
+		char name[0];
+		struct {
+			__u32 type;	/* USER, GROUP, WORLD */
+			__u32 bits;	/* RECV, SEND, OWN */
+			__u64 id;	/* uid, gid, 0 */
+		} access;
+	};
+};
+
+struct kdbus_cmd_policy {
+	__u64 size;
+	__u8 buffer[0];	/* a series of KDBUS_POLICY_NAME plus one or more KDBUS_POLICY_ACCESS each. */
+};
+
+enum {
+	KDBUS_CMD_HELLO_STARTER		=  1,
+	KDBUS_CMD_HELLO_ACCEPT_FD	=  2,
+	KDBUS_CMD_HELLO_ACCEPT_MMAP	=  4,
+};
+
+enum {
+	KDBUS_CMD_FNAME_ACCESS_GROUP	=  1,
+	KDBUS_CMD_FNAME_ACCESS_WORLD	=  2,
+};
+
+struct kdbus_cmd_hello {
+	/* userspace → kernel, kernel → userspace */
+	__u64 kernel_flags;	/* userspace specifies its
+				 * capabilities and more, kernel
+				 * returns its capabilites and
+				 * more. Kernel might refuse client's
+				 * capabilities by returning an error
+				 * from KDBUS_CMD_HELLO */
+
+	/* userspace → kernel */
+	__u64 pid;		/* To allow translator services which
+				 * connect to the bus on behalf of
+				 * somebody else, allow specifiying
+				 * the PID of the client to connect on
+				 * behalf on. Normal clients should
+				 * pass this as 0 (i.e. to do things
+				 * under their own PID). Priviliged
+				 * clients can pass != 0, to operate
+				 * on behalf of somebody else. */
+
+	/* kernel → userspace */
+	__u64 bus_flags;	/* this is .flags copied verbatim from
+				 * from original KDBUS_CMD_BUS_MAKE
+				 * ioctl. It's intended to be useful
+				 * to do negotiation of features of
+				 * the payload that is transfreted. */
+	__u64 id;		/* peer id */
+};
+
+struct kdbus_cmd_fname {
+	__u64 size;
+	__u64 kernel_flags;	/* userspace → kernel, kernel → userspace
+				 * When creating a bus/ns/ep feature
+				 * kernel negotiation done the same
+				 * way as for KDBUS_CMD_BUS_MAKE. */
+	__u64 user_flags;	/* userspace → kernel
+				 * When a bus is created this value is
+				 * copied verbatim into the bus
+				 * structure and returned from
+				 * KDBUS_CMD_HELLO, later */
+	char name[0];
+};
+
+enum {
+	/* userspace → kernel */
+	KDBUS_CMD_NAME_REPLACE_EXISTING		=  1,
+	KDBUS_CMD_NAME_QUEUE			=  2,
+	KDBUS_CMD_NAME_ALLOW_REPLACEMENT	=  4,
+	KDBUS_CMD_NAME_STEAL_MESSAGES		=  8,
+
+	/* kernel → userspace */
+	KDBUS_CMD_NAME_IN_QUEUE = 0x200,
+};
+
+struct kdbus_cmd_name {
+	__u64 size;
+	__u64 flags;
+	__u64 id;		/* We allow registration/deregestration of names of other peers */
+	char name[0];
+};
+
+struct kdbus_cmd_names {
+	__u64 size;
+	struct kdbus_cmd_name names[0];
+};
+
+enum {
+	KDBUS_CMD_NAME_INFO_ITEM_NAME,
+	KDBUS_CMD_NAME_INFO_ITEM_SECLABEL,
+	KDBUS_CMD_NAME_INFO_ITEM_AUDIT,
+};
+
+struct kdbus_cmd_name_info_item {
+	__u64 size;
+	__u64 type;
+	__u8 data[0];
+};
+
+struct kdbus_cmd_name_info {
+	__u64 size;			/* overall size of info */
+	__u64 flags;
+	__u64 id;			/* either ID, or 0 and _ITEM_NAME follows */
+	struct kdbus_creds creds;
+	struct kdbus_cmd_name_info_item item[0]; /* list of item records */
+};
+
+enum {
+	KDBUS_CMD_MATCH_BLOOM,		/* Matches a mask blob against KDBUS_MSG_BLOOM */
+	KDBUS_CMD_MATCH_SRC_NAME,	/* Matches a name string against KDBUS_MSG_SRC_NAMES */
+	KDBUS_CMD_MATCH_NAME_ADD,	/* Matches a name string against KDBUS_MSG_NAME_ADD */
+	KDBUS_CMD_MATCH_NAME_REMOVE,	/* Matches a name string against KDBUS_MSG_NAME_REMOVE */
+	KDBUS_CMD_MATCH_NAME_CHANGE,	/* Matches a name string against KDBUS_MSG_NAME_CHANGE */
+	KDBUS_CMD_MATCH_ID_ADD,		/* Matches an ID against KDBUS_MSG_ID_ADD */
+	KDBUS_CMD_MATCH_ID_REMOVE,	/* Matches an ID against KDBUS_MSG_ID_REMOVE */
+	KDBUS_CMD_MATCH_ID_CHANGE,	/* Matches an ID against KDBUS_MSG_ID_CHANGE */
+};
+
+struct kdbus_cmd_match_item {
+	__u64 size;
+	__u64 type;
+	__u8 data[0];
+};
+
+struct kdbus_cmd_match {
+	__u64 size;
+	__u64 id;	/* We allow registration/deregestration of matches for other peers */
+	__u64 cookie;	/* userspace supplied cookie; when removing; kernel deletes everything with same cookie */
+	__u64 src_id;	/* ~0: any. other: exact unique match */
+	struct kdbus_cmd_match_item items[0];
+};
+
+struct kdbus_cmd_monitor {
+	__u64 id;		/* We allow setting the monitor flag of other peers */
+	int enabled;		/* A boolean to enable/disable monitoring */
+};
+
+/* FD states:
+ * control nodes: unset
+ *   bus owner  (via KDBUS_CMD_BUS_MAKE)
+ *   ns owner   (via KDBUS_CMD_NS_MAKE)
+ *
+ * ep nodes: unset
+ *   connected  (via KDBUS_CMD_HELLO)
+ *   starter    (via KDBUS_CMD_HELLO with KDBUS_CMD_HELLO_STARTER)
+ *   ep owner   (via KDBUS_CMD_EP_MAKE)
+ */
+enum kdbus_cmd {
+	/* kdbus control node commands: require unset state */
+	KDBUS_CMD_BUS_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x00, struct kdbus_cmd_fname),
+	KDBUS_CMD_NS_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x10, struct kdbus_cmd_fname),
+
+	/* kdbus control node commands: require bus owner state */
+	KDBUS_CMD_BUS_POLICY_SET =	_IOWR(KDBUS_IOC_MAGIC, 0x20, struct kdbus_cmd_policy),
+
+	/* kdbus ep node commands: require unset state */
+	KDBUS_CMD_EP_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x30, struct kdbus_cmd_fname),
+	KDBUS_CMD_HELLO =		_IOWR(KDBUS_IOC_MAGIC, 0x31, struct kdbus_cmd_hello),
+
+	/* kdbus ep node commands: require connected state */
+	KDBUS_CMD_MSG_SEND =		_IOWR(KDBUS_IOC_MAGIC, 0x40, struct kdbus_msg),
+	KDBUS_CMD_MSG_RECV =		_IOWR(KDBUS_IOC_MAGIC, 0x41, struct kdbus_msg),
+
+	KDBUS_CMD_NAME_ACQUIRE =	_IOWR(KDBUS_IOC_MAGIC, 0x50, struct kdbus_cmd_name),
+	KDBUS_CMD_NAME_RELEASE =	_IOWR(KDBUS_IOC_MAGIC, 0x51, struct kdbus_cmd_name),
+	KDBUS_CMD_NAME_LIST =		_IOWR(KDBUS_IOC_MAGIC, 0x52, struct kdbus_cmd_names),
+	KDBUS_CMD_NAME_QUERY =		_IOWR(KDBUS_IOC_MAGIC, 0x53, struct kdbus_cmd_name_info),
+
+	KDBUS_CMD_MATCH_ADD =		_IOWR(KDBUS_IOC_MAGIC, 0x60, struct kdbus_cmd_match),
+	KDBUS_CMD_MATCH_REMOVE =	_IOWR(KDBUS_IOC_MAGIC, 0x61, struct kdbus_cmd_match),
+	KDBUS_CMD_MONITOR =		_IOWR(KDBUS_IOC_MAGIC, 0x62, struct kdbus_cmd_monitor),
+
+	/* kdbus ep node commands: require ep owner state */
+	KDBUS_CMD_EP_POLICY_SET =	_IOWR(KDBUS_IOC_MAGIC, 0x70, struct kdbus_cmd_policy),
+};
+#endif
diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 89172e6369..29487cbd31 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -37,6 +37,7 @@
 #include "bus-message.h"
 #include "bus-type.h"
 #include "bus-socket.h"
+#include "bus-kernel.h"
 #include "bus-control.h"
 
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
@@ -259,7 +260,7 @@ static int bus_send_hello(sd_bus *bus) {
 
         assert(bus);
 
-        if (!bus->bus_client)
+        if (!bus->bus_client || bus->is_kernel)
                 return 0;
 
         r = sd_bus_message_new_method_call(
@@ -596,6 +597,41 @@ fail:
         return r;
 }
 
+static int parse_kernel_address(sd_bus *b, const char **p, char **guid) {
+        _cleanup_free_ char *path = NULL;
+        int r;
+
+        assert(b);
+        assert(p);
+        assert(*p);
+        assert(guid);
+
+        while (**p != 0 && **p != ';') {
+                r = parse_address_key(p, "guid", guid);
+                if (r < 0)
+                        return r;
+                else if (r > 0)
+                        continue;
+
+                r = parse_address_key(p, "path", &path);
+                if (r < 0)
+                        return r;
+                else if (r > 0)
+                        continue;
+
+                skip_address_key(p);
+        }
+
+        if (!path)
+                return -EINVAL;
+
+        free(b->kernel);
+        b->kernel = path;
+        path = NULL;
+
+        return 0;
+}
+
 static void bus_reset_parsed_address(sd_bus *b) {
         assert(b);
 
@@ -606,6 +642,8 @@ static void bus_reset_parsed_address(sd_bus *b) {
         b->exec_path = NULL;
         b->exec_argv = NULL;
         b->server_id = SD_ID128_NULL;
+        free(b->kernel);
+        b->kernel = NULL;
 }
 
 static int bus_parse_next_address(sd_bus *b) {
@@ -657,6 +695,14 @@ static int bus_parse_next_address(sd_bus *b) {
 
                         break;
 
+                } else if (startswith(a, "kernel:")) {
+
+                        a += 7;
+                        r = parse_kernel_address(b, &a, &guid);
+                        if (r < 0)
+                                return r;
+
+                        break;
                 }
 
                 a = strchr(a, ';');
@@ -697,6 +743,13 @@ static int bus_start_address(sd_bus *b) {
                                 return r;
 
                         b->last_connect_error = -r;
+                } else if (b->kernel) {
+
+                        r = bus_kernel_connect(b);
+                        if (r >= 0)
+                                return r;
+
+                        b->last_connect_error = -r;
                 }
 
                 r = bus_parse_next_address(b);
@@ -715,6 +768,7 @@ int bus_next_address(sd_bus *b) {
 }
 
 static int bus_start_fd(sd_bus *b) {
+        struct stat st;
         int r;
 
         assert(b);
@@ -739,7 +793,13 @@ static int bus_start_fd(sd_bus *b) {
                         return r;
         }
 
-        return bus_socket_take_fd(b);
+        if (fstat(b->input_fd, &st) < 0)
+                return -errno;
+
+        if (S_ISCHR(b->input_fd))
+                return bus_kernel_take_fd(b);
+        else
+                return bus_socket_take_fd(b);
 }
 
 int sd_bus_start(sd_bus *bus) {
@@ -757,7 +817,7 @@ int sd_bus_start(sd_bus *bus) {
 
         if (bus->input_fd >= 0)
                 r = bus_start_fd(bus);
-        else if (bus->address || bus->sockaddr.sa.sa_family != AF_UNSPEC || bus->exec_path)
+        else if (bus->address || bus->sockaddr.sa.sa_family != AF_UNSPEC || bus->exec_path || bus->kernel)
                 r = bus_start_address(bus);
         else
                 return -EINVAL;
@@ -958,14 +1018,18 @@ static int dispatch_wqueue(sd_bus *bus) {
 
         while (bus->wqueue_size > 0) {
 
-                r = bus_socket_write_message(bus, bus->wqueue[0], &bus->windex);
+                if (bus->is_kernel)
+                        r = bus_kernel_write_message(bus, bus->wqueue[0]);
+                else
+                        r = bus_socket_write_message(bus, bus->wqueue[0], &bus->windex);
+
                 if (r < 0) {
                         sd_bus_close(bus);
                         return r;
                 } else if (r == 0)
                         /* Didn't do anything this time */
                         return ret;
-                else if (bus->windex >= bus_message_size(bus->wqueue[0])) {
+                else if (bus->is_kernel || bus->windex >= BUS_MESSAGE_SIZE(bus->wqueue[0])) {
                         /* Fully written. Let's drop the entry from
                          * the queue.
                          *
@@ -1010,7 +1074,11 @@ static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
 
         /* Try to read a new message */
         do {
-                r = bus_socket_read_message(bus, &z);
+                if (bus->is_kernel)
+                        r = bus_kernel_read_message(bus, &z);
+                else
+                        r = bus_socket_read_message(bus, &z);
+
                 if (r < 0) {
                         sd_bus_close(bus);
                         return r;
@@ -1062,11 +1130,15 @@ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
         if ((bus->state == BUS_RUNNING || bus->state == BUS_HELLO) && bus->wqueue_size <= 0) {
                 size_t idx = 0;
 
-                r = bus_socket_write_message(bus, m, &idx);
+                if (bus->is_kernel)
+                        r = bus_kernel_write_message(bus, m);
+                else
+                        r = bus_socket_write_message(bus, m, &idx);
+
                 if (r < 0) {
                         sd_bus_close(bus);
                         return r;
-                } else if (idx < bus_message_size(m))  {
+                } else if (!bus->is_kernel && idx < BUS_MESSAGE_SIZE(m))  {
                         /* Wasn't fully written. So let's remember how
                          * much was written. Note that the first entry
                          * of the wqueue array is always allocated so
@@ -1304,7 +1376,10 @@ int sd_bus_send_with_reply_and_block(
                         room = true;
                 }
 
-                r = bus_socket_read_message(bus, &incoming);
+                if (bus->is_kernel)
+                        r = bus_kernel_read_message(bus, &incoming);
+                else
+                        r = bus_socket_read_message(bus, &incoming);
                 if (r < 0)
                         return r;
                 if (incoming) {