bus: align the buffer we pass to the kernel

[elogind.git] / src / libsystemd-bus / bus-kernel.c

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index b83dfcbc27bca1b37ecde52840b3302437d7b872..d5152ec6d27936d9e9d7a9ac5934dcacbbc5f504 100644 (file)
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -19,6 +19,10 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+#include <valgrind/memcheck.h>
+#endif
+
 #include <fcntl.h>
 
 #include "util.h"
@@ -32,8 +36,6 @@
              (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;
 
@@ -83,7 +85,9 @@ static int bus_message_setup_kmsg(sd_bus_message *m) {
 
         assert(m);
         assert(m->sealed);
-        assert(!m->kdbus);
+
+        if (m->kdbus)
+                return 0;
 
         if (m->destination) {
                 r = parse_unique_name(m->destination, &unique);
@@ -105,7 +109,7 @@ static int bus_message_setup_kmsg(sd_bus_message *m) {
                 sz += ALIGN8(offsetof(struct kdbus_msg, data) + dl + 1);
         }
 
-        m->kdbus = malloc0(sz);
+        m->kdbus = aligned_alloc(8, sz);
         if (!m->kdbus)
                 return -ENOMEM;
 
@@ -140,9 +144,11 @@ static int bus_message_setup_kmsg(sd_bus_message *m) {
         if (m->body)
                 append_payload_vec(&d, m->body, m->header->body_size);
 
-        m->kdbus->size = (uint8_t*) m - (uint8_t*) m->kdbus;
+        m->kdbus->size = (uint8_t*) d - (uint8_t*) m->kdbus;
         assert(m->kdbus->size <= sz);
 
+        m->free_kdbus = true;
+
         return 0;
 }
 
@@ -152,6 +158,9 @@ int bus_kernel_take_fd(sd_bus *b) {
 
         assert(b);
 
+        if (b->is_server)
+                return -EINVAL;
+
         r = ioctl(b->input_fd, KDBUS_CMD_HELLO, &hello);
         if (r < 0)
                 return -errno;
@@ -160,6 +169,7 @@ int bus_kernel_take_fd(sd_bus *b) {
                 return -ENOMEM;
 
         b->is_kernel = true;
+        b->bus_client = true;
 
         r = bus_start_running(b);
         if (r < 0)
@@ -174,6 +184,9 @@ int bus_kernel_connect(sd_bus *b) {
         assert(b->output_fd < 0);
         assert(b->kernel);
 
+        if (b->is_server)
+                return -EINVAL;
+
         b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (b->input_fd < 0)
                 return -errno;
@@ -220,6 +233,8 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
         _cleanup_free_ int *fds = NULL;
         struct bus_header *h = NULL;
         size_t total, n_bytes = 0, idx = 0;
+        struct kdbus_creds *creds = NULL;
+        uint64_t nsec = 0;
         int r;
 
         assert(bus);
@@ -258,7 +273,11 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         fds = f;
                         memcpy(fds + n_fds, d->fds, j);
                         n_fds += j;
-                }
+
+                } else if (d->type == KDBUS_MSG_SRC_CREDS)
+                        creds = &d->creds;
+                else if (d->type == KDBUS_MSG_TIMESTAMP)
+                        nsec = d->ts_ns;
         }
 
         if (!h)
@@ -282,14 +301,14 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         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 {
+                else if (!(idx == 0 && l == sizeof(struct bus_header)) &&
+                         !(idx == sizeof(struct bus_header) + BUS_MESSAGE_FIELDS_SIZE(m))) {
                         sd_bus_message_unref(m);
                         return -EBADMSG;
                 }
@@ -297,6 +316,17 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                 idx += l;
         }
 
+        if (creds) {
+                m->pid_starttime = creds->starttime / NSEC_PER_USEC;
+                m->uid = creds->uid;
+                m->gid = creds->gid;
+                m->pid = creds->pid;
+                m->tid = creds->tid;
+                m->uid_valid = m->gid_valid = true;
+        }
+
+        m->timestamp = nsec / NSEC_PER_USEC;
+
         r = bus_message_parse_fields(m);
         if (r < 0) {
                 sd_bus_message_unref(m);
@@ -316,7 +346,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
 
 int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
         struct kdbus_msg *k;
-        size_t sz = 128;
+        size_t sz = 1024;
         int r;
 
         assert(bus);
@@ -325,13 +355,21 @@ int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
         for (;;) {
                 void *q;
 
-                q = realloc(bus->rbuffer, sz);
+                q = aligned_alloc(8, sz);
                 if (!q)
                         return -errno;
 
+                free(bus->rbuffer);
                 k = bus->rbuffer = q;
                 k->size = sz;
 
+                /* Let's tell valgrind that there's really no need to
+                 * initialize this fully. This should be removed again
+                 * when valgrind learned the kdbus ioctls natively. */
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+                VALGRIND_MAKE_MEM_DEFINED(k, sz);
+#endif
+
                 r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, bus->rbuffer);
                 if (r >= 0)
                         break;
@@ -339,7 +377,7 @@ int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
                 if (errno == EAGAIN)
                         return 0;
 
-                if (errno != EMSGSIZE)
+                if (errno != ENOBUFS)
                         return -errno;
 
                 sz *= 2;
@@ -371,7 +409,7 @@ int bus_kernel_create(const char *name, char **s) {
         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->kernel_flags = KDBUS_CMD_FNAME_ACCESS_WORLD | KDBUS_CMD_FNAME_POLICY_NONE;
         fname->user_flags = 0;
 
         p = strjoin("/dev/kdbus/", fname->name, "/bus", NULL);