bus: add new sd_bus_creds object to encapsulate process credentials

This way we can unify handling of credentials that are attached to
messages, or can be queried for bus name owners or connection peers.

This also adds the ability to extend incomplete credential information
with data from /proc,

Also, provide a convenience call that will automatically determine the
most appropriate credential object for an incoming message, by using the
the attached information if possible, the sending name information if
available and otherwise the peer's credentials.

1 files changed, 16 insertions, 218 deletions

diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index 132426f6fd..dd058e72c4 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -143,16 +143,12 @@ static void message_free(sd_bus_message *m) {
         if (m->iovec != m->iovec_fixed)
                 free(m->iovec);
 
-        free(m->cmdline_array);
-
         message_reset_containers(m);
         free(m->root_container.signature);
 
         free(m->peeked_signature);
 
-        free(m->unit);
-        free(m->user_unit);
-        free(m->session);
+        bus_creds_done(&m->creds);
         free(m);
 }
 
@@ -358,15 +354,17 @@ int bus_message_from_header(
         m->n_fds = n_fds;
 
         if (ucred) {
-                m->uid = ucred->uid;
-                m->pid = ucred->pid;
-                m->gid = ucred->gid;
-                m->uid_valid = m->gid_valid = true;
+                m->creds.uid = ucred->uid;
+                m->creds.pid = ucred->pid;
+                m->creds.gid = ucred->gid;
+                m->creds.mask |= SD_BUS_CREDS_UID | SD_BUS_CREDS_PID | SD_BUS_CREDS_GID;
         }
 
         if (label) {
-                m->label = (char*) m + ALIGN(sizeof(sd_bus_message)) + ALIGN(extra);
-                memcpy(m->label, label, label_sz + 1);
+                m->creds.label = (char*) m + ALIGN(sizeof(sd_bus_message)) + ALIGN(extra);
+                memcpy(m->creds.label, label, label_sz + 1);
+
+                m->creds.mask |= SD_BUS_CREDS_SELINUX_CONTEXT;
         }
 
         if (bus)
@@ -811,63 +809,10 @@ _public_ const sd_bus_error *sd_bus_message_get_error(sd_bus_message *m) {
         return &m->error;
 }
 
-_public_ int sd_bus_message_get_uid(sd_bus_message *m, uid_t *uid) {
-        assert_return(m, -EINVAL);
-        assert_return(uid, -EINVAL);
-        assert_return(m->uid_valid, -ESRCH);
-
-        *uid = m->uid;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_gid(sd_bus_message *m, gid_t *gid) {
-        assert_return(m, -EINVAL);
-        assert_return(gid, -EINVAL);
-        assert_return(m->gid_valid, -ESRCH);
-
-        *gid = m->gid;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_pid(sd_bus_message *m, pid_t *pid) {
-        assert_return(m, -EINVAL);
-        assert_return(pid, -EINVAL);
-        assert_return(m->pid > 0, -ESRCH);
-
-        *pid = m->pid;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_tid(sd_bus_message *m, pid_t *tid) {
-        assert_return(m, -EINVAL);
-        assert_return(tid, -EINVAL);
-        assert_return(m->tid > 0, -ESRCH);
-
-        *tid = m->tid;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_pid_starttime(sd_bus_message *m, uint64_t *usec) {
-        assert_return(m, -EINVAL);
-        assert_return(usec, -EINVAL);
-        assert_return(m->pid_starttime > 0, -ESRCH);
-
-        *usec = m->pid_starttime;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_selinux_context(sd_bus_message *m, const char **ret) {
-        assert_return(m, -EINVAL);
-        assert_return(m->label, -ESRCH);
-
-        *ret = m->label;
-        return 0;
-}
-
 _public_ int sd_bus_message_get_monotonic_timestamp(sd_bus_message *m, uint64_t *usec) {
         assert_return(m, -EINVAL);
         assert_return(usec, -EINVAL);
-        assert_return(m->monotonic > 0, -ESRCH);
+        assert_return(m->monotonic > 0, -ENODATA);
 
         *usec = m->monotonic;
         return 0;
@@ -876,166 +821,19 @@ _public_ int sd_bus_message_get_monotonic_timestamp(sd_bus_message *m, uint64_t
 _public_ int sd_bus_message_get_realtime_timestamp(sd_bus_message *m, uint64_t *usec) {
         assert_return(m, -EINVAL);
         assert_return(usec, -EINVAL);
-        assert_return(m->realtime > 0, -ESRCH);
+        assert_return(m->realtime > 0, -ENODATA);
 
         *usec = m->realtime;
         return 0;
 }
 
-_public_ int sd_bus_message_get_comm(sd_bus_message *m, const char **ret) {
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->comm, -ESRCH);
-
-        *ret = m->comm;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_tid_comm(sd_bus_message *m, const char **ret) {
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->tid_comm, -ESRCH);
-
-        *ret = m->tid_comm;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_exe(sd_bus_message *m, const char **ret) {
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->exe, -ESRCH);
-
-        *ret = m->exe;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_cgroup(sd_bus_message *m, const char **ret) {
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->cgroup, -ESRCH);
-
-        *ret = m->cgroup;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_unit(sd_bus_message *m, const char **ret) {
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->cgroup, -ESRCH);
-
-        if (!m->unit) {
-                r = cg_path_get_unit(m->cgroup, &m->unit);
-                if (r < 0)
-                        return r;
-        }
-
-        *ret = m->unit;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_user_unit(sd_bus_message *m, const char **ret) {
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->cgroup, -ESRCH);
-
-        if (!m->user_unit) {
-                r = cg_path_get_user_unit(m->cgroup, &m->user_unit);
-                if (r < 0)
-                        return r;
-        }
-
-        *ret = m->user_unit;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_session(sd_bus_message *m, const char **ret) {
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(ret, -EINVAL);
-        assert_return(m->cgroup, -ESRCH);
-
-        if (!m->session) {
-                r = cg_path_get_session(m->cgroup, &m->session);
-                if (r < 0)
-                        return r;
-        }
-
-        *ret = m->session;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_owner_uid(sd_bus_message *m, uid_t *uid) {
-        assert_return(m, -EINVAL);
-        assert_return(uid, -EINVAL);
-        assert_return(m->cgroup, -ESRCH);
-
-        return cg_path_get_owner_uid(m->cgroup, uid);
-}
-
-_public_ int sd_bus_message_get_cmdline(sd_bus_message *m, char ***cmdline) {
-        size_t n, i;
-        const char *p;
-        bool first;
-
-        assert_return(m, -EINVAL);
-        assert_return(m->cmdline, -ESRCH);
-
-        for (p = m->cmdline, n = 0; p < m->cmdline + m->cmdline_length; p++)
-                if (*p == 0)
-                        n++;
-
-        m->cmdline_array = new(char*, n + 1);
-        if (!m->cmdline_array)
-                return -ENOMEM;
-
-        for (p = m->cmdline, i = 0, first = true; p < m->cmdline + m->cmdline_length; p++) {
-                if (first)
-                        m->cmdline_array[i++] = (char*) p;
-
-                first = *p == 0;
-        }
-
-        m->cmdline_array[i] = NULL;
-        *cmdline = m->cmdline_array;
-
-        return 0;
-}
-
-_public_ int sd_bus_message_get_audit_sessionid(sd_bus_message *m, uint32_t *sessionid) {
-        assert_return(m, -EINVAL);
-        assert_return(sessionid, -EINVAL);
-        assert_return(m->audit, -ESRCH);
-
-        *sessionid = m->audit->sessionid;
-        return 0;
-}
-
-_public_ int sd_bus_message_get_audit_loginuid(sd_bus_message *m, uid_t *uid) {
-        assert_return(m, -EINVAL);
-        assert_return(uid, -EINVAL);
-        assert_return(m->audit, -ESRCH);
-
-        *uid = m->audit->loginuid;
-        return 0;
-}
-
-_public_ int sd_bus_message_has_effective_cap(sd_bus_message *m, int capability) {
-        unsigned sz;
-
-        assert_return(m, -EINVAL);
-        assert_return(capability < 0, -EINVAL);
-        assert_return(!m->capability, -ESRCH);
+_public_ sd_bus_creds *sd_bus_message_get_creds(sd_bus_message *m) {
+        assert_return(m, NULL);
 
-        sz = m->capability_size / 4;
-        if ((unsigned) capability >= sz*8)
-                return 0;
+        if (m->creds.mask == 0)
+                return NULL;
 
-        return !!(m->capability[2 * sz + (capability / 8)] & (1 << (capability % 8)));
+        return &m->creds;
 }
 
 _public_ int sd_bus_message_is_signal(sd_bus_message *m,