journal: allow callers to specify OBJECT_PID=

When journald encounters a message with OBJECT_PID= set
coming from a priviledged process (UID==0), additional fields
will be added to the message:

OBJECT_UID=,
OBJECT_GID=,
OBJECT_COMM=,
OBJECT_EXE=,
OBJECT_CMDLINE=,
OBJECT_AUDIT_SESSION=,
OBJECT_AUDIT_LOGINUID=,
OBJECT_SYSTEMD_CGROUP=,
OBJECT_SYSTEMD_SESSION=,
OBJECT_SYSTEMD_OWNER_UID=,
OBJECT_SYSTEMD_UNIT= or OBJECT_SYSTEMD_USER_UNIT=.

This is for other logging daemons, like setroubleshoot, to be able to
augment their logs with data about the process.

https://bugzilla.redhat.com/show_bug.cgi?id=951627

6 files changed, 157 insertions, 55 deletions

diff --git a/src/journal/journald-kmsg.c b/src/journal/journald-kmsg.c
index 5fd87b815..21649d06c 100644
--- a/src/journal/journald-kmsg.c
+++ b/src/journal/journald-kmsg.c
@@ -304,7 +304,7 @@ static void dev_kmsg_record(Server *s, char *p, size_t l) {
         if (message)
                 IOVEC_SET_STRING(iovec[n++], message);
 
-        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), NULL, NULL, NULL, 0, NULL, priority);
+        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), NULL, NULL, NULL, 0, NULL, priority, 0);
 
 finish:
         for (j = 0; j < z; j++)
diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
index ec9afa187..0f9af378c 100644
--- a/src/journal/journald-native.c
+++ b/src/journal/journald-native.c
@@ -71,6 +71,10 @@ static bool valid_user_field(const char *p, size_t l) {
         return true;
 }
 
+static bool allow_object_pid(struct ucred *ucred) {
+        return ucred && ucred->uid == 0;
+}
+
 void server_process_native_message(
                 Server *s,
                 const void *buffer, size_t buffer_size,
@@ -79,11 +83,12 @@ void server_process_native_message(
                 const char *label, size_t label_len) {
 
         struct iovec *iovec = NULL;
-        unsigned n = 0, m = 0, j, tn = (unsigned) -1;
+        unsigned n = 0, j, tn = (unsigned) -1;
         const char *p;
-        size_t remaining;
+        size_t remaining, m = 0;
         int priority = LOG_INFO;
         char *identifier = NULL, *message = NULL;
+        pid_t object_pid = 0;
 
         assert(s);
         assert(buffer || buffer_size == 0);
@@ -104,7 +109,7 @@ void server_process_native_message(
 
                 if (e == p) {
                         /* Entry separator */
-                        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority);
+                        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority, object_pid);
                         n = 0;
                         priority = LOG_INFO;
 
@@ -124,19 +129,10 @@ void server_process_native_message(
                 /* A property follows */
 
                 /* n received properties, +1 for _TRANSPORT */
-                if (n + 1 + N_IOVEC_META_FIELDS >= m) {
-                        struct iovec *c;
-                        unsigned u;
-
-                        u = MAX((n + 1 + N_IOVEC_META_FIELDS) * 2U, 4U);
-                        c = realloc(iovec, u * sizeof(struct iovec));
-                        if (!c) {
-                                log_oom();
-                                break;
-                        }
-
-                        iovec = c;
-                        m = u;
+                if (!GREEDY_REALLOC(iovec, m, n + 1 + N_IOVEC_META_FIELDS +
+                                              !!object_pid * N_IOVEC_OBJECT_FIELDS)) {
+                        log_oom();
+                        break;
                 }
 
                 q = memchr(p, '=', e - p);
@@ -191,6 +187,16 @@ void server_process_native_message(
                                                 free(message);
                                                 message = t;
                                         }
+                                } else if (l > strlen("OBJECT_PID=") &&
+                                           l < strlen("OBJECT_PID=")  + DECIMAL_STR_MAX(pid_t) &&
+                                           hasprefix(p, "OBJECT_PID=") &&
+                                           allow_object_pid(ucred)) {
+                                        char buf[DECIMAL_STR_MAX(pid_t)];
+                                        memcpy(buf, p + strlen("OBJECT_PID="), l - strlen("OBJECT_PID="));
+                                        char_array_0(buf);
+
+                                        /* ignore error */
+                                        parse_pid(buf, &object_pid);
                                 }
                         }
 
@@ -260,7 +266,7 @@ void server_process_native_message(
                         server_forward_console(s, priority, identifier, message, ucred);
         }
 
-        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority);
+        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority, object_pid);
 
 finish:
         for (j = 0; j < n; j++)  {
diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index de9604024..ae65f0289 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -499,24 +499,33 @@ static void dispatch_message_real(
                 struct ucred *ucred,
                 struct timeval *tv,
                 const char *label, size_t label_len,
-                const char *unit_id) {
+                const char *unit_id,
+                pid_t object_pid) {
 
-        char pid[sizeof("_PID=") + DECIMAL_STR_MAX(pid_t)],
+        char    pid[sizeof("_PID=") + DECIMAL_STR_MAX(pid_t)],
                 uid[sizeof("_UID=") + DECIMAL_STR_MAX(uid_t)],
                 gid[sizeof("_GID=") + DECIMAL_STR_MAX(gid_t)],
                 owner_uid[sizeof("_SYSTEMD_OWNER_UID=") + DECIMAL_STR_MAX(uid_t)],
                 source_time[sizeof("_SOURCE_REALTIME_TIMESTAMP=") + DECIMAL_STR_MAX(usec_t)],
                 boot_id[sizeof("_BOOT_ID=") + 32] = "_BOOT_ID=",
-                machine_id[sizeof("_MACHINE_ID=") + 32] = "_MACHINE_ID=";
-        char *comm, *exe, *cmdline, *cgroup, *session, *unit, *hostname;
+                machine_id[sizeof("_MACHINE_ID=") + 32] = "_MACHINE_ID=",
+                o_uid[sizeof("OBJECT_UID=") + DECIMAL_STR_MAX(uid_t)],
+                o_gid[sizeof("OBJECT_GID=") + DECIMAL_STR_MAX(gid_t)],
+                o_owner_uid[sizeof("OBJECT_SYSTEMD_OWNER_UID=") + DECIMAL_STR_MAX(uid_t)];
+        uid_t object_uid;
+        gid_t object_gid;
+
+        char *x;
         sd_id128_t id;
         int r;
         char *t, *c;
         uid_t realuid = 0, owner = 0, journal_uid;
         bool owner_valid = false;
 #ifdef HAVE_AUDIT
-        char audit_session[sizeof("_AUDIT_SESSION=") + DECIMAL_STR_MAX(uint32_t)],
-                audit_loginuid[sizeof("_AUDIT_LOGINUID=") + DECIMAL_STR_MAX(uid_t)];
+        char    audit_session[sizeof("_AUDIT_SESSION=") + DECIMAL_STR_MAX(uint32_t)],
+                audit_loginuid[sizeof("_AUDIT_LOGINUID=") + DECIMAL_STR_MAX(uid_t)],
+                o_audit_session[sizeof("OBJECT_AUDIT_SESSION=") + DECIMAL_STR_MAX(uint32_t)],
+                o_audit_loginuid[sizeof("OBJECT_AUDIT_LOGINUID=") + DECIMAL_STR_MAX(uid_t)];
 
         uint32_t audit;
         uid_t loginuid;
@@ -525,7 +534,7 @@ static void dispatch_message_real(
         assert(s);
         assert(iovec);
         assert(n > 0);
-        assert(n + N_IOVEC_META_FIELDS <= m);
+        assert(n + N_IOVEC_META_FIELDS + (object_pid ? N_IOVEC_OBJECT_FIELDS : 0) <= m);
 
         if (ucred) {
                 realuid = ucred->uid;
@@ -541,23 +550,23 @@ static void dispatch_message_real(
 
                 r = get_process_comm(ucred->pid, &t);
                 if (r >= 0) {
-                        comm = strappenda("_COMM=", t);
+                        x = strappenda("_COMM=", t);
                         free(t);
-                        IOVEC_SET_STRING(iovec[n++], comm);
+                        IOVEC_SET_STRING(iovec[n++], x);
                 }
 
                 r = get_process_exe(ucred->pid, &t);
                 if (r >= 0) {
-                        exe = strappenda("_EXE=", t);
+                        x = strappenda("_EXE=", t);
                         free(t);
-                        IOVEC_SET_STRING(iovec[n++], exe);
+                        IOVEC_SET_STRING(iovec[n++], x);
                 }
 
                 r = get_process_cmdline(ucred->pid, 0, false, &t);
                 if (r >= 0) {
-                        cmdline = strappenda("_CMDLINE=", t);
+                        x = strappenda("_CMDLINE=", t);
                         free(t);
-                        IOVEC_SET_STRING(iovec[n++], cmdline);
+                        IOVEC_SET_STRING(iovec[n++], x);
                 }
 
 #ifdef HAVE_AUDIT
@@ -576,8 +585,10 @@ static void dispatch_message_real(
 
                 r = cg_pid_get_path_shifted(ucred->pid, NULL, &c);
                 if (r >= 0) {
-                        cgroup = strappenda("_SYSTEMD_CGROUP=", c);
-                        IOVEC_SET_STRING(iovec[n++], cgroup);
+                        char *session = NULL;
+
+                        x = strappenda("_SYSTEMD_CGROUP=", c);
+                        IOVEC_SET_STRING(iovec[n++], x);
 
                         r = cg_path_get_session(c, &t);
                         if (r >= 0) {
@@ -594,43 +605,126 @@ static void dispatch_message_real(
                         }
 
                         if (cg_path_get_unit(c, &t) >= 0) {
-                                unit = strappenda("_SYSTEMD_UNIT=", t);
+                                x = strappenda("_SYSTEMD_UNIT=", t);
                                 free(t);
                         } else if (cg_path_get_user_unit(c, &t) >= 0) {
-                                unit = strappenda("_SYSTEMD_USER_UNIT=", t);
+                                x = strappenda("_SYSTEMD_USER_UNIT=", t);
                                 free(t);
                         } else if (unit_id) {
                                 if (session)
-                                        unit = strappenda("_SYSTEMD_USER_UNIT=", unit_id);
+                                        x = strappenda("_SYSTEMD_USER_UNIT=", unit_id);
                                 else
-                                        unit = strappenda("_SYSTEMD_UNIT=", unit_id);
+                                        x = strappenda("_SYSTEMD_UNIT=", unit_id);
                         } else
-                                unit = NULL;
+                                x = NULL;
 
-                        if (unit)
-                                IOVEC_SET_STRING(iovec[n++], unit);
+                        if (x)
+                                IOVEC_SET_STRING(iovec[n++], x);
 
                         free(c);
                 }
 
 #ifdef HAVE_SELINUX
                 if (label) {
-                        char *selinux_context = alloca(sizeof("_SELINUX_CONTEXT=") + label_len);
+                        x = alloca(sizeof("_SELINUX_CONTEXT=") + label_len);
 
-                        *((char*) mempcpy(stpcpy(selinux_context, "_SELINUX_CONTEXT="), label, label_len)) = 0;
-                        IOVEC_SET_STRING(iovec[n++], selinux_context);
+                        *((char*) mempcpy(stpcpy(x, "_SELINUX_CONTEXT="), label, label_len)) = 0;
+                        IOVEC_SET_STRING(iovec[n++], x);
                 } else {
                         security_context_t con;
 
                         if (getpidcon(ucred->pid, &con) >= 0) {
-                                char *selinux_context = strappenda("_SELINUX_CONTEXT=", con);
+                                x = strappenda("_SELINUX_CONTEXT=", con);
 
                                 freecon(con);
-                                IOVEC_SET_STRING(iovec[n++], selinux_context);
+                                IOVEC_SET_STRING(iovec[n++], x);
                         }
                 }
 #endif
         }
+        assert(n <= m);
+
+        if (object_pid) {
+                r = get_process_uid(object_pid, &object_uid);
+                if (r >= 0) {
+                        sprintf(o_uid, "OBJECT_UID=%lu", (unsigned long) object_uid);
+                        IOVEC_SET_STRING(iovec[n++], o_uid);
+                }
+
+                r = get_process_gid(object_pid, &object_gid);
+                if (r >= 0) {
+                        sprintf(o_gid, "OBJECT_GID=%lu", (unsigned long) object_gid);
+                        IOVEC_SET_STRING(iovec[n++], o_gid);
+                }
+
+                r = get_process_comm(object_pid, &t);
+                if (r >= 0) {
+                        x = strappenda("OBJECT_COMM=", t);
+                        free(t);
+                        IOVEC_SET_STRING(iovec[n++], x);
+                }
+
+                r = get_process_exe(object_pid, &t);
+                if (r >= 0) {
+                        x = strappenda("OBJECT_EXE=", t);
+                        free(t);
+                        IOVEC_SET_STRING(iovec[n++], x);
+                }
+
+                r = get_process_cmdline(object_pid, 0, false, &t);
+                if (r >= 0) {
+                        x = strappenda("OBJECT_CMDLINE=", t);
+                        free(t);
+                        IOVEC_SET_STRING(iovec[n++], x);
+                }
+
+#ifdef HAVE_AUDIT
+                r = audit_session_from_pid(object_pid, &audit);
+                if (r >= 0) {
+                        sprintf(o_audit_session, "OBJECT_AUDIT_SESSION=%lu", (unsigned long) audit);
+                        IOVEC_SET_STRING(iovec[n++], o_audit_session);
+                }
+
+                r = audit_loginuid_from_pid(object_pid, &loginuid);
+                if (r >= 0) {
+                        sprintf(o_audit_loginuid, "OBJECT_AUDIT_LOGINUID=%lu", (unsigned long) loginuid);
+                        IOVEC_SET_STRING(iovec[n++], o_audit_loginuid);
+                }
+#endif
+
+                r = cg_pid_get_path_shifted(object_pid, NULL, &c);
+                if (r >= 0) {
+                        x = strappenda("OBJECT_SYSTEMD_CGROUP=", c);
+                        IOVEC_SET_STRING(iovec[n++], x);
+
+                        r = cg_path_get_session(c, &t);
+                        if (r >= 0) {
+                                x = strappenda("OBJECT_SYSTEMD_SESSION=", t);
+                                free(t);
+                                IOVEC_SET_STRING(iovec[n++], x);
+                        }
+
+                        if (cg_path_get_owner_uid(c, &owner) >= 0) {
+                                sprintf(o_owner_uid, "OBJECT_SYSTEMD_OWNER_UID=%lu", (unsigned long) owner);
+                                IOVEC_SET_STRING(iovec[n++], o_owner_uid);
+                        }
+
+                        if (cg_path_get_unit(c, &t) >= 0) {
+                                x = strappenda("OBJECT_SYSTEMD_UNIT=", t);
+                                free(t);
+                        } else if (cg_path_get_user_unit(c, &t) >= 0) {
+                                x = strappenda("OBJECT_SYSTEMD_USER_UNIT=", t);
+                                free(t);
+                        } else
+                                x = NULL;
+
+                        if (x)
+                                IOVEC_SET_STRING(iovec[n++], x);
+
+                        free(c);
+                }
+        }
+        assert(n <= m);
 
         if (tv) {
                 sprintf(source_time, "_SOURCE_REALTIME_TIMESTAMP=%llu", (unsigned long long) timeval_load(tv));
@@ -642,21 +736,21 @@ static void dispatch_message_real(
          * anyway. However, we need this indexed, too. */
         r = sd_id128_get_boot(&id);
         if (r >= 0) {
-                sd_id128_to_string(id, boot_id + sizeof("_BOOT_ID=") - 1);
+                sd_id128_to_string(id, boot_id + strlen("_BOOT_ID="));
                 IOVEC_SET_STRING(iovec[n++], boot_id);
         }
 
         r = sd_id128_get_machine(&id);
         if (r >= 0) {
-                sd_id128_to_string(id, machine_id + sizeof("_MACHINE_ID=") - 1);
+                sd_id128_to_string(id, machine_id + strlen("_MACHINE_ID="));
                 IOVEC_SET_STRING(iovec[n++], machine_id);
         }
 
         t = gethostname_malloc();
         if (t) {
-                hostname = strappenda("_HOSTNAME=", t);
+                x = strappenda("_HOSTNAME=", t);
                 free(t);
-                IOVEC_SET_STRING(iovec[n++], hostname);
+                IOVEC_SET_STRING(iovec[n++], x);
         }
 
         assert(n <= m);
@@ -709,7 +803,7 @@ void server_driver_message(Server *s, sd_id128_t message_id, const char *format,
         ucred.uid = getuid();
         ucred.gid = getgid();
 
-        dispatch_message_real(s, iovec, n, ELEMENTSOF(iovec), &ucred, NULL, NULL, 0, NULL);
+        dispatch_message_real(s, iovec, n, ELEMENTSOF(iovec), &ucred, NULL, NULL, 0, NULL, 0);
 }
 
 void server_dispatch_message(
@@ -719,7 +813,8 @@ void server_dispatch_message(
                 struct timeval *tv,
                 const char *label, size_t label_len,
                 const char *unit_id,
-                int priority) {
+                int priority,
+                pid_t object_pid) {
 
         int rl, r;
         _cleanup_free_ char *path = NULL;
@@ -769,7 +864,7 @@ void server_dispatch_message(
                                       "Suppressed %u messages from %s", rl - 1, path);
 
 finish:
-        dispatch_message_real(s, iovec, n, m, ucred, tv, label, label_len, unit_id);
+        dispatch_message_real(s, iovec, n, m, ucred, tv, label, label_len, unit_id, object_pid);
 }
 
 
diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
index 129f7e8ab..41f32ba68 100644
--- a/src/journal/journald-server.h
+++ b/src/journal/journald-server.h
@@ -128,8 +128,9 @@ typedef struct Server {
 #define N_IOVEC_META_FIELDS 17
 #define N_IOVEC_KERNEL_FIELDS 64
 #define N_IOVEC_UDEV_FIELDS 32
+#define N_IOVEC_OBJECT_FIELDS 11
 
-void server_dispatch_message(Server *s, struct iovec *iovec, unsigned n, unsigned m, struct ucred *ucred, struct timeval *tv, const char *label, size_t label_len, const char *unit_id, int priority);
+void server_dispatch_message(Server *s, struct iovec *iovec, unsigned n, unsigned m, struct ucred *ucred, struct timeval *tv, const char *label, size_t label_len, const char *unit_id, int priority, pid_t object_pid);
 void server_driver_message(Server *s, sd_id128_t message_id, const char *format, ...) _printf_attr_(3,4);
 
 /* gperf lookup function */
diff --git a/src/journal/journald-stream.c b/src/journal/journald-stream.c
index 3ce1c9ac4..e98fe94b4 100644
--- a/src/journal/journald-stream.c
+++ b/src/journal/journald-stream.c
@@ -127,7 +127,7 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
         }
 #endif
 
-        server_dispatch_message(s->server, iovec, n, ELEMENTSOF(iovec), &s->ucred, NULL, label, label_len, s->unit_id, priority);
+        server_dispatch_message(s->server, iovec, n, ELEMENTSOF(iovec), &s->ucred, NULL, label, label_len, s->unit_id, priority, 0);
 
         free(message);
         free(syslog_priority);
diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
index 4aeb9a35f..7cbb34608 100644
--- a/src/journal/journald-syslog.c
+++ b/src/journal/journald-syslog.c
@@ -400,7 +400,7 @@ void server_process_syslog_message(
         if (message)
                 IOVEC_SET_STRING(iovec[n++], message);
 
-        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), ucred, tv, label, label_len, NULL, priority);
+        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), ucred, tv, label, label_len, NULL, priority, 0);
 
         free(message);
         free(identifier);