journal: add ability to filter by current user

This is the just the library part.

SD_JOURNAL_CURRENT_USER flags is added to sd_j_open(), to open
files from current user.

SD_JOURNAL_SYSTEM_ONLY is renamed to SD_JOURNAL_SYSTEM,
and changed to mean to (also) open system files. This way various
flags can be combined, which gives them nicer semantics, especially
if other ones are added later.

Backwards compatibility is kept, because SD_JOURNAL_SYSTEM_ONLY
is equivalent to SD_JOURNAL_SYSTEM if used alone, and before there
we no other flags.

7 files changed, 85 insertions, 14 deletions

diff --git a/Makefile-man.am b/Makefile-man.am
index 58881586cf..a31427e9b9 100644
--- a/Makefile-man.am
+++ b/Makefile-man.am
@@ -107,6 +107,7 @@ MANPAGES_ALIAS += \
 	man/SD_ID128_MAKE.3 \
 	man/SD_INFO.3 \
 	man/SD_JOURNAL_APPEND.3 \
+	man/SD_JOURNAL_CURRENT_USER.3 \
 	man/SD_JOURNAL_FOREACH.3 \
 	man/SD_JOURNAL_FOREACH_BACKWARDS.3 \
 	man/SD_JOURNAL_FOREACH_DATA.3 \
@@ -116,6 +117,7 @@ MANPAGES_ALIAS += \
 	man/SD_JOURNAL_NOP.3 \
 	man/SD_JOURNAL_RUNTIME_ONLY.3 \
 	man/SD_JOURNAL_SUPPRESS_LOCATION.3 \
+	man/SD_JOURNAL_SYSTEM.3 \
 	man/SD_JOURNAL_SYSTEM_ONLY.3 \
 	man/SD_LISTEN_FDS_START.3 \
 	man/SD_NOTICE.3 \
@@ -205,6 +207,7 @@ man/SD_ID128_FORMAT_VAL.3: man/sd-id128.3
 man/SD_ID128_MAKE.3: man/sd-id128.3
 man/SD_INFO.3: man/sd-daemon.3
 man/SD_JOURNAL_APPEND.3: man/sd_journal_get_fd.3
+man/SD_JOURNAL_CURRENT_USER.3: man/sd_journal_open.3
 man/SD_JOURNAL_FOREACH.3: man/sd_journal_next.3
 man/SD_JOURNAL_FOREACH_BACKWARDS.3: man/sd_journal_next.3
 man/SD_JOURNAL_FOREACH_DATA.3: man/sd_journal_get_data.3
@@ -214,6 +217,7 @@ man/SD_JOURNAL_LOCAL_ONLY.3: man/sd_journal_open.3
 man/SD_JOURNAL_NOP.3: man/sd_journal_get_fd.3
 man/SD_JOURNAL_RUNTIME_ONLY.3: man/sd_journal_open.3
 man/SD_JOURNAL_SUPPRESS_LOCATION.3: man/sd_journal_print.3
+man/SD_JOURNAL_SYSTEM.3: man/sd_journal_open.3
 man/SD_JOURNAL_SYSTEM_ONLY.3: man/sd_journal_open.3
 man/SD_LISTEN_FDS_START.3: man/sd_listen_fds.3
 man/SD_NOTICE.3: man/sd-daemon.3
@@ -325,6 +329,9 @@ man/SD_INFO.html: man/sd-daemon.html
 man/SD_JOURNAL_APPEND.html: man/sd_journal_get_fd.html
 	$(html-alias)
 
+man/SD_JOURNAL_CURRENT_USER.html: man/sd_journal_open.html
+	$(html-alias)
+
 man/SD_JOURNAL_FOREACH.html: man/sd_journal_next.html
 	$(html-alias)
 
@@ -352,6 +359,9 @@ man/SD_JOURNAL_RUNTIME_ONLY.html: man/sd_journal_open.html
 man/SD_JOURNAL_SUPPRESS_LOCATION.html: man/sd_journal_print.html
 	$(html-alias)
 
+man/SD_JOURNAL_SYSTEM.html: man/sd_journal_open.html
+	$(html-alias)
+
 man/SD_JOURNAL_SYSTEM_ONLY.html: man/sd_journal_open.html
 	$(html-alias)
 
diff --git a/man/sd_journal_open.xml b/man/sd_journal_open.xml
index 76b857b991..dd2f32d81a 100644
--- a/man/sd_journal_open.xml
+++ b/man/sd_journal_open.xml
@@ -49,7 +49,8 @@
                 <refname>sd_journal</refname>
                 <refname>SD_JOURNAL_LOCAL_ONLY</refname>
                 <refname>SD_JOURNAL_RUNTIME_ONLY</refname>
-                <refname>SD_JOURNAL_SYSTEM_ONLY</refname>
+                <refname>SD_JOURNAL_SYSTEM</refname>
+                <refname>SD_JOURNAL_CURRENT_USER</refname>
                 <refpurpose>Open the system journal for reading</refpurpose>
         </refnamediv>
 
@@ -93,10 +94,14 @@
                 be opened. <literal>SD_JOURNAL_RUNTIME_ONLY</literal>
                 makes sure only volatile journal files will be opened,
                 excluding those which are stored on persistent
-                storage. <literal>SD_JOURNAL_SYSTEM_ONLY</literal>
-                will ensure that only journal files of system services
-                and the kernel (in opposition to user session processes) will
-                be opened.</para>
+                storage. <literal>SD_JOURNAL_SYSTEM</literal>
+                will cause journal files of system services and the
+                kernel (in opposition to user session processes) to
+                be opened. <literal>SD_JOURNAL_CURRENT_USER</literal>
+                will cause journal files of the current user to be
+                opened. If neither <literal>SD_JOURNAL_SYSTEM</literal>
+                nor <literal>SD_JOURNAL_CURRENT_USER</literal> are
+                specified, all journal file types will be opened.</para>
 
                 <para><function>sd_journal_open_directory()</function>
                 is similar to <function>sd_journal_open()</function>
@@ -171,6 +176,26 @@
         </refsect1>
 
         <refsect1>
+                <title>History</title>
+
+                <para><function>sd_journal_open()</function>,
+                <function>sd_journal_close()</function>,
+                <literal>SD_JOURNAL_LOCAL_ONLY</literal>,
+                <literal>SD_JOURNAL_RUNTIME_ONLY</literal>,
+                <literal>SD_JOURNAL_SYSTEM_ONLY</literal> were added
+                in systemd-38.</para>
+
+                <para><function>sd_journal_open_directory()</function>
+                was added in systemd-187.</para>
+
+                <para><literal>SD_JOURNAL_SYSTEM</literal> and
+                <literal>SD_JOURNAL_CURRENT_USER</literal> were added
+                in systemd-205.
+                <literal>SD_JOURNAL_SYSTEM_ONLY</literal>
+                was deprecated.</para>
+        </refsect1>
+
+        <refsect1>
                 <title>See Also</title>
 
                 <para>
diff --git a/src/journal/journal-gatewayd.c b/src/journal/journal-gatewayd.c
index 745f45f932..86338c66f3 100644
--- a/src/journal/journal-gatewayd.c
+++ b/src/journal/journal-gatewayd.c
@@ -109,7 +109,7 @@ static int open_journal(RequestMeta *m) {
         if (m->journal)
                 return 0;
 
-        return sd_journal_open(&m->journal, SD_JOURNAL_LOCAL_ONLY|SD_JOURNAL_SYSTEM_ONLY);
+        return sd_journal_open(&m->journal, SD_JOURNAL_LOCAL_ONLY|SD_JOURNAL_SYSTEM);
 }
 
 static int respond_oom_internal(struct MHD_Connection *connection) {
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index 2bad243ea1..46511df6be 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -1249,6 +1249,42 @@ static void check_network(sd_journal *j, int fd) {
                 F_TYPE_CMP(sfs.f_type, SMB_SUPER_MAGIC);
 }
 
+static bool file_has_type_prefix(const char *prefix, const char *filename) {
+        const char *full, *tilded, *atted;
+
+        full = strappend(prefix, ".journal");
+        tilded = strappenda(full, "~");
+        atted = strappenda(prefix, "@");
+
+        return streq(filename, full) ||
+               streq(filename, tilded) ||
+               startswith(filename, atted);
+}
+
+static bool file_type_wanted(int flags, const char *filename) {
+        if (!endswith(filename, ".journal") && !endswith(filename, ".journal~"))
+                return false;
+
+        /* no flags set → every type is OK */
+        if (!(flags & (SD_JOURNAL_SYSTEM | SD_JOURNAL_CURRENT_USER)))
+                return true;
+
+        if (flags & SD_JOURNAL_SYSTEM && file_has_type_prefix("system", filename))
+                return true;
+
+        if (flags & SD_JOURNAL_CURRENT_USER) {
+                char prefix[5 + DECIMAL_STR_MAX(uid_t) + 1];
+
+                assert_se(snprintf(prefix, sizeof(prefix), "user-%lu", (unsigned long) getuid())
+                          < (int) sizeof(prefix));
+
+                if (file_has_type_prefix(prefix, filename))
+                        return true;
+        }
+
+        return false;
+}
+
 static int add_file(sd_journal *j, const char *prefix, const char *filename) {
         _cleanup_free_ char *path = NULL;
         int r;
@@ -1258,11 +1294,7 @@ static int add_file(sd_journal *j, const char *prefix, const char *filename) {
         assert(prefix);
         assert(filename);
 
-        if ((j->flags & SD_JOURNAL_SYSTEM_ONLY) &&
-            !(streq(filename, "system.journal") ||
-              streq(filename, "system.journal~") ||
-              (startswith(filename, "system@") &&
-               (endswith(filename, ".journal") || endswith(filename, ".journal~")))))
+        if (!file_type_wanted(j->flags, filename))
                 return 0;
 
         path = strjoin(prefix, "/", filename, NULL);
@@ -1619,7 +1651,8 @@ _public_ int sd_journal_open(sd_journal **ret, int flags) {
 
         if (flags & ~(SD_JOURNAL_LOCAL_ONLY|
                       SD_JOURNAL_RUNTIME_ONLY|
-                      SD_JOURNAL_SYSTEM_ONLY))
+                      SD_JOURNAL_SYSTEM|
+                      SD_JOURNAL_CURRENT_USER))
                 return -EINVAL;
 
         j = journal_new(flags, NULL);
diff --git a/src/python-systemd/_reader.c b/src/python-systemd/_reader.c
index c4c4fdfe1d..2c699630c2 100644
--- a/src/python-systemd/_reader.c
+++ b/src/python-systemd/_reader.c
@@ -1097,6 +1097,7 @@ init_reader(void)
         PyModule_AddIntConstant(m, "INVALIDATE", SD_JOURNAL_INVALIDATE) ||
         PyModule_AddIntConstant(m, "LOCAL_ONLY", SD_JOURNAL_LOCAL_ONLY) ||
         PyModule_AddIntConstant(m, "RUNTIME_ONLY", SD_JOURNAL_RUNTIME_ONLY) ||
+        PyModule_AddIntConstant(m, "SYSTEM", SD_JOURNAL_SYSTEM) ||
         PyModule_AddIntConstant(m, "SYSTEM_ONLY", SD_JOURNAL_SYSTEM_ONLY) ||
         PyModule_AddStringConstant(m, "__version__", PACKAGE_VERSION)) {
 #if PY_MAJOR_VERSION >= 3
diff --git a/src/shared/logs-show.c b/src/shared/logs-show.c
index 7947df3a89..013a281eac 100644
--- a/src/shared/logs-show.c
+++ b/src/shared/logs-show.c
@@ -1010,7 +1010,7 @@ int show_journal_by_unit(
 
         _cleanup_journal_close_ sd_journal*j = NULL;
         int r;
-        int jflags = SD_JOURNAL_LOCAL_ONLY | system * SD_JOURNAL_SYSTEM_ONLY;
+        int jflags = SD_JOURNAL_LOCAL_ONLY | system * SD_JOURNAL_SYSTEM;
 
         assert(mode >= 0);
         assert(mode < _OUTPUT_MODE_MAX);
diff --git a/src/systemd/sd-journal.h b/src/systemd/sd-journal.h
index 5375d49963..cf105cde72 100644
--- a/src/systemd/sd-journal.h
+++ b/src/systemd/sd-journal.h
@@ -86,7 +86,9 @@ typedef struct sd_journal sd_journal;
 enum {
         SD_JOURNAL_LOCAL_ONLY = 1,
         SD_JOURNAL_RUNTIME_ONLY = 2,
-        SD_JOURNAL_SYSTEM_ONLY = 4
+        SD_JOURNAL_SYSTEM = 4,
+        SD_JOURNAL_SYSTEM_ONLY = SD_JOURNAL_SYSTEM, /* deprecated */
+        SD_JOURNAL_CURRENT_USER = 8,
 };
 
 /* Wakeup event types */