journalctl: move access_check() to shared/

The only functional change is that log_notice("No journal files were found.")
is not printed any more with --quiet. log_error("No journal files were opened
due to insufficient permissions.") is still printed.

I wasn't quite sure where to put this function, but shared/ seems to be the
right place and none of the existing files seem to fit too well.

v2: rename journal_access_check to journal_access_check_and_warn.

2 files changed, 176 insertions, 0 deletions

diff --git a/src/shared/journal-util.c b/src/shared/journal-util.c
new file mode 100644
index 0000000000..8479221a44
--- /dev/null
+++ b/src/shared/journal-util.c
@@ -0,0 +1,151 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Zbigniew Jędrzejewski-Szmek
+  Copyright 2015 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 "acl-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "journal-internal.h"
+#include "journal-util.h"
+#include "log.h"
+#include "strv.h"
+#include "user-util.h"
+
+static int access_check_var_log_journal(sd_journal *j) {
+#ifdef HAVE_ACL
+        _cleanup_strv_free_ char **g = NULL;
+        const char* dir;
+#endif
+        int r;
+
+        assert(j);
+
+        /* If we are root, we should have access, don't warn. */
+        if (getuid() == 0)
+                return 0;
+
+        /* If we are in the 'systemd-journal' group, we should have
+         * access too. */
+        r = in_group("systemd-journal");
+        if (r < 0)
+                return log_error_errno(r, "Failed to check if we are in the 'systemd-journal' group: %m");
+        if (r > 0)
+                return 0;
+
+#ifdef HAVE_ACL
+        if (laccess("/run/log/journal", F_OK) >= 0)
+                dir = "/run/log/journal";
+        else
+                dir = "/var/log/journal";
+
+        /* If we are in any of the groups listed in the journal ACLs,
+         * then all is good, too. Let's enumerate all groups from the
+         * default ACL of the directory, which generally should allow
+         * access to most journal files too. */
+        r = acl_search_groups(dir, &g);
+        if (r < 0)
+                return log_error_errno(r, "Failed to search journal ACL: %m");
+        if (r > 0)
+                return 0;
+
+        /* Print a pretty list, if there were ACLs set. */
+        if (!strv_isempty(g)) {
+                _cleanup_free_ char *s = NULL;
+
+                /* Thre are groups in the ACL, let's list them */
+                r = strv_extend(&g, "systemd-journal");
+                if (r < 0)
+                        return log_oom();
+
+                strv_sort(g);
+                strv_uniq(g);
+
+                s = strv_join(g, "', '");
+                if (!s)
+                        return log_oom();
+
+                log_notice("Hint: You are currently not seeing messages from other users and the system.\n"
+                           "      Users in groups '%s' can see all messages.\n"
+                           "      Pass -q to turn off this notice.", s);
+                return 1;
+        }
+#endif
+
+        /* If no ACLs were found, print a short version of the message. */
+        log_notice("Hint: You are currently not seeing messages from other users and the system.\n"
+                   "      Users in the 'systemd-journal' group can see all messages. Pass -q to\n"
+                   "      turn off this notice.");
+
+        return 1;
+}
+
+int journal_access_check_and_warn(sd_journal *j, bool quiet) {
+        Iterator it;
+        void *code;
+        char *path;
+        int r = 0;
+
+        assert(j);
+
+        if (hashmap_isempty(j->errors)) {
+                if (ordered_hashmap_isempty(j->files) && !quiet)
+                        log_notice("No journal files were found.");
+
+                return 0;
+        }
+
+        if (hashmap_contains(j->errors, INT_TO_PTR(-EACCES))) {
+                if (!quiet)
+                        (void) access_check_var_log_journal(j);
+
+                if (ordered_hashmap_isempty(j->files))
+                        r = log_error_errno(EACCES, "No journal files were opened due to insufficient permissions.");
+        }
+
+        HASHMAP_FOREACH_KEY(path, code, j->errors, it) {
+                int err;
+
+                err = abs(PTR_TO_INT(code));
+
+                switch (err) {
+                case EACCES:
+                        continue;
+
+                case ENODATA:
+                        log_warning_errno(err, "Journal file %s is truncated, ignoring file.", path);
+                        break;
+
+                case EPROTONOSUPPORT:
+                        log_warning_errno(err, "Journal file %1$s uses an unsupported feature, ignoring file.\n"
+                                               "Use SYSTEMD_LOG_LEVEL=debug journalctl --file=%1$s to see the details.",
+                                               path);
+                        break;
+
+                case EBADMSG:
+                        log_warning_errno(err, "Journal file %s corrupted, ignoring file.", path);
+                        break;
+
+                default:
+                        log_warning_errno(err, "An error was encountered while opening journal file or directory %s, ignoring file: %m", path);
+                        break;
+                }
+        }
+
+        return r;
+}
diff --git a/src/shared/journal-util.h b/src/shared/journal-util.h
new file mode 100644
index 0000000000..499e6c62ec
--- /dev/null
+++ b/src/shared/journal-util.h
@@ -0,0 +1,25 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Zbigniew Jędrzejewski-Szmek
+  Copyright 2015 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 <stdbool.h>
+
+#include "sd-journal.h"
+
+int journal_access_check_and_warn(sd_journal *j, bool quiet);