chiark / gitweb /
journal: automaticall reset location when the set of matches changes
[elogind.git] / src / journal / sd-journal.c
index 8426b3bf9e232fe098f671ad3292bb8d10c13e3e..5d518a38709d07c2d1b9e7903f940a13838c90fb 100644 (file)
 
 #include <errno.h>
 #include <fcntl.h>
+#include <stddef.h>
 
 #include "sd-journal.h"
 #include "journal-def.h"
 #include "journal-file.h"
 #include "hashmap.h"
 #include "list.h"
+#include "lookup3.h"
 
 typedef struct Match Match;
 
 struct Match {
         char *data;
         size_t size;
-        uint64_t hash;
+        uint64_t le_hash;
 
         LIST_FIELDS(Match, matches);
 };
@@ -42,34 +44,55 @@ struct sd_journal {
         Hashmap *files;
 
         JournalFile *current_file;
+        uint64_t current_field;
 
         LIST_HEAD(Match, matches);
+        unsigned n_matches;
 };
 
-int sd_journal_add_match(sd_journal *j, const char *field, const void *data, size_t size) {
+static void reset_location(sd_journal *j) {
+        Iterator i;
+        JournalFile *f;
+
+        assert(j);
+
+        j->current_file = NULL;
+        j->current_field = 0;
+
+        HASHMAP_FOREACH(f, j->files, i)
+                f->current_offset = 0;
+}
+
+int sd_journal_add_match(sd_journal *j, const void *data, size_t size) {
         Match *m;
-        char *e;
 
         assert(j);
-        assert(field);
-        assert(data || size == 0);
+
+        if (size <= 0)
+                return -EINVAL;
+
+        assert(data);
 
         m = new0(Match, 1);
         if (!m)
                 return -ENOMEM;
 
-        m->size = strlen(field) + 1 + size;
+        m->size = size;
+
         m->data = malloc(m->size);
         if (!m->data) {
                 free(m);
                 return -ENOMEM;
         }
 
-        e = stpcpy(m->data, field);
-        *(e++) = '=';
-        memcpy(e, data, size);
+        memcpy(m->data, data, size);
+        m->le_hash = hash64(m->data, size);
 
         LIST_PREPEND(Match, matches, j->matches, m);
+        j->n_matches ++;
+
+        reset_location(j);
+
         return 0;
 }
 
@@ -83,13 +106,29 @@ void sd_journal_flush_matches(sd_journal *j) {
                 free(m->data);
                 free(m);
         }
+
+        j->n_matches = 0;
+
+        reset_location(j);
 }
 
 static int compare_order(JournalFile *af, Object *ao, uint64_t ap,
-                            JournalFile *bf, Object *bo, uint64_t bp) {
+                         JournalFile *bf, Object *bo, uint64_t bp) {
 
         uint64_t a, b;
 
+        /* We operate on two different files here, hence we can access
+         * two objects at the same time, which we normally can't.
+         *
+         * If contents and timestamps match, these entries are
+         * identical, even if the seqnum does not match */
+
+        if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id) &&
+            ao->entry.monotonic == bo->entry.monotonic &&
+            ao->entry.realtime == bo->entry.realtime &&
+            ao->entry.xor_hash == bo->entry.xor_hash)
+                return 0;
+
         if (sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id)) {
 
                 /* If this is from the same seqnum source, compare
@@ -97,68 +136,156 @@ static int compare_order(JournalFile *af, Object *ao, uint64_t ap,
                 a = le64toh(ao->entry.seqnum);
                 b = le64toh(bo->entry.seqnum);
 
+                if (a < b)
+                        return -1;
+                if (a > b)
+                        return 1;
+
+                /* Wow! This is weird, different data but the same
+                 * seqnums? Something is borked, but let's make the
+                 * best of it and compare by time. */
+        }
 
-        } else if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id)) {
+        if (sd_id128_equal(ao->entry.boot_id, bo->entry.boot_id)) {
 
                 /* If the boot id matches compare monotonic time */
                 a = le64toh(ao->entry.monotonic);
                 b = le64toh(bo->entry.monotonic);
 
-        } else {
-
-                /* Otherwise compare UTC time */
-                a = le64toh(ao->entry.realtime);
-                b = le64toh(ao->entry.realtime);
+                if (a < b)
+                        return -1;
+                if (a > b)
+                        return 1;
         }
 
-        return
-                a < b ? -1 :
-                a > b ? +1 : 0;
+        /* Otherwise compare UTC time */
+        a = le64toh(ao->entry.realtime);
+        b = le64toh(ao->entry.realtime);
+
+        if (a < b)
+                return -1;
+        if (a > b)
+                return 1;
+
+        /* Finally, compare by contents */
+        a = le64toh(ao->entry.xor_hash);
+        b = le64toh(ao->entry.xor_hash);
+
+        if (a < b)
+                return -1;
+        if (a > b)
+                return 1;
+
+        return 0;
 }
 
-int sd_journal_next(sd_journal *j) {
-        JournalFile *f, *new_current = NULL;
-        Iterator i;
+static int move_to_next_with_matches(sd_journal *j, JournalFile *f, direction_t direction, Object **o, uint64_t *p) {
         int r;
-        uint64_t new_offset = 0;
-        Object *new_entry = NULL;
+        uint64_t cp;
+        Object *c;
 
         assert(j);
+        assert(f);
+        assert(o);
+        assert(p);
 
-        HASHMAP_FOREACH(f, j->files, i) {
-                Object *o;
-                uint64_t p;
+        if (!j->matches) {
+                /* No matches is easy, just go on to the next entry */
 
                 if (f->current_offset > 0) {
-                        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+                        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &c);
                         if (r < 0)
                                 return r;
                 } else
-                        o = NULL;
+                        c = NULL;
 
-                r = journal_file_next_entry(f, o, &o, &p);
-                if (r < 0)
+                return journal_file_next_entry(f, c, direction, o, p);
+        }
+
+        /* So there are matches we have to adhere to, let's find the
+         * first entry that matches all of them */
+
+        if (f->current_offset > 0)
+                cp = f->current_offset;
+        else {
+                r = journal_file_find_first_entry(f, j->matches->data, j->matches->size, direction, &c, &cp);
+                if (r <= 0)
                         return r;
-                else if (r == 0)
-                        continue;
 
-                if (!new_current || compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
-                        new_current = f;
-                        new_entry = o;
-                        new_offset = p;
+                /* We can shortcut this if there's only one match */
+                if (j->n_matches == 1) {
+                        *o = c;
+                        *p = cp;
+                        return r;
                 }
         }
 
-        if (new_current) {
-                j->current_file = new_current;
-                f->current_offset = new_offset;
-                return 1;
-        }
+        for (;;) {
+                uint64_t np, n;
+                bool found;
+                Match *m;
 
-        return 0;
+                r = journal_file_move_to_object(f, cp, OBJECT_ENTRY, &c);
+                if (r < 0)
+                        return r;
+
+                n = journal_file_entry_n_items(c);
+
+                /* Make sure we don't match the entry we are starting
+                 * from. */
+                found = f->current_offset != cp;
+
+                np = 0;
+                LIST_FOREACH(matches, m, j->matches) {
+                        uint64_t q, k;
+
+                        for (k = 0; k < n; k++)
+                                if (c->entry.items[k].hash == m->le_hash)
+                                        break;
+
+                        if (k >= n) {
+                                /* Hmm, didn't find any field that matched, so ignore
+                                 * this match. Go on with next match */
+
+                                found = false;
+                                continue;
+                        }
+
+                        /* Hmm, so, this field matched, let's remember
+                         * where we'd have to try next, in case the other
+                         * matches are not OK */
+
+                        if (direction == DIRECTION_DOWN) {
+                                q = le64toh(c->entry.items[k].next_entry_offset);
+
+                                if (q > np)
+                                        np = q;
+                        } else {
+                                q = le64toh(c->entry.items[k].prev_entry_offset);
+
+                                if (q != 0 && (np == 0 || q < np))
+                                        np = q;
+                        }
+                }
+
+                /* Did this entry match against all matches? */
+                if (found) {
+                        *o = c;
+                        *p = cp;
+                        return 1;
+                }
+
+                /* Did we find a subsequent entry? */
+                if (np == 0)
+                        return 0;
+
+                /* Hmm, ok, this entry only matched partially, so
+                 * let's try another one */
+                cp = np;
+        }
 }
 
-int sd_journal_previous(sd_journal *j) {
+static int real_journal_next(sd_journal *j, direction_t direction) {
         JournalFile *f, *new_current = NULL;
         Iterator i;
         int r;
@@ -171,20 +298,14 @@ int sd_journal_previous(sd_journal *j) {
                 Object *o;
                 uint64_t p;
 
-                if (f->current_offset > 0) {
-                        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
-                        if (r < 0)
-                                return r;
-                } else
-                        o = NULL;
-
-                r = journal_file_prev_entry(f, o, &o, &p);
+                r = move_to_next_with_matches(j, f, direction, &o, &p);
                 if (r < 0)
                         return r;
                 else if (r == 0)
                         continue;
 
-                if (!new_current || compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
+                if (!new_current ||
+                    compare_order(new_current, new_entry, new_offset, f, o, p) > 0) {
                         new_current = f;
                         new_entry = o;
                         new_offset = p;
@@ -193,59 +314,162 @@ int sd_journal_previous(sd_journal *j) {
 
         if (new_current) {
                 j->current_file = new_current;
-                f->current_offset = new_offset;
+                j->current_file->current_offset = new_offset;
+                j->current_field = 0;
+
+                /* Skip over any identical entries in the other files too */
+
+                HASHMAP_FOREACH(f, j->files, i) {
+                        Object *o;
+                        uint64_t p;
+
+                        if (j->current_file == f)
+                                continue;
+
+                        r = move_to_next_with_matches(j, f, direction, &o, &p);
+                        if (r < 0)
+                                return r;
+                        else if (r == 0)
+                                continue;
+
+                        if (compare_order(new_current, new_entry, new_offset, f, o, p) == 0)
+                                f->current_offset = p;
+                }
+
                 return 1;
         }
 
         return 0;
 }
 
-int sd_journal_get_cursor(sd_journal *j, void **cursor, size_t *size) {
-        JournalCursor *c;
+int sd_journal_next(sd_journal *j) {
+        return real_journal_next(j, DIRECTION_DOWN);
+}
+
+int sd_journal_previous(sd_journal *j) {
+        return real_journal_next(j, DIRECTION_UP);
+}
+
+int sd_journal_get_cursor(sd_journal *j, char **cursor) {
         Object *o;
         int r;
+        char bid[33], sid[33];
 
         assert(j);
         assert(cursor);
-        assert(size);
 
-        if (!j->current_file || !j->current_file->current_offset <= 0)
-                return 0;
+        if (!j->current_file || j->current_file->current_offset <= 0)
+                return -EADDRNOTAVAIL;
 
         r = journal_file_move_to_object(j->current_file, j->current_file->current_offset, OBJECT_ENTRY, &o);
         if (r < 0)
                 return r;
 
-        c = new0(JournalCursor, 1);
-        if (!c)
-                return -ENOMEM;
-
-        c->version = 1;
-        c->seqnum = o->entry.seqnum;
-        c->seqnum_id = j->current_file->header->seqnum_id;
-        c->boot_id = o->entry.boot_id;
-        c->monotonic = o->entry.monotonic;
-        c->realtime = o->entry.realtime;
-        c->xor_hash = o->entry.xor_hash;
+        sd_id128_to_string(j->current_file->header->seqnum_id, sid);
+        sd_id128_to_string(o->entry.boot_id, bid);
 
-        *cursor = c;
-        *size = sizeof(JournalCursor);
+        if (asprintf(cursor,
+                     "s=%s;i=%llx;b=%s;m=%llx;t=%llx;x=%llx;p=%s",
+                     sid, (unsigned long long) le64toh(o->entry.seqnum),
+                     bid, (unsigned long long) le64toh(o->entry.monotonic),
+                     (unsigned long long) le64toh(o->entry.realtime),
+                     (unsigned long long) le64toh(o->entry.xor_hash),
+                     file_name_from_path(j->current_file->path)) < 0)
+                return -ENOMEM;
 
         return 1;
 }
 
-int sd_journal_set_cursor(sd_journal *j, const void *cursor, size_t size) {
+int sd_journal_set_cursor(sd_journal *j, const char *cursor) {
         return -EINVAL;
 }
 
+static int add_file(sd_journal *j, const char *prefix, const char *dir, const char *filename) {
+        char *fn;
+        int r;
+        JournalFile *f;
+
+        assert(j);
+        assert(prefix);
+        assert(filename);
+
+        if (dir)
+                fn = join(prefix, "/", dir, "/", filename, NULL);
+        else
+                fn = join(prefix, "/", filename, NULL);
+
+        if (!fn)
+                return -ENOMEM;
+
+        r = journal_file_open(fn, O_RDONLY, 0, NULL, &f);
+        free(fn);
+
+        if (r < 0) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return r;
+        }
+
+        r = hashmap_put(j->files, f->path, f);
+        if (r < 0) {
+                journal_file_close(f);
+                return r;
+        }
+
+        return 0;
+}
+
+static int add_directory(sd_journal *j, const char *prefix, const char *dir) {
+        char *fn;
+        int r;
+        DIR *d;
+
+        assert(j);
+        assert(prefix);
+        assert(dir);
+
+        fn = join(prefix, "/", dir, NULL);
+        if (!fn)
+                return -ENOMEM;
+
+        d = opendir(fn);
+        free(fn);
+
+        if (!d) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return -errno;
+        }
+
+        for (;;) {
+                struct dirent buf, *de;
+
+                r = readdir_r(d, &buf, &de);
+                if (r != 0 || !de)
+                        break;
+
+                if (!dirent_is_file_with_suffix(de, ".journal"))
+                        continue;
+
+                r = add_file(j, prefix, dir, de->d_name);
+                if (r < 0)
+                        log_debug("Failed to add file %s/%s/%s: %s", prefix, dir, de->d_name, strerror(-r));
+        }
+
+        closedir(d);
+
+        return 0;
+}
+
 int sd_journal_open(sd_journal **ret) {
         sd_journal *j;
-        char *fn;
         const char *p;
-        int r = 0;
         const char search_paths[] =
                 "/run/log/journal\0"
                 "/var/log/journal\0";
+        int r;
 
         assert(ret);
 
@@ -254,64 +478,47 @@ int sd_journal_open(sd_journal **ret) {
                 return -ENOMEM;
 
         j->files = hashmap_new(string_hash_func, string_compare_func);
-        if (!j->files)
+        if (!j->files) {
+                r = -ENOMEM;
                 goto fail;
+        }
+
+        /* We ignore most errors here, since the idea is to only open
+         * what's actually accessible, and ignore the rest. */
 
         NULSTR_FOREACH(p, search_paths) {
                 DIR *d;
 
                 d = opendir(p);
                 if (!d) {
-                        if (errno != ENOENT && r == 0)
-                                r = -errno;
-
+                        if (errno != ENOENT)
+                                log_debug("Failed to open %s: %m", p);
                         continue;
                 }
 
                 for (;;) {
                         struct dirent buf, *de;
-                        int k;
-                        JournalFile *f;
-
-                        k = readdir_r(d, &buf, &de);
-                        if (k != 0) {
-                                if (r == 0)
-                                        r = -k;
-
-                                break;
-                        }
+                        sd_id128_t id;
 
-                        if (!de)
+                        r = readdir_r(d, &buf, &de);
+                        if (r != 0 || !de)
                                 break;
 
-                        if (!dirent_is_file_with_suffix(de, ".journal"))
-                                continue;
-
-                        fn = join(p, "/", de->d_name, NULL);
-                        if (!fn) {
-                                r = -ENOMEM;
-                                closedir(d);
-                                goto fail;
-                        }
-
-                        k = journal_file_open(fn, O_RDONLY, 0, &f);
-                        free(fn);
+                        if (dirent_is_file_with_suffix(de, ".journal")) {
+                                r = add_file(j, p, NULL, de->d_name);
+                                if (r < 0)
+                                        log_debug("Failed to add file %s/%s: %s", p, de->d_name, strerror(-r));
 
-                        if (k < 0) {
+                        } else if ((de->d_type == DT_DIR || de->d_type == DT_UNKNOWN) &&
+                                   sd_id128_from_string(de->d_name, &id) >= 0) {
 
-                                if (r == 0)
-                                        r = -k;
-                        } else {
-                                k = hashmap_put(j->files, f->path, f);
-                                if (k < 0) {
-                                        journal_file_close(f);
-                                        closedir(d);
-
-                                        r = k;
-                                        goto fail;
-                                }
+                                r = add_directory(j, p, de->d_name);
+                                if (r < 0)
+                                        log_debug("Failed to add directory %s/%s: %s", p, de->d_name, strerror(-r));
                         }
                 }
+
+                closedir(d);
         }
 
         *ret = j;
@@ -335,5 +542,201 @@ void sd_journal_close(sd_journal *j) {
                 hashmap_free(j->files);
         }
 
+        sd_journal_flush_matches(j);
+
         free(j);
 }
+
+int sd_journal_get_realtime_usec(sd_journal *j, uint64_t *ret) {
+        Object *o;
+        JournalFile *f;
+        int r;
+
+        assert(j);
+        assert(ret);
+
+        f = j->current_file;
+        if (!f)
+                return 0;
+
+        if (f->current_offset <= 0)
+                return 0;
+
+        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+        if (r < 0)
+                return r;
+
+        *ret = le64toh(o->entry.realtime);
+        return 1;
+}
+
+int sd_journal_get_monotonic_usec(sd_journal *j, uint64_t *ret) {
+        Object *o;
+        JournalFile *f;
+        int r;
+        sd_id128_t id;
+
+        assert(j);
+        assert(ret);
+
+        f = j->current_file;
+        if (!f)
+                return 0;
+
+        if (f->current_offset <= 0)
+                return 0;
+
+        r = sd_id128_get_boot(&id);
+        if (r < 0)
+                return r;
+
+        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+        if (r < 0)
+                return r;
+
+        if (!sd_id128_equal(id, o->entry.boot_id))
+                return 0;
+
+        *ret = le64toh(o->entry.monotonic);
+        return 1;
+
+}
+
+int sd_journal_get_data(sd_journal *j, const char *field, const void **data, size_t *size) {
+        JournalFile *f;
+        uint64_t i, n;
+        size_t field_length;
+        int r;
+        Object *o;
+
+        assert(j);
+        assert(field);
+        assert(data);
+        assert(size);
+
+        if (isempty(field) || strchr(field, '='))
+                return -EINVAL;
+
+        f = j->current_file;
+        if (!f)
+                return 0;
+
+        if (f->current_offset <= 0)
+                return 0;
+
+        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+        if (r < 0)
+                return r;
+
+        field_length = strlen(field);
+
+        n = journal_file_entry_n_items(o);
+        for (i = 0; i < n; i++) {
+                uint64_t p, l, h;
+                size_t t;
+
+                p = le64toh(o->entry.items[i].object_offset);
+                h = o->entry.items[j->current_field].hash;
+                r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
+                if (r < 0)
+                        return r;
+
+                if (h != o->data.hash)
+                        return -EBADMSG;
+
+                l = le64toh(o->object.size) - offsetof(Object, data.payload);
+
+                if (l >= field_length+1 &&
+                    memcmp(o->data.payload, field, field_length) == 0 &&
+                    o->data.payload[field_length] == '=') {
+
+                        t = (size_t) l;
+
+                        if ((uint64_t) t != l)
+                                return -E2BIG;
+
+                        *data = o->data.payload;
+                        *size = t;
+
+                        return 1;
+                }
+
+                r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int sd_journal_enumerate_data(sd_journal *j, const void **data, size_t *size) {
+        JournalFile *f;
+        uint64_t p, l, n, h;
+        size_t t;
+        int r;
+        Object *o;
+
+        assert(j);
+        assert(data);
+        assert(size);
+
+        f = j->current_file;
+        if (!f)
+                return 0;
+
+        if (f->current_offset <= 0)
+                return 0;
+
+        r = journal_file_move_to_object(f, f->current_offset, OBJECT_ENTRY, &o);
+        if (r < 0)
+                return r;
+
+        n = journal_file_entry_n_items(o);
+        if (j->current_field >= n)
+                return 0;
+
+        p = le64toh(o->entry.items[j->current_field].object_offset);
+        h = o->entry.items[j->current_field].hash;
+        r = journal_file_move_to_object(f, p, OBJECT_DATA, &o);
+        if (r < 0)
+                return r;
+
+        if (h != o->data.hash)
+                return -EBADMSG;
+
+        l = le64toh(o->object.size) - offsetof(Object, data.payload);
+        t = (size_t) l;
+
+        /* We can't read objects larger than 4G on a 32bit machine */
+        if ((uint64_t) t != l)
+                return -E2BIG;
+
+        *data = o->data.payload;
+        *size = t;
+
+        j->current_field ++;
+
+        return 1;
+}
+
+void sd_journal_start_data(sd_journal *j) {
+        assert(j);
+
+        j->current_field = 0;
+}
+
+int sd_journal_seek_head(sd_journal *j) {
+        assert(j);
+
+        reset_location(j);
+
+        return real_journal_next(j, DIRECTION_DOWN);
+}
+
+int sd_journal_seek_tail(sd_journal *j) {
+        assert(j);
+
+        reset_location(j);
+
+        return real_journal_next(j, DIRECTION_UP);
+}