diff --git a/man/journald.conf.xml b/man/journald.conf.xml
index e4dc5862d9..8974f8f8d5 100644
--- a/man/journald.conf.xml
+++ b/man/journald.conf.xml
@@ -373,6 +373,24 @@
/dev/console.
+
+ LineMax=
+
+ The maximum line length to permit when converting stream logs into record logs. When a systemd
+ unit's standard output/error are connected to the journal via a stream socket, the data read is split into
+ individual log records at newline (\n, ASCII 10) and NUL characters. If no such delimiter is
+ read for the specified number of bytes a hard log record boundary is artifically inserted, breaking up overly
+ long lines into multiple log records. Selecting overly large values increases the possible memory usage of the
+ Journal daemon for each stream client, as in the worst case the journal daemon needs to buffer the specified
+ number of bytes in memory before it can flush a new log record to disk. Also note that permitting overly large
+ line maximum line lengths affects compatibility with traditional log protocols as log records might not fit
+ anymore into a single AF_UNIX or AF_INET datagram. Takes a size in
+ bytes. If the value is suffixed with K, M, G or T, the specified size is parsed as Kilobytes, Megabytes,
+ Gigabytes, or Terabytes (with the base 1024), respectively. Defaults to 48K, which is relatively large but
+ still small enough so that log records likely fit into network datagrams along with extra room for
+ metadata. Note that values below 79 are not accepted and will be bumped to 79.
+
+
diff --git a/man/systemd-journald.service.xml b/man/systemd-journald.service.xml
index 559ef1090a..fec0e1fe88 100644
--- a/man/systemd-journald.service.xml
+++ b/man/systemd-journald.service.xml
@@ -149,8 +149,9 @@ systemd-tmpfiles --create --prefix /var/log/journal
via the systemd-cat1 command
line tool.
- Currently, the number of parallel log streams systemd-journald will accept is limited
- to 4096.
+ Currently, the number of parallel log streams systemd-journald will accept is limited to
+ 4096. When this limit is reached further log streams may be established but will receieve
+ EPIPE right from the beginning.
diff --git a/man/systemd.journal-fields.xml b/man/systemd.journal-fields.xml
index b82c1300ca..e488affe3e 100644
--- a/man/systemd.journal-fields.xml
+++ b/man/systemd.journal-fields.xml
@@ -333,6 +333,28 @@
+
+ _STREAM_ID=
+
+ Only applies to _TRANSPORT=stream records: specifies a randomized 128bit ID assigned
+ to the stream connection when it was first created. This ID is useful to reconstruct individual log streams
+ from the log records: all log records carrying the same stream ID originate from the same stream.
+
+
+
+ _LINE_BREAK=
+
+ Only applies to _TRANSPORT=stream records: indicates that the log message in the
+ standard output/error stream was not terminated with a normal newline character (\n,
+ i.e. ASCII 10). Specifically, when set this field is one of (in case the line was
+ terminated by a NUL byte), (in case the maximum log line length was reached, as
+ configured with LineMax= in
+ journald.conf5) or
+ (if this was the last log record of a stream and the stream ended without a final
+ newline character). Note that this record is not generated when a normal newline character was used for
+ marking the log line end.
+
+
diff --git a/src/journal/journald-gperf.gperf b/src/journal/journald-gperf.gperf
index 522ad30cf3..6b05bda0ae 100644
--- a/src/journal/journald-gperf.gperf
+++ b/src/journal/journald-gperf.gperf
@@ -45,3 +45,4 @@ Journal.MaxLevelKMsg, config_parse_log_level, 0, offsetof(Server, max_lev
Journal.MaxLevelConsole, config_parse_log_level, 0, offsetof(Server, max_level_console)
Journal.MaxLevelWall, config_parse_log_level, 0, offsetof(Server, max_level_wall)
Journal.SplitMode, config_parse_split_mode, 0, offsetof(Server, split_mode)
+Journal.LineMax, config_parse_line_max, 0, offsetof(Server, line_max)
diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index feef10c2db..27c2571cfc 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -88,6 +88,10 @@
/* The period to insert between posting changes for coalescing */
#define POST_CHANGE_TIMER_INTERVAL_USEC (250*USEC_PER_MSEC)
+/* Pick a good default that is likely to fit into AF_UNIX and AF_INET SOCK_DGRAM datagrams, and even leaves some room
+ * for a bit of additional metadata. */
+#define DEFAULT_LINE_MAX (48*1024)
+
static int determine_path_usage(Server *s, const char *path, uint64_t *ret_used, uint64_t *ret_free) {
_cleanup_closedir_ DIR *d = NULL;
struct dirent *de;
@@ -1689,6 +1693,8 @@ int server_init(Server *s) {
s->max_level_console = LOG_INFO;
s->max_level_wall = LOG_EMERG;
+ s->line_max = DEFAULT_LINE_MAX;
+
journal_reset_metrics(&s->system_storage.metrics);
journal_reset_metrics(&s->runtime_storage.metrics);
@@ -1963,3 +1969,55 @@ static const char* const split_mode_table[_SPLIT_MAX] = {
DEFINE_STRING_TABLE_LOOKUP(split_mode, SplitMode);
DEFINE_CONFIG_PARSE_ENUM(config_parse_split_mode, split_mode, SplitMode, "Failed to parse split mode setting");
+
+int config_parse_line_max(
+ const char* unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ size_t *sz = data;
+ int r;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+ assert(data);
+
+ if (isempty(rvalue))
+ /* Empty assignment means default */
+ *sz = DEFAULT_LINE_MAX;
+ else {
+ uint64_t v;
+
+ r = parse_size(rvalue, 1024, &v);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse LineMax= value, ignoring: %s", rvalue);
+ return 0;
+ }
+
+ if (v < 79) {
+ /* Why specify 79 here as minimum line length? Simply, because the most common traditional
+ * terminal size is 80ch, and it might make sense to break one character before the natural
+ * line break would occur on that. */
+ log_syntax(unit, LOG_WARNING, filename, line, 0, "LineMax= too small, clamping to 79: %s", rvalue);
+ *sz = 79;
+ } else if (v > (uint64_t) (SSIZE_MAX-1)) {
+ /* So, why specify SSIZE_MAX-1 here? Because that's one below the largest size value read()
+ * can return, and we need one extra byte for the trailing NUL byte. Of course IRL such large
+ * memory allocations will fail anyway, hence this limit is mostly theoretical anyway, as we'll
+ * fail much earlier anyway. */
+ log_syntax(unit, LOG_WARNING, filename, line, 0, "LineMax= too large, clamping to %" PRIu64 ": %s", (uint64_t) (SSIZE_MAX-1), rvalue);
+ *sz = SSIZE_MAX-1;
+ } else
+ *sz = (size_t) v;
+ }
+
+ return 0;
+}
diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
index 6a4549b1ba..f4bdd588cb 100644
--- a/src/journal/journald-server.h
+++ b/src/journal/journald-server.h
@@ -169,6 +169,8 @@ struct Server {
usec_t last_realtime_clock;
+ size_t line_max;
+
/* Caching of client metadata */
Hashmap *client_contexts;
Prioq *client_contexts_lru;
@@ -192,6 +194,7 @@ void server_driver_message(Server *s, const char *message_id, const char *format
const struct ConfigPerfItem* journald_gperf_lookup(const char *key, GPERF_LEN_TYPE length);
int config_parse_storage(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_line_max(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
const char *storage_to_string(Storage s) _const_;
Storage storage_from_string(const char *s) _pure_;
diff --git a/src/journal/journald-stream.c b/src/journal/journald-stream.c
index f074f0476f..a44c540f67 100644
--- a/src/journal/journald-stream.c
+++ b/src/journal/journald-stream.c
@@ -63,6 +63,16 @@ typedef enum StdoutStreamState {
STDOUT_STREAM_RUNNING
} StdoutStreamState;
+/* The different types of log record terminators: a real \n was read, a NUL character was read, the maximum line length
+ * was reached, or the end of the stream was reached */
+
+typedef enum LineBreak {
+ LINE_BREAK_NEWLINE,
+ LINE_BREAK_NUL,
+ LINE_BREAK_LINE_MAX,
+ LINE_BREAK_EOF,
+} LineBreak;
+
struct StdoutStream {
Server *server;
StdoutStreamState state;
@@ -82,8 +92,9 @@ struct StdoutStream {
bool fdstore:1;
bool in_notify_queue:1;
- char buffer[LINE_MAX+1];
+ char *buffer;
size_t length;
+ size_t allocated;
sd_event_source *event_source;
@@ -93,6 +104,8 @@ struct StdoutStream {
LIST_FIELDS(StdoutStream, stdout_stream);
LIST_FIELDS(StdoutStream, stdout_stream_notify_queue);
+
+ char id_field[sizeof("_STREAM_ID=")-1 + SD_ID128_STRING_MAX];
};
void stdout_stream_free(StdoutStream *s) {
@@ -122,6 +135,7 @@ void stdout_stream_free(StdoutStream *s) {
free(s->identifier);
free(s->unit_id);
free(s->state_file);
+ free(s->buffer);
free(s);
}
@@ -172,12 +186,14 @@ static int stdout_stream_save(StdoutStream *s) {
"LEVEL_PREFIX=%i\n"
"FORWARD_TO_SYSLOG=%i\n"
"FORWARD_TO_KMSG=%i\n"
- "FORWARD_TO_CONSOLE=%i\n",
+ "FORWARD_TO_CONSOLE=%i\n"
+ "STREAM_ID=%s\n",
s->priority,
s->level_prefix,
s->forward_to_syslog,
s->forward_to_kmsg,
- s->forward_to_console);
+ s->forward_to_console,
+ s->id_field + strlen("_STREAM_ID="));
if (!isempty(s->identifier)) {
_cleanup_free_ char *escaped;
@@ -234,8 +250,8 @@ fail:
return log_error_errno(r, "Failed to save stream data %s: %m", s->state_file);
}
-static int stdout_stream_log(StdoutStream *s, const char *p) {
- struct iovec iovec[N_IOVEC_META_FIELDS + 5];
+static int stdout_stream_log(StdoutStream *s, const char *p, LineBreak line_break) {
+ struct iovec iovec[N_IOVEC_META_FIELDS + 7];
int priority;
char syslog_priority[] = "PRIORITY=\0";
char syslog_facility[sizeof("SYSLOG_FACILITY=")-1 + DECIMAL_STR_MAX(int) + 1];
@@ -268,6 +284,8 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=stdout");
+ IOVEC_SET_STRING(iovec[n++], s->id_field);
+
syslog_priority[strlen("PRIORITY=")] = '0' + LOG_PRI(priority);
IOVEC_SET_STRING(iovec[n++], syslog_priority);
@@ -282,6 +300,18 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
IOVEC_SET_STRING(iovec[n++], syslog_identifier);
}
+ if (line_break != LINE_BREAK_NEWLINE) {
+ const char *c;
+
+ /* If this log message was generated due to an uncommon line break then mention this in the log
+ * entry */
+
+ c = line_break == LINE_BREAK_NUL ? "_LINE_BREAK=nul" :
+ line_break == LINE_BREAK_LINE_MAX ? "_LINE_BREAK=line-max" :
+ "_LINE_BREAK=eof";
+ IOVEC_SET_STRING(iovec[n++], c);
+ }
+
message = strappend("MESSAGE=", p);
if (message)
IOVEC_SET_STRING(iovec[n++], message);
@@ -298,7 +328,7 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
return 0;
}
-static int stdout_stream_line(StdoutStream *s, char *p) {
+static int stdout_stream_line(StdoutStream *s, char *p, LineBreak line_break) {
int r;
char *orig;
@@ -308,6 +338,12 @@ static int stdout_stream_line(StdoutStream *s, char *p) {
orig = p;
p = strstrip(p);
+ /* line breaks by NUL, line max length or EOF are not permissible during the negotiation part of the protocol */
+ if (line_break != LINE_BREAK_NEWLINE && s->state != STDOUT_STREAM_RUNNING) {
+ log_warning("Control protocol line not properly terminated.");
+ return -EINVAL;
+ }
+
switch (s->state) {
case STDOUT_STREAM_IDENTIFIER:
@@ -390,7 +426,7 @@ static int stdout_stream_line(StdoutStream *s, char *p) {
return 0;
case STDOUT_STREAM_RUNNING:
- return stdout_stream_log(s, orig);
+ return stdout_stream_log(s, orig, line_break);
}
assert_not_reached("Unknown stream state");
@@ -409,21 +445,31 @@ static int stdout_stream_scan(StdoutStream *s, bool force_flush) {
/* XXX: This function does nothing if (s->length == 0) */
for (;;) {
- char *end;
+ LineBreak line_break;
size_t skip;
+ char *end1, *end2;
- end = memchr(p, '\n', remaining);
- if (end)
- skip = end - p + 1;
- else if (remaining >= sizeof(s->buffer) - 1) {
- end = p + sizeof(s->buffer) - 1;
+ end1 = memchr(p, '\n', remaining);
+ end2 = memchr(p, 0, end1 ? (size_t) (end1 - p) : remaining);
+
+ if (end2) {
+ /* We found a NUL terminator */
+ skip = end2 - p + 1;
+ line_break = LINE_BREAK_NUL;
+ } else if (end1) {
+ /* We found a \n terminator */
+ *end1 = 0;
+ skip = end1 - p + 1;
+ line_break = LINE_BREAK_NEWLINE;
+ } else if (remaining >= s->server->line_max) {
+ /* Force a line break after the maximum line length */
+ *(p + s->server->line_max) = 0;
skip = remaining;
+ line_break = LINE_BREAK_LINE_MAX;
} else
break;
- *end = 0;
-
- r = stdout_stream_line(s, p);
+ r = stdout_stream_line(s, p, line_break);
if (r < 0)
return r;
@@ -433,7 +479,7 @@ static int stdout_stream_scan(StdoutStream *s, bool force_flush) {
if (force_flush && remaining > 0) {
p[remaining] = 0;
- r = stdout_stream_line(s, p);
+ r = stdout_stream_line(s, p, LINE_BREAK_EOF);
if (r < 0)
return r;
@@ -451,6 +497,7 @@ static int stdout_stream_scan(StdoutStream *s, bool force_flush) {
static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
StdoutStream *s = userdata;
+ size_t limit;
ssize_t l;
int r;
@@ -461,9 +508,20 @@ static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents,
goto terminate;
}
- l = read(s->fd, s->buffer+s->length, sizeof(s->buffer)-1-s->length);
- if (l < 0) {
+ /* If the buffer is full already (discounting the extra NUL we need), add room for another 1K */
+ if (s->length + 1 >= s->allocated) {
+ if (!GREEDY_REALLOC(s->buffer, s->allocated, s->length + 1 + 1024)) {
+ log_oom();
+ goto terminate;
+ }
+ }
+ /* Try to make use of the allocated buffer in full, but never read more than the configured line size. Also,
+ * always leave room for a terminating NUL we might need to add. */
+ limit = MIN(s->allocated - 1, s->server->line_max);
+
+ l = read(s->fd, s->buffer + s->length, limit - s->length);
+ if (l < 0) {
if (errno == EAGAIN)
return 0;
@@ -490,11 +548,16 @@ terminate:
static int stdout_stream_install(Server *s, int fd, StdoutStream **ret) {
_cleanup_(stdout_stream_freep) StdoutStream *stream = NULL;
+ sd_id128_t id;
int r;
assert(s);
assert(fd >= 0);
+ r = sd_id128_randomize(&id);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate stream ID: %m");
+
stream = new0(StdoutStream, 1);
if (!stream)
return log_oom();
@@ -502,6 +565,8 @@ static int stdout_stream_install(Server *s, int fd, StdoutStream **ret) {
stream->fd = -1;
stream->priority = LOG_INFO;
+ xsprintf(stream->id_field, "_STREAM_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(id));
+
r = getpeercred(fd, &stream->ucred);
if (r < 0)
return log_error_errno(r, "Failed to determine peer credentials: %m");
@@ -575,7 +640,8 @@ static int stdout_stream_load(StdoutStream *stream, const char *fname) {
*level_prefix = NULL,
*forward_to_syslog = NULL,
*forward_to_kmsg = NULL,
- *forward_to_console = NULL;
+ *forward_to_console = NULL,
+ *stream_id = NULL;
int r;
assert(stream);
@@ -595,6 +661,7 @@ static int stdout_stream_load(StdoutStream *stream, const char *fname) {
"FORWARD_TO_CONSOLE", &forward_to_console,
"IDENTIFIER", &stream->identifier,
"UNIT", &stream->unit_id,
+ "STREAM_ID", &stream_id,
NULL);
if (r < 0)
return log_error_errno(r, "Failed to read: %s", stream->state_file);
@@ -631,6 +698,14 @@ static int stdout_stream_load(StdoutStream *stream, const char *fname) {
stream->forward_to_console = r;
}
+ if (stream_id) {
+ sd_id128_t id;
+
+ r = sd_id128_from_string(stream_id, &id);
+ if (r >= 0)
+ xsprintf(stream->id_field, "_STREAM_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(id));
+ }
+
return 0;
}
diff --git a/src/journal/journald.conf b/src/journal/journald.conf
index 2541b949be..03fce40e90 100644
--- a/src/journal/journald.conf
+++ b/src/journal/journald.conf
@@ -39,3 +39,4 @@
#MaxLevelKMsg=notice
#MaxLevelConsole=info
#MaxLevelWall=emerg
+#LineMax=48K