journal-remote-parse.c revision cb41ff2922b8a555c01d52e1038ac26360253c15
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Zbigniew Jędrzejewski-Szmek
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 "journal-remote-parse.h"
#include "journald-native.h"
#define LINE_CHUNK 8*1024u
void source_free(RemoteSource *source) {
if (!source)
return;
if (source->fd >= 0 && !source->passive_fd) {
log_debug("Closing fd:%d (%s)", source->fd, source->name);
safe_close(source->fd);
}
free(source->name);
free(source->buf);
iovw_free_contents(&source->iovw);
log_debug("Writer ref count %u", source->writer->n_ref);
writer_unref(source->writer);
sd_event_source_unref(source->event);
free(source);
}
/**
* Initialize zero-filled source with given values. On success, takes
* ownerhship of fd and writer, otherwise does not touch them.
*/
RemoteSource* source_new(int fd, bool passive_fd, char *name, Writer *writer) {
RemoteSource *source;
log_debug("Creating source for %sfd:%d (%s)",
passive_fd ? "passive " : "", fd, name);
assert(fd >= 0);
source = new0(RemoteSource, 1);
if (!source)
return NULL;
source->fd = fd;
source->passive_fd = passive_fd;
source->name = name;
source->writer = writer;
return source;
}
static char* realloc_buffer(RemoteSource *source, size_t size) {
char *b, *old = source->buf;
b = GREEDY_REALLOC(source->buf, source->size, size);
if (!b)
return NULL;
iovw_rebase(&source->iovw, old, source->buf);
return b;
}
static int get_line(RemoteSource *source, char **line, size_t *size) {
ssize_t n;
char *c = NULL;
assert(source);
assert(source->state == STATE_LINE);
assert(source->offset <= source->filled);
assert(source->filled <= source->size);
assert(source->buf == NULL || source->size > 0);
assert(source->fd >= 0);
while (true) {
if (source->buf) {
size_t start = MAX(source->scanned, source->offset);
c = memchr(source->buf + start, '\n',
source->filled - start);
if (c != NULL)
break;
}
source->scanned = source->filled;
if (source->scanned >= DATA_SIZE_MAX) {
log_error("Entry is bigger than %u bytes.", DATA_SIZE_MAX);
return -E2BIG;
}
if (source->passive_fd)
/* we have to wait for some data to come to us */
return -EWOULDBLOCK;
if (source->size - source->filled < LINE_CHUNK &&
!realloc_buffer(source,
MIN(source->filled + LINE_CHUNK, ENTRY_SIZE_MAX)))
return log_oom();
assert(source->size - source->filled >= LINE_CHUNK ||
source->size == ENTRY_SIZE_MAX);
n = read(source->fd, source->buf + source->filled,
source->size - source->filled);
if (n < 0) {
if (errno != EAGAIN && errno != EWOULDBLOCK)
log_error("read(%d, ..., %zd): %m", source->fd,
source->size - source->filled);
return -errno;
} else if (n == 0)
return 0;
source->filled += n;
}
*line = source->buf + source->offset;
*size = c + 1 - source->buf - source->offset;
source->offset += *size;
return 1;
}
int push_data(RemoteSource *source, const char *data, size_t size) {
assert(source);
assert(source->state != STATE_EOF);
if (!realloc_buffer(source, source->filled + size)) {
log_error("Failed to store received data of size %zu "
"(in addition to existing %zu bytes with %zu filled): %s",
size, source->size, source->filled, strerror(ENOMEM));
return -ENOMEM;
}
memcpy(source->buf + source->filled, data, size);
source->filled += size;
return 0;
}
static int fill_fixed_size(RemoteSource *source, void **data, size_t size) {
assert(source);
assert(source->state == STATE_DATA_START ||
source->state == STATE_DATA ||
source->state == STATE_DATA_FINISH);
assert(size <= DATA_SIZE_MAX);
assert(source->offset <= source->filled);
assert(source->filled <= source->size);
assert(source->buf != NULL || source->size == 0);
assert(source->buf == NULL || source->size > 0);
assert(source->fd >= 0);
assert(data);
while (source->filled - source->offset < size) {
int n;
if (source->passive_fd)
/* we have to wait for some data to come to us */
return -EWOULDBLOCK;
if (!realloc_buffer(source, source->offset + size))
return log_oom();
n = read(source->fd, source->buf + source->filled,
source->size - source->filled);
if (n < 0) {
if (errno != EAGAIN && errno != EWOULDBLOCK)
log_error("read(%d, ..., %zd): %m", source->fd,
source->size - source->filled);
return -errno;
} else if (n == 0)
return 0;
source->filled += n;
}
*data = source->buf + source->offset;
source->offset += size;
return 1;
}
static int get_data_size(RemoteSource *source) {
int r;
void *data;
assert(source);
assert(source->state == STATE_DATA_START);
assert(source->data_size == 0);
r = fill_fixed_size(source, &data, sizeof(uint64_t));
if (r <= 0)
return r;
source->data_size = le64toh( *(uint64_t *) data );
if (source->data_size > DATA_SIZE_MAX) {
log_error("Stream declares field with size %zu > DATA_SIZE_MAX = %u",
source->data_size, DATA_SIZE_MAX);
return -EINVAL;
}
if (source->data_size == 0)
log_warning("Binary field with zero length");
return 1;
}
static int get_data_data(RemoteSource *source, void **data) {
int r;
assert(source);
assert(data);
assert(source->state == STATE_DATA);
r = fill_fixed_size(source, data, source->data_size);
if (r <= 0)
return r;
return 1;
}
static int get_data_newline(RemoteSource *source) {
int r;
char *data;
assert(source);
assert(source->state == STATE_DATA_FINISH);
r = fill_fixed_size(source, (void**) &data, 1);
if (r <= 0)
return r;
assert(data);
if (*data != '\n') {
log_error("expected newline, got '%c'", *data);
return -EINVAL;
}
return 1;
}
static int process_dunder(RemoteSource *source, char *line, size_t n) {
const char *timestamp;
int r;
assert(line);
assert(n > 0);
assert(line[n-1] == '\n');
/* XXX: is it worth to support timestamps in extended format?
* We don't produce them, but who knows... */
timestamp = startswith(line, "__CURSOR=");
if (timestamp)
/* ignore __CURSOR */
return 1;
timestamp = startswith(line, "__REALTIME_TIMESTAMP=");
if (timestamp) {
long long unsigned x;
line[n-1] = '\0';
r = safe_atollu(timestamp, &x);
if (r < 0)
log_warning("Failed to parse __REALTIME_TIMESTAMP: '%s'", timestamp);
else
source->ts.realtime = x;
return r < 0 ? r : 1;
}
timestamp = startswith(line, "__MONOTONIC_TIMESTAMP=");
if (timestamp) {
long long unsigned x;
line[n-1] = '\0';
r = safe_atollu(timestamp, &x);
if (r < 0)
log_warning("Failed to parse __MONOTONIC_TIMESTAMP: '%s'", timestamp);
else
source->ts.monotonic = x;
return r < 0 ? r : 1;
}
timestamp = startswith(line, "__");
if (timestamp) {
log_notice("Unknown dunder line %s", line);
return 1;
}
/* no dunder */
return 0;
}
int process_data(RemoteSource *source) {
int r;
switch(source->state) {
case STATE_LINE: {
char *line, *sep;
size_t n;
assert(source->data_size == 0);
r = get_line(source, &line, &n);
if (r < 0)
return r;
if (r == 0) {
source->state = STATE_EOF;
return r;
}
assert(n > 0);
assert(line[n-1] == '\n');
if (n == 1) {
log_trace("Received empty line, event is ready");
return 1;
}
r = process_dunder(source, line, n);
if (r != 0)
return r < 0 ? r : 0;
/* MESSAGE=xxx\n
or
COREDUMP\n
LLLLLLLL0011223344...\n
*/
sep = memchr(line, '=', n);
if (sep)
/* chomp newline */
n--;
else
/* replace \n with = */
line[n-1] = '=';
log_trace("Received: %.*s", (int) n, line);
r = iovw_put(&source->iovw, line, n);
if (r < 0) {
log_error("Failed to put line in iovect");
return r;
}
if (!sep)
source->state = STATE_DATA_START;
return 0; /* continue */
}
case STATE_DATA_START:
assert(source->data_size == 0);
r = get_data_size(source);
// log_debug("get_data_size() -> %d", r);
if (r < 0)
return r;
if (r == 0) {
source->state = STATE_EOF;
return 0;
}
source->state = source->data_size > 0 ?
STATE_DATA : STATE_DATA_FINISH;
return 0; /* continue */
case STATE_DATA: {
void *data;
assert(source->data_size > 0);
r = get_data_data(source, &data);
// log_debug("get_data_data() -> %d", r);
if (r < 0)
return r;
if (r == 0) {
source->state = STATE_EOF;
return 0;
}
assert(data);
r = iovw_put(&source->iovw, data, source->data_size);
if (r < 0) {
log_error("failed to put binary buffer in iovect");
return r;
}
source->state = STATE_DATA_FINISH;
return 0; /* continue */
}
case STATE_DATA_FINISH:
r = get_data_newline(source);
// log_debug("get_data_newline() -> %d", r);
if (r < 0)
return r;
if (r == 0) {
source->state = STATE_EOF;
return 0;
}
source->data_size = 0;
source->state = STATE_LINE;
return 0; /* continue */
default:
assert_not_reached("wtf?");
}
}
int process_source(RemoteSource *source, bool compress, bool seal) {
size_t remain, target;
int r;
assert(source);
assert(source->writer);
r = process_data(source);
if (r <= 0)
return r;
/* We have a full event */
log_trace("Received a full event from source@%p fd:%d (%s)",
source, source->fd, source->name);
if (!source->iovw.count) {
log_warning("Entry with no payload, skipping");
goto freeing;
}
assert(source->iovw.iovec);
assert(source->iovw.count);
r = writer_write(source->writer, &source->iovw, &source->ts, compress, seal);
if (r < 0)
log_error("Failed to write entry of %zu bytes: %s",
iovw_size(&source->iovw), strerror(-r));
else
r = 1;
freeing:
iovw_free_contents(&source->iovw);
/* possibly reset buffer position */
remain = source->filled - source->offset;
if (remain == 0) /* no brainer */
source->offset = source->scanned = source->filled = 0;
else if (source->offset > source->size - source->filled &&
source->offset > remain) {
memcpy(source->buf, source->buf + source->offset, remain);
source->offset = source->scanned = 0;
source->filled = remain;
}
target = source->size;
while (target > 16 * LINE_CHUNK && remain < target / 2)
target /= 2;
if (target < source->size) {
char *tmp;
tmp = realloc(source->buf, target);
if (!tmp)
log_warning("Failed to reallocate buffer to (smaller) size %zu",
target);
else {
log_debug("Reallocated buffer from %zu to %zu bytes",
source->size, target);
source->buf = tmp;
source->size = target;
}
}
return r;
}