Systemd/src/journal/journald-server.h
Lennart Poettering ec20fe5ffb journald: make maximum size of stream log lines configurable and bump it to 48K (#6838)
This adds a new setting LineMax= to journald.conf, and sets it by
default to 48K. When we convert stream-based stdout/stderr logging into
record-based log entries, read up to the specified amount of bytes
before forcing a line-break.

This also makes three related changes:

- When a NUL byte is read we'll not recognize this as alternative line
  break, instead of silently dropping everything after it. (see #4863)

- The reason for a line-break is now encoded in the log record, if it
  wasn't a plain newline. Specifically, we distuingish "nul",
  "line-max" and "eof", for line breaks due to NUL byte, due to the
  maximum line length as configured with LineMax= or due to end of
  stream. This data is stored in the new implicit _LINE_BREAK= field.
  It's not synthesized for plain \n line breaks.

- A randomized 128bit ID is assigned to each log stream.

With these three changes in place it's (mostly) possible to reconstruct
the original byte streams from log data, as (most) of the context of
the conversion from the byte stream to log records is saved now. (So,
the only bits we still drop are empty lines. Which might be something to
look into in a future change, and which is outside of the scope of this
work)

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=86465
See: #4863
Replaces: #4875
2017-09-22 10:22:24 +02:00

217 lines
6.5 KiB
C

#pragma once
/***
This file is part of systemd.
Copyright 2011 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 <sys/types.h>
#include "sd-event.h"
typedef struct Server Server;
#include "hashmap.h"
#include "journal-file.h"
#include "journald-context.h"
#include "journald-rate-limit.h"
#include "journald-stream.h"
#include "list.h"
#include "prioq.h"
typedef enum Storage {
STORAGE_AUTO,
STORAGE_VOLATILE,
STORAGE_PERSISTENT,
STORAGE_NONE,
_STORAGE_MAX,
_STORAGE_INVALID = -1
} Storage;
typedef enum SplitMode {
SPLIT_UID,
SPLIT_LOGIN, /* deprecated */
SPLIT_NONE,
_SPLIT_MAX,
_SPLIT_INVALID = -1
} SplitMode;
typedef struct JournalStorageSpace {
usec_t timestamp;
uint64_t available;
uint64_t limit;
uint64_t vfs_used; /* space used by journal files */
uint64_t vfs_available;
} JournalStorageSpace;
typedef struct JournalStorage {
const char *name;
char *path;
JournalMetrics metrics;
JournalStorageSpace space;
} JournalStorage;
struct Server {
int syslog_fd;
int native_fd;
int stdout_fd;
int dev_kmsg_fd;
int audit_fd;
int hostname_fd;
int notify_fd;
sd_event *event;
sd_event_source *syslog_event_source;
sd_event_source *native_event_source;
sd_event_source *stdout_event_source;
sd_event_source *dev_kmsg_event_source;
sd_event_source *audit_event_source;
sd_event_source *sync_event_source;
sd_event_source *sigusr1_event_source;
sd_event_source *sigusr2_event_source;
sd_event_source *sigterm_event_source;
sd_event_source *sigint_event_source;
sd_event_source *sigrtmin1_event_source;
sd_event_source *hostname_event_source;
sd_event_source *notify_event_source;
sd_event_source *watchdog_event_source;
JournalFile *runtime_journal;
JournalFile *system_journal;
OrderedHashmap *user_journals;
uint64_t seqnum;
char *buffer;
size_t buffer_size;
JournalRateLimit *rate_limit;
usec_t sync_interval_usec;
usec_t rate_limit_interval;
unsigned rate_limit_burst;
JournalStorage runtime_storage;
JournalStorage system_storage;
bool compress;
bool seal;
bool read_kmsg;
bool forward_to_kmsg;
bool forward_to_syslog;
bool forward_to_console;
bool forward_to_wall;
unsigned n_forward_syslog_missed;
usec_t last_warn_forward_syslog_missed;
uint64_t var_available_timestamp;
usec_t max_retention_usec;
usec_t max_file_usec;
usec_t oldest_file_usec;
LIST_HEAD(StdoutStream, stdout_streams);
LIST_HEAD(StdoutStream, stdout_streams_notify_queue);
unsigned n_stdout_streams;
char *tty_path;
int max_level_store;
int max_level_syslog;
int max_level_kmsg;
int max_level_console;
int max_level_wall;
Storage storage;
SplitMode split_mode;
MMapCache *mmap;
Set *deferred_closes;
struct udev *udev;
uint64_t *kernel_seqnum;
bool dev_kmsg_readable:1;
bool send_watchdog:1;
bool sent_notify_ready:1;
bool sync_scheduled:1;
char machine_id_field[sizeof("_MACHINE_ID=") + 32];
char boot_id_field[sizeof("_BOOT_ID=") + 32];
char *hostname_field;
/* Cached cgroup root, so that we don't have to query that all the time */
char *cgroup_root;
usec_t watchdog_usec;
usec_t last_realtime_clock;
size_t line_max;
/* Caching of client metadata */
Hashmap *client_contexts;
Prioq *client_contexts_lru;
ClientContext *my_context; /* the context of journald itself */
ClientContext *pid1_context; /* the context of PID 1 */
};
#define SERVER_MACHINE_ID(s) ((s)->machine_id_field + strlen("_MACHINE_ID="))
#define N_IOVEC_META_FIELDS 22
#define N_IOVEC_KERNEL_FIELDS 64
#define N_IOVEC_UDEV_FIELDS 32
#define N_IOVEC_OBJECT_FIELDS 14
#define N_IOVEC_PAYLOAD_FIELDS 15
void server_dispatch_message(Server *s, struct iovec *iovec, unsigned n, unsigned m, ClientContext *c, const struct timeval *tv, int priority, pid_t object_pid);
void server_driver_message(Server *s, const char *message_id, const char *format, ...) _printf_(3,0) _sentinel_;
/* gperf lookup function */
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_;
int config_parse_split_mode(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 *split_mode_to_string(SplitMode s) _const_;
SplitMode split_mode_from_string(const char *s) _pure_;
int server_init(Server *s);
void server_done(Server *s);
void server_sync(Server *s);
int server_vacuum(Server *s, bool verbose);
void server_rotate(Server *s);
int server_schedule_sync(Server *s, int priority);
int server_flush_to_var(Server *s, bool require_flag_file);
void server_maybe_append_tags(Server *s);
int server_process_datagram(sd_event_source *es, int fd, uint32_t revents, void *userdata);
void server_space_usage_message(Server *s, JournalStorage *storage);