lighttpd1.4/src/fdlog_maint.c

338 lines
8.4 KiB
C

#include "first.h"
#include "fdlog.h"
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "fdevent.h"
#include "ck.h"
#include "log.h"
/*
* Notes:
* - Use of "/dev/stdin" and "/dev/stdout" is not recommended
* since those are manipulated at startup in server_main_setup()
* "/dev/stderr" might similarly be manipulated at startup.
* - Use of "/proc/self/fd/..." is permitted, and admin may use a shell script
* to dup standard fds to higher numbers before starting lighttpd if admin
* wants to direct logs to the standard fds on which lighttpd was started.
* Future: might detect and use the open fd rather than open() a new fd to the
* already-open path. If so, should stat() to check that fd actually exists,
* and must check for and not close() those paths when closing fdlog_st fds.
*/
struct fdlog_files_t {
fdlog_st **ptr;
uint32_t used;
uint32_t size;
};
static struct fdlog_files_t fdlog_files;
typedef struct fdlog_pipe {
/* ((fdlog_st *) is ptr rather than inlined struct since multiple callers
* might have reference to (fdlog_st *), and if fdlog_pipes.ptr is
* reallocated those ptrs could be invalided if inlined struct) */
fdlog_st *fdlog; /*(contains write-side of pipe)*/
pid_t pid;
int fd; /*(contains read-side of pipe)*/
unix_time64_t start;
} fdlog_pipe;
struct fdlog_pipes_t {
fdlog_pipe *ptr;
uint32_t used;
uint32_t size;
};
static struct fdlog_pipes_t fdlog_pipes;
static pid_t
fdlog_pipe_spawn (const char * const fn, const int rfd)
{
char *args[4];
int devnull = fdevent_open_devnull();
pid_t pid;
if (-1 == devnull) {
return -1;
}
*(const char **)&args[0] = "/bin/sh";
*(const char **)&args[1] = "-c";
*(const char **)&args[2] = fn;
args[3] = NULL;
pid = fdevent_fork_execve(args[0], args, NULL, rfd, devnull, devnull, -1);
if (pid > 0) {
close(devnull);
}
else {
int errnum = errno;
close(devnull);
errno = errnum;
}
return pid;
}
__attribute_noinline__
static int
fdlog_pipe_restart (fdlog_pipe * const fdp, const unix_time64_t ts)
{
if (fdp->start + 5 < ts) { /* limit restart to once every 5 sec */
/* restart child process using existing pipe fds */
fdp->start = ts;
fdp->pid = fdlog_pipe_spawn(fdp->fdlog->fn, fdp->fd);
}
return (fdp->pid > 0) ? 1 : -1;
}
void
fdlog_pipes_restart (const unix_time64_t ts)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_pipe * const fdp = fdlog_pipes.ptr+i;
if (fdp->pid > 0) continue;
fdlog_pipe_restart(fdp, ts);
}
}
int
fdlog_pipes_waitpid_cb (const pid_t pid)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_pipe * const fdp = fdlog_pipes.ptr+i;
if (fdp->pid != pid) continue;
fdp->pid = -1;
return fdlog_pipe_restart(fdp, log_monotonic_secs);
}
return 0;
}
static void
fdlog_pipes_close (fdlog_st * const retain)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_pipe * const fdp = fdlog_pipes.ptr+i;
fdlog_st * const fdlog = fdp->fdlog;
close(fdp->fd);
fdp->fd = -1;
if (fdlog == retain) continue; /*(free'd later)*/
fdlog_free(fdlog);
}
free(fdlog_pipes.ptr);
fdlog_pipes.ptr = NULL;
fdlog_pipes.used = 0;
fdlog_pipes.size = 0;
}
void
fdlog_pipes_abandon_pids (void)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_pipe * const fdp = fdlog_pipes.ptr+i;
fdp->pid = -1;
}
}
void
fdlog_pipe_serrh (const int fd)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_st * const fdlog = fdlog_pipes.ptr[i].fdlog;
if (fdlog->fd != fd) continue;
fdlog->fd = STDERR_FILENO;
break;
}
}
static fdlog_st *
fdlog_pipe_init (const char * const fn, const int fds[2], const pid_t pid)
{
if (fdlog_pipes.used == fdlog_pipes.size) {
fdlog_pipes.size += 4;
fdlog_pipes.ptr =
realloc(fdlog_pipes.ptr, fdlog_pipes.size * sizeof(fdlog_pipe));
force_assert(fdlog_pipes.ptr);
}
fdlog_pipe * const fdp = fdlog_pipes.ptr + fdlog_pipes.used++;
fdp->fd = fds[0];
fdp->pid = pid;
fdp->start = log_monotonic_secs;
return (fdp->fdlog = fdlog_init(fn, fds[1], FDLOG_PIPE));
}
static fdlog_st *
fdlog_pipe_open (const char * const fn)
{
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
fdlog_st * const fdlog = fdlog_pipes.ptr[i].fdlog;
if (0 != strcmp(fdlog->fn, fn)) continue;
return fdlog;
}
int fds[2];
if (fdevent_pipe_cloexec(fds, 65536))
return NULL;
pid_t pid = fdlog_pipe_spawn(fn, fds[0]);
if (pid > 0) {
/*(nonblocking write() from lighttpd)*/
if (0 != fdevent_fcntl_set_nb(fds[1])) { /*(ignore)*/ }
return fdlog_pipe_init(fn, fds, pid);
}
else {
int errnum = errno;
close(fds[0]);
close(fds[1]);
errno = errnum;
return NULL;
}
}
static fdlog_st *
fdlog_file_init (const char * const fn, const int fd)
{
if (fdlog_files.used == fdlog_files.size) {
fdlog_files.size += 4;
fdlog_files.ptr =
realloc(fdlog_files.ptr, fdlog_files.size * sizeof(fdlog_st *));
force_assert(fdlog_files.ptr);
}
return (fdlog_files.ptr[fdlog_files.used++] = fdlog_init(fn,fd,FDLOG_FILE));
}
static int
fdlog_file_open_fd (const char * const fn)
{
int flags = O_APPEND | O_WRONLY | O_CREAT;
return fdevent_open_cloexec(fn, 1, flags, 0644); /*(permit symlinks)*/
}
static fdlog_st *
fdlog_file_open (const char * const fn)
{
for (uint32_t i = 0; i < fdlog_files.used; ++i) {
fdlog_st * const fdlog = fdlog_files.ptr[i];
if (0 != strcmp(fdlog->fn, fn)) continue;
return fdlog;
}
int fd = fdlog_file_open_fd(fn);
return (-1 != fd) ? fdlog_file_init(fn, fd) : NULL;
}
fdlog_st *
fdlog_open (const char * const fn)
{
return (fn[0] != '|')
? fdlog_file_open(fn)
: fdlog_pipe_open(fn+1); /*(skip the '|')*/
}
void
fdlog_files_flush (fdlog_st * const errh, const int memrel)
{
for (uint32_t i = 0; i < fdlog_files.used; ++i) {
fdlog_st * const fdlog = fdlog_files.ptr[i];
buffer * const b = &fdlog->b;
if (!buffer_is_blank(b)) {
const ssize_t wr = write_all(fdlog->fd, BUF_PTR_LEN(b));
buffer_clear(b); /*(clear buffer, even on error)*/
if (-1 == wr)
log_perror(errh, __FILE__, __LINE__,
"error flushing log %s", fdlog->fn);
}
if (memrel && b->ptr) buffer_free_ptr(b);
}
}
void
fdlog_files_cycle (fdlog_st * const errh)
{
fdlog_files_flush(errh, 0);
for (uint32_t i = 0; i < fdlog_files.used; ++i) {
fdlog_st * const fdlog = fdlog_files.ptr[i];
int fd = fdlog_file_open_fd(fdlog->fn);
if (-1 != fd) {
if (fdlog->fd > STDERR_FILENO) {
close(fdlog->fd);
fdlog->fd = fd;
}
else {
if (fdlog->fd != dup2(fd, fdlog->fd))
log_perror(errh, __FILE__, __LINE__,
"dup2() %s to %d", fdlog->fn, fdlog->fd);
close(fd);
}
}
else {
log_perror(errh, __FILE__, __LINE__,
"error cycling log %s", fdlog->fn);
/*(leave prior log file open)*/
}
}
}
static void
fdlog_files_close (fdlog_st * const retain)
{
fdlog_files_flush(retain, 0);
for (uint32_t i = 0; i < fdlog_files.used; ++i) {
fdlog_st * const fdlog = fdlog_files.ptr[i];
if (fdlog == retain) continue; /*(free'd later)*/
fdlog_free(fdlog);
}
free(fdlog_files.ptr);
fdlog_files.ptr = NULL;
fdlog_files.used = 0;
fdlog_files.size = 0;
}
void
fdlog_closeall (fdlog_st * const errh)
{
fdlog_files_close(errh);
fdlog_pipes_close(errh);
}
void
fdlog_flushall (fdlog_st * const errh)
{
fdlog_files_flush(errh, 1); /*(flush, then release buffer memory)*/
/*(at the moment, pipe loggers clear buffer after each write attempt,
* so there is nothing to flush, though there are buffers to be freed)*/
for (uint32_t i = 0; i < fdlog_pipes.used; ++i) {
buffer * const b = &fdlog_pipes.ptr[i].fdlog->b;
if (b->ptr) buffer_free_ptr(b);
}
if (errh->b.ptr) buffer_free_ptr(&errh->b);
}