fpm_stdio.c

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    /* (c) 2007,2008 Andrei Nigmatulin */
 
#include "fpm_config.h"
 
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
 
#include "php_syslog.h"
#include "php_network.h"
 
#include "fpm.h"
#include "fpm_children.h"
#include "fpm_cleanup.h"
#include "fpm_events.h"
#include "fpm_sockets.h"
#include "fpm_stdio.h"
#include "zlog.h"
 
static int fd_stderr_original = -1;
static int fd_stdout[2];
static int fd_stderr[2];
 
int fpm_stdio_init_main(void)
{
    int fd = open("/dev/null", O_RDWR);
 
    if (0 > fd) {
        zlog(ZLOG_SYSERROR, "failed to init stdio: open(\"/dev/null\")");
        return -1;
    }
 
    if (0 > dup2(fd, STDIN_FILENO) || 0 > dup2(fd, STDOUT_FILENO)) {
        zlog(ZLOG_SYSERROR, "failed to init stdio: dup2()");
        close(fd);
        return -1;
    }
    close(fd);
    return 0;
}
 
static inline int fpm_use_error_log(void) {
    /*
     * the error_log is NOT used when running in foreground
     * and from a tty (user looking at output).
     * So, error_log is used by
     * - SysV init launch php-fpm as a daemon
     * - Systemd launch php-fpm in foreground
     */
#ifdef HAVE_UNISTD_H
    if (fpm_global_config.daemonize || (!isatty(STDERR_FILENO) && !fpm_globals.force_stderr)) {
#else
    if (fpm_global_config.daemonize) {
#endif
        return 1;
    }
    return 0;
}
 
int fpm_stdio_init_final(void)
{
    if (0 > fpm_stdio_redirect_stderr_to_error_log() ||
        0 > fpm_stdio_redirect_stderr_to_dev_null_for_syslog()) {
 
        return -1;
    }
 
    zlog_set_launched();
    return 0;
}
/* }}} */
 
int fpm_stdio_save_original_stderr(void)
{
    /* STDERR fd gets lost after calling fpm_stdio_init_final() (check GH-8555) so it can be saved.
     * It should be used only when PHP-FPM is not daemonized otherwise it might break some
     * applications (e.g. GH-9754). */
    zlog(ZLOG_DEBUG, "saving original STDERR fd: dup()");
    fd_stderr_original = dup(STDERR_FILENO);
    if (0 > fd_stderr_original) {
        zlog(ZLOG_SYSERROR, "failed to save original STDERR fd, access.log records may appear in error_log: dup()");
        return -1;
    }
 
    return 0;
}
 
int fpm_stdio_restore_original_stderr(int close_after_restore)
{
    /* Restore original STDERR fd if it was previously saved. */
    if (-1 != fd_stderr_original) {
        zlog(ZLOG_DEBUG, "restoring original STDERR fd: dup2()");
        if (0 > dup2(fd_stderr_original, STDERR_FILENO)) {
            zlog(ZLOG_SYSERROR, "failed to restore original STDERR fd, access.log records may appear in error_log: dup2()");
            return -1;
        } else {
            if (close_after_restore) {
                close(fd_stderr_original);
            }
        }
    }
 
    return 0;
}
 
int fpm_stdio_redirect_stderr_to_error_log(void)
{
    if (fpm_use_error_log()) {
        /* prevent duping if logging to syslog */
        if (fpm_globals.error_log_fd > 0 && fpm_globals.error_log_fd != STDERR_FILENO) {
 
            /* there might be messages to stderr from other parts of the code, we need to log them all */
            if (0 > dup2(fpm_globals.error_log_fd, STDERR_FILENO)) {
                zlog(ZLOG_SYSERROR, "failed to tie stderr fd with error_log fd: dup2()");
                return -1;
            }
        }
    }
 
    return 0;
}
 
int fpm_stdio_redirect_stderr_to_dev_null_for_syslog(void)
{
    if (fpm_use_error_log()) {
#ifdef HAVE_SYSLOG_H
        if (fpm_globals.error_log_fd == ZLOG_SYSLOG) {
            /* dup to /dev/null when using syslog */
            dup2(STDOUT_FILENO, STDERR_FILENO);
        }
#endif
    }
 
    return 0;
}
 
int fpm_stdio_init_child(struct fpm_worker_pool_s *wp) /* {{{ */
{
#ifdef HAVE_SYSLOG_H
    if (fpm_globals.error_log_fd == ZLOG_SYSLOG) {
        php_closelog(); /* ensure to close syslog not to interrupt with PHP syslog code */
    } else
#endif
 
    /* Notice: child cannot use master error_log
     * because not aware when being reopen
     * else, should use if (!fpm_use_error_log())
     */
    if (fpm_globals.error_log_fd > 0) {
        close(fpm_globals.error_log_fd);
    }
    fpm_globals.error_log_fd = -1;
    zlog_set_fd(-1, 0);
 
    return 0;
}
/* }}} */
 
#define FPM_STDIO_CMD_FLUSH "\0fscf"
 
int fpm_stdio_flush_child(void)
{
    return write(STDERR_FILENO, FPM_STDIO_CMD_FLUSH, sizeof(FPM_STDIO_CMD_FLUSH));
}
 
static void fpm_stdio_child_said(struct fpm_event_s *ev, short which, void *arg) /* {{{ */
{
    int fd = ev->fd;
    char buf[1024];
    struct fpm_child_s *child;
    int is_stdout;
    struct fpm_event_s *event;
    int in_buf = 0, cmd_pos = 0, pos, start;
    int read_fail = 0, create_log_stream;
    struct zlog_stream *log_stream;
 
    if (!arg) {
        return;
    }
    child = (struct fpm_child_s *) arg;
 
    is_stdout = (fd == child->fd_stdout);
    if (is_stdout) {
        event = &child->ev_stdout;
    } else {
        event = &child->ev_stderr;
    }
 
    create_log_stream = !child->log_stream;
    if (create_log_stream) {
        log_stream = child->log_stream = malloc(sizeof(struct zlog_stream));
        zlog_stream_init_ex(log_stream, ZLOG_WARNING, STDERR_FILENO);
        zlog_stream_set_decorating(log_stream, child->wp->config->decorate_workers_output);
        zlog_stream_set_wrapping(log_stream, ZLOG_TRUE);
        zlog_stream_set_msg_prefix(log_stream, STREAM_SET_MSG_PREFIX_FMT,
                child->wp->config->name, (int) child->pid, is_stdout ? "stdout" : "stderr");
        zlog_stream_set_msg_quoting(log_stream, ZLOG_TRUE);
        zlog_stream_set_is_stdout(log_stream, is_stdout);
        zlog_stream_set_child_pid(log_stream, (int)child->pid);
    } else {
        log_stream = child->log_stream;
        // if fd type (stdout/stderr) or child's pid is changed,
        // then the stream will be finished and msg's prefix will be reinitialized
        if (log_stream->is_stdout != (unsigned int)is_stdout || log_stream->child_pid != (int)child->pid) {
            zlog_stream_finish(log_stream);
            zlog_stream_set_msg_prefix(log_stream, STREAM_SET_MSG_PREFIX_FMT,
                    child->wp->config->name, (int) child->pid, is_stdout ? "stdout" : "stderr");
            zlog_stream_set_is_stdout(log_stream, is_stdout);
            zlog_stream_set_child_pid(log_stream, (int)child->pid);
        }
    }
 
    while (1) {
stdio_read:
        in_buf = read(fd, buf, sizeof(buf) - 1);
        if (in_buf <= 0) { /* no data */
            if (in_buf == 0 || !PHP_IS_TRANSIENT_ERROR(errno)) {
                /* pipe is closed or error */
                read_fail = (in_buf < 0) ? in_buf : 1;
            }
            break;
        }
        start = 0;
        if (cmd_pos > 0) {
            if  ((sizeof(FPM_STDIO_CMD_FLUSH) - cmd_pos) <= in_buf &&
                    !memcmp(buf, &FPM_STDIO_CMD_FLUSH[cmd_pos], sizeof(FPM_STDIO_CMD_FLUSH) - cmd_pos)) {
                zlog_stream_finish(log_stream);
                start = sizeof(FPM_STDIO_CMD_FLUSH) - cmd_pos;
            } else {
                zlog_stream_str(log_stream, &FPM_STDIO_CMD_FLUSH[0], cmd_pos);
            }
            cmd_pos = 0;
        }
        for (pos = start; pos < in_buf; pos++) {
            switch (buf[pos]) {
                case '\n':
                    zlog_stream_str(log_stream, buf + start, pos - start);
                    zlog_stream_finish(log_stream);
                    start = pos + 1;
                    break;
                case '\0':
                    if (pos + sizeof(FPM_STDIO_CMD_FLUSH) <= in_buf) {
                        if (!memcmp(buf + pos, FPM_STDIO_CMD_FLUSH, sizeof(FPM_STDIO_CMD_FLUSH))) {
                            zlog_stream_str(log_stream, buf + start, pos - start);
                            zlog_stream_finish(log_stream);
                            start = pos + sizeof(FPM_STDIO_CMD_FLUSH);
                            pos = start - 1;
                        }
                    } else if (!memcmp(buf + pos, FPM_STDIO_CMD_FLUSH, in_buf - pos)) {
                        cmd_pos = in_buf - pos;
                        zlog_stream_str(log_stream, buf + start, pos - start);
                        goto stdio_read;
                    }
                    break;
            }
        }
        if (start < pos) {
            zlog_stream_str(log_stream, buf + start, pos - start);
        }
    }
 
    if (read_fail) {
        if (create_log_stream) {
            zlog_stream_set_msg_suffix(log_stream, NULL, ", pipe is closed");
            zlog_stream_finish(log_stream);
        }
        if (read_fail < 0) {
            zlog(ZLOG_SYSERROR, "unable to read what child %d said into %s", (int) child->pid, is_stdout ? "stdout" : "stderr");
        }
 
        fpm_event_del(event);
 
        child->postponed_free = true;
        if (is_stdout) {
            close(child->fd_stdout);
            child->fd_stdout = -1;
        } else {
            close(child->fd_stderr);
            child->fd_stderr = -1;
        }
    }
}
/* }}} */
 
int fpm_stdio_prepare_pipes(struct fpm_child_s *child) /* {{{ */
{
    if (0 == child->wp->config->catch_workers_output) { /* not required */
        return 0;
    }
 
    if (0 > pipe(fd_stdout)) {
        zlog(ZLOG_SYSERROR, "failed to prepare the stdout pipe");
        return -1;
    }
 
    if (0 > pipe(fd_stderr)) {
        zlog(ZLOG_SYSERROR, "failed to prepare the stderr pipe");
        close(fd_stdout[0]);
        close(fd_stdout[1]);
        return -1;
    }
 
    if (0 > fd_set_blocked(fd_stdout[0], 0) || 0 > fd_set_blocked(fd_stderr[0], 0)) {
        zlog(ZLOG_SYSERROR, "failed to unblock pipes");
        close(fd_stdout[0]);
        close(fd_stdout[1]);
        close(fd_stderr[0]);
        close(fd_stderr[1]);
        return -1;
    }
    return 0;
}
/* }}} */
 
int fpm_stdio_parent_use_pipes(struct fpm_child_s *child) /* {{{ */
{
    if (0 == child->wp->config->catch_workers_output) { /* not required */
        return 0;
    }
 
    close(fd_stdout[1]);
    close(fd_stderr[1]);
 
    child->fd_stdout = fd_stdout[0];
    child->fd_stderr = fd_stderr[0];
 
    fpm_event_set(&child->ev_stdout, child->fd_stdout, FPM_EV_READ, fpm_stdio_child_said, child);
    fpm_event_add(&child->ev_stdout, 0);
 
    fpm_event_set(&child->ev_stderr, child->fd_stderr, FPM_EV_READ, fpm_stdio_child_said, child);
    fpm_event_add(&child->ev_stderr, 0);
    return 0;
}
/* }}} */
 
int fpm_stdio_discard_pipes(struct fpm_child_s *child) /* {{{ */
{
    if (0 == child->wp->config->catch_workers_output) { /* not required */
        return 0;
    }
 
    close(fd_stdout[1]);
    close(fd_stderr[1]);
 
    close(fd_stdout[0]);
    close(fd_stderr[0]);
    return 0;
}
/* }}} */
 
void fpm_stdio_child_use_pipes(struct fpm_child_s *child) /* {{{ */
{
    if (child->wp->config->catch_workers_output) {
        dup2(fd_stdout[1], STDOUT_FILENO);
        dup2(fd_stderr[1], STDERR_FILENO);
        close(fd_stdout[0]); close(fd_stdout[1]);
        close(fd_stderr[0]); close(fd_stderr[1]);
    } else {
        /* stdout of parent is always /dev/null */
        dup2(STDOUT_FILENO, STDERR_FILENO);
    }
}
/* }}} */
 
int fpm_stdio_open_error_log(int reopen) /* {{{ */
{
    int fd;
 
#ifdef HAVE_SYSLOG_H
    if (!strcasecmp(fpm_global_config.error_log, "syslog")) {
        php_openlog(fpm_global_config.syslog_ident, LOG_PID | LOG_CONS, fpm_global_config.syslog_facility);
        fpm_globals.error_log_fd = ZLOG_SYSLOG;
        if (fpm_use_error_log()) {
            zlog_set_fd(fpm_globals.error_log_fd, 0);
        }
        return 0;
    }
#endif
 
    fd = open(fpm_global_config.error_log, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
 
    if (0 > fd) {
        zlog(ZLOG_SYSERROR, "failed to open error_log (%s)", fpm_global_config.error_log);
        return -1;
    }
 
    if (reopen) {
        dup2(fd, fpm_globals.error_log_fd);
        close(fd);
        fd = fpm_globals.error_log_fd; /* for FD_CLOSEXEC to work */
    } else {
        fpm_globals.error_log_fd = fd;
        if (fpm_use_error_log()) {
            bool is_stderr = (
                strcmp(fpm_global_config.error_log, "/dev/stderr") == 0 ||
                strcmp(fpm_global_config.error_log, "/proc/self/fd/2") == 0
            );
            zlog_set_fd(fpm_globals.error_log_fd, is_stderr);
        }
    }
    if (0 > fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC)) {
        zlog(ZLOG_WARNING, "failed to change attribute of error_log");
    }
    return 0;
}
/* }}} */