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/*
* watchfrr CLI functions.
*
* Copyright (C) 2016 David Lamparter for NetDEF, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include <sys/wait.h>
#include "memory.h"
#include "log.h"
#include "vty.h"
#include "command.h"
#include "watchfrr.h"
pid_t integrated_write_pid;
static int integrated_result_fd;
DEFUN(config_write_integrated,
config_write_integrated_cmd,
"write integrated",
"Write running configuration to memory, network, or terminal\n"
"Write integrated all-daemon frr.conf file\n")
{
pid_t child;
sigset_t oldmask, sigmask;
const char *e_inprog = "Configuration write already in progress.";
const char *e_dmn = "Not all daemons are up, cannot write config.";
if (integrated_write_pid != -1) {
vty_out(vty, "%% %s\n", e_inprog);
return CMD_WARNING;
}
/* check that all daemons are up before clobbering config */
if (!check_all_up()) {
vty_out(vty, "%% %s\n", e_dmn);
/*
* vtysh interprets this return value to mean that it should
* not try to write the config itself
*/
return CMD_WARNING_CONFIG_FAILED;
}
fflush(stdout);
fflush(stderr);
/* need to temporarily block SIGCHLD because it could arrive between
* fork() call and setting the integrated_write_pid variable. This
* would mean the completion call gets lost and this hangs forever.
*/
sigemptyset(&oldmask);
sigemptyset(&sigmask);
sigaddset(&sigmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &sigmask, &oldmask);
child = fork();
if (child == -1) {
vty_out(vty, "%% configuration write fork() failed: %s.\n",
safe_strerror(errno));
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return CMD_WARNING;
}
if (child != 0) {
/* note: the VTY won't write a command return value to vtysh;
* the
* session temporarily enters an intentional "hang" state. This
* is
* to make sure latency in vtysh doing the config write (several
* seconds is not rare to see) does not interfere with
* watchfrr's
* supervisor job.
*
* The fd is duplicated here so we don't need to hold a vty
* pointer
* (which could become invalid in the meantime).
*/
integrated_write_pid = child;
integrated_result_fd = dup(vty->wfd);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return CMD_SUSPEND;
}
/* redirect stdout/stderr to vty session. Note vty->wfd is marked
* CLOEXEC, but dup2 will clear that flag. */
dup2(vty->wfd, 1);
dup2(vty->wfd, 2);
/* don't allow the user to pass parameters, we're root here!
* should probably harden vtysh at some point too... */
execl(VTYSH_BIN_PATH, "vtysh", "-w", NULL);
/* unbuffered write; we just messed with stdout... */
char msg[512];
snprintf(msg, sizeof(msg), "error executing %s: %s\n", VTYSH_BIN_PATH,
safe_strerror(errno));
write(1, msg, strlen(msg));
exit(1);
}
DEFUN_NOSH (show_debugging_watchfrr,
show_debugging_watchfrr_cmd,
"show debugging [watchfrr]",
SHOW_STR
DEBUG_STR
WATCHFRR_STR)
{
return CMD_SUCCESS;
}
void integrated_write_sigchld(int status)
{
uint8_t reply[4] = {0, 0, 0, CMD_WARNING};
if (WIFEXITED(status)) {
zlog_info("configuration write completed with exit code %d",
WEXITSTATUS(status));
reply[3] = WEXITSTATUS(status);
} else if (WIFSIGNALED(status)) {
zlog_warn("configuration write terminated by signal %d",
WTERMSIG(status));
} else {
zlog_warn("configuration write terminated");
}
if (reply[3] != CMD_SUCCESS) {
/* failure might be silent in vtysh without this */
static const char msg[] = "% Configuration write failed.\n";
write(integrated_result_fd, msg, strlen(msg));
}
/* don't care about failures here, if the connection is broken the
* return value will just be lost. */
write(integrated_result_fd, reply, sizeof(reply));
close(integrated_result_fd);
integrated_write_pid = -1;
}
void watchfrr_vty_init(void)
{
integrated_write_pid = -1;
install_element(ENABLE_NODE, &config_write_integrated_cmd);
install_element(ENABLE_NODE, &show_debugging_watchfrr_cmd);
install_element(CONFIG_NODE, &show_debugging_watchfrr_cmd);
}
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