diff options
Diffstat (limited to 'src/plugins/fateshare/fateshare.c')
| -rw-r--r-- | src/plugins/fateshare/fateshare.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/src/plugins/fateshare/fateshare.c b/src/plugins/fateshare/fateshare.c new file mode 100644 index 00000000000..33ee167bce3 --- /dev/null +++ b/src/plugins/fateshare/fateshare.c @@ -0,0 +1,287 @@ +/* + * fateshare.c - skeleton vpp engine plug-in + * + * Copyright (c) 2022 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/vnet.h> +#include <vnet/plugin/plugin.h> +#include <fateshare/fateshare.h> + +#include <vlibapi/api.h> +#include <vlibmemory/api.h> +#include <vpp/app/version.h> +#include <stdbool.h> + +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/prctl.h> // prctl(), PR_SET_PDEATHSIG +#include <limits.h> + +fateshare_main_t fateshare_main; + +/* Action function shared between message handler and debug CLI */ + +static void +child_handler (int sig) +{ + pid_t pid; + int status; + fateshare_main_t *kmp = &fateshare_main; + + while ((pid = waitpid (-1, &status, WNOHANG)) > 0) + { + if (pid == kmp->monitor_pid) + { + clib_warning ("Monitor child %d exited with status %d!", pid, + status); + kmp->vlib_main->main_loop_exit_now = 1; + } + else + { + clib_warning ("child %d exited with status %d!", pid, status); + } + } +} + +clib_error_t * +launch_monitor (fateshare_main_t *kmp) +{ + clib_error_t *error = 0; + pid_t ppid_before_fork = getpid (); + pid_t cpid = fork (); + if (cpid == -1) + { + perror (0); + error = clib_error_return (0, "can not fork"); + goto done; + } + clib_warning ("fateshare about to launch monitor %v.", kmp->monitor_cmd); + int logfd = + open ((char *) kmp->monitor_logfile, O_APPEND | O_RDWR | O_CREAT, 0777); + if (logfd < 0) + { + error = clib_error_return (0, "can not open log file"); + goto done; + } + if (cpid) + { + /* parent */ + kmp->monitor_pid = cpid; + close (logfd); + return 0; + } + else + { + dup2 (logfd, 1); + dup2 (logfd, 2); + int r = prctl (PR_SET_PDEATHSIG, SIGTERM); + if (r == -1) + { + perror (0); + exit (1); + } + pid_t current_ppid = getppid (); + if (current_ppid != ppid_before_fork) + { + fprintf (stderr, "parent pid changed while starting (%d => %d)\n", + ppid_before_fork, current_ppid); + if (current_ppid == 1) + { + fprintf (stderr, "exiting.\n"); + exit (1); + } + } + + int r1 = setpgid (getpid (), 0); + if (r1 != 0) + { + perror ("setpgid error"); + exit (1); + } + + u8 *scmd = format (0, "%v\0", kmp->monitor_cmd); + u8 *logfile_base = format (0, "%v\0", kmp->monitor_logfile); + int fd = logfd - 1; + while (fd > 2) + { + close (fd); + fd--; + } + + fd = open ("/dev/null", O_RDONLY); + if (fd < 0) + { + exit (1); + } + dup2 (fd, 0); + + char *ppid_str = (char *) format (0, "%lld\0", current_ppid); + + char **argv = 0; + vec_validate (argv, vec_len (kmp->commands) + 3 - 1); + argv[0] = (void *) scmd; + argv[1] = ppid_str; + argv[2] = (char *) logfile_base; + int i; + vec_foreach_index (i, kmp->commands) + { + argv[3 + i] = (char *) kmp->commands[i]; + } + + int res = execv (argv[0], argv); + clib_warning ("ERROR during execve: %d", res); + perror ("execve"); + + exit (0); + } +done: + + return error; +} + +static clib_error_t * +fateshare_config (vlib_main_t *vm, unformat_input_t *input) +{ + fateshare_main_t *fmp = &fateshare_main; + u8 *command = 0; + u8 **new_command = 0; + clib_error_t *error = 0; + + /* unix config may make vpp fork, we want to run after that. */ + if ((error = vlib_call_config_function (vm, unix_config))) + return error; + + /* Defaults */ + while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) + { + if (unformat (input, "monitor %s", &fmp->monitor_cmd)) + { + clib_warning ("setting monitor to %v", fmp->monitor_cmd); + } + else if (unformat (input, "logfile %s", &fmp->monitor_logfile)) + { + clib_warning ("setting logfile to %v", fmp->monitor_logfile); + } + else if (unformat (input, "command %s", &command)) + { + vec_add2 (fmp->commands, new_command, 1); + *new_command = command; + } + else + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + + vec_add2 (fmp->commands, new_command, 1); + *new_command = 0; + + /* Establish handler. */ + struct sigaction sa; + sigemptyset (&sa.sa_mask); + sa.sa_flags = 0; + sa.sa_handler = child_handler; + + sigaction (SIGCHLD, &sa, NULL); + + if (fmp->monitor_cmd == 0) + { + char *p, path[PATH_MAX]; + int rv; + + /* find executable path */ + if ((rv = readlink ("/proc/self/exe", path, PATH_MAX - 1)) == -1) + return clib_error_return ( + 0, "could not stat /proc/self/exe - set monitor manually"); + + /* readlink doesn't provide null termination */ + path[rv] = 0; + + /* strip filename */ + if ((p = strrchr (path, '/')) == 0) + return clib_error_return ( + 0, "could not determine vpp directory - set monitor manually"); + *p = 0; + + fmp->monitor_cmd = format (0, "%s/vpp_fateshare_monitor\0", path); + } + if (fmp->monitor_logfile == 0) + { + fmp->monitor_logfile = + format (0, "/tmp/vpp-fateshare-monitor-log.txt\0"); + } + error = launch_monitor (fmp); + + return error; +} + +clib_error_t * +fateshare_init (vlib_main_t *vm) +{ + fateshare_main_t *kmp = &fateshare_main; + clib_error_t *error = 0; + + kmp->vlib_main = vm; + + return error; +} + +static clib_error_t * +fateshare_send_hup_fn (vlib_main_t *vm, unformat_input_t *input, + vlib_cli_command_t *cmd) +{ + clib_error_t *error = 0; + fateshare_main_t *kmp = &fateshare_main; + + if (kmp->monitor_pid) + { + int rc = kill (kmp->monitor_pid, SIGHUP); + if (rc) + { + error = clib_error_return ( + 0, "can not send signal to monitor process: %s", strerror (errno)); + } + } + else + { + error = clib_error_return (0, "can not find monitor process"); + } + + return error; +} + +VLIB_EARLY_CONFIG_FUNCTION (fateshare_config, "fateshare"); + +VLIB_INIT_FUNCTION (fateshare_init); + +VLIB_CLI_COMMAND (fateshare_restart_process_command, static) = { + .path = "fateshare restart-processes", + .short_help = "restart dependent processes", + .function = fateshare_send_hup_fn, +}; + +VLIB_PLUGIN_REGISTER () = { + .version = VPP_BUILD_VER, + .description = "Run child processes which will share fate with VPP, restart " + "them if they quit", + .default_disabled = 1, +}; + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |