diff options
Diffstat (limited to 'init/init.c')
| -rw-r--r-- | init/init.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/init/init.c b/init/init.c new file mode 100644 index 00000000..b3d33018 --- /dev/null +++ b/init/init.c @@ -0,0 +1,155 @@ +/* A minimalist init for the Hurd + + Copyright (C) 2013,14 Free Software Foundation, Inc. + This file is part of the GNU Hurd. + + The GNU Hurd 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, or (at your option) + any later version. + + The GNU Hurd 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 the Hurd. If not, see <http://www.gnu.org/licenses/>. */ + +#include <argp.h> +#include <error.h> +#include <hurd.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <version.h> + +const char *argp_program_version = STANDARD_HURD_VERSION (init); +static pid_t child_pid; +static int single; + +static struct argp_option +options[] = +{ + /* XXX: Currently, -s does nothing. */ + {"single-user", 's', NULL, 0, "Startup system in single-user mode", 0}, + {NULL, 'a', NULL, 0, "Ignored for compatibility with sysvinit", 0}, + {0} +}; + +static char doc[] = "A minimalist init for the Hurd"; + +static error_t +parse_opt (int key, char *arg, struct argp_state *state) +{ + switch (key) + { + case 's': + single = 1; + break; + + case 'a': + /* Ignored. */ + break; + + default: + return ARGP_ERR_UNKNOWN; + } + + return 0; +} + +void +sigchld_handler(int signal) +{ + /* A child died. Find its status. */ + int status; + pid_t pid; + + while (1) + { + pid = waitpid (WAIT_ANY, &status, WNOHANG | WUNTRACED); + if (pid <= 0) + break; /* No more children. */ + + /* Since we are init, orphaned processes get reparented to us and + alas, all our adopted children eventually die. Woe is us. We + just need to reap the zombies to relieve the proc server of + its burden, and then we can forget about the little varmints. */ + + if (pid == child_pid) + { + /* The big magilla bit the dust. */ + child_pid = -1; + + char *desc = NULL; + if (WIFSIGNALED (status)) + asprintf (&desc, "terminated abnormally (%s)", + strsignal (WTERMSIG (status))); + else if (WIFSTOPPED (status)) + asprintf (&desc, "stopped abnormally (%s)", + strsignal (WTERMSIG (status))); + else if (WEXITSTATUS (status) == 0) + desc = strdup ("finished"); + else + asprintf (&desc, "exited with status %d", + WEXITSTATUS (status)); + + error (0, 0, "child %s", desc); + free (desc); + + /* XXX: launch emergency shell. */ + error (23, 0, "panic!!"); + } + } +} + +int +main (int argc, char **argv) +{ + struct argp argp = + { + .options = options, + .parser = parse_opt, + .doc = doc, + }; + argp_parse (&argp, argc, argv, 0, 0, 0); + + if (getpid () != 1) + error (1, 0, "can only be run as PID 1"); + + struct sigaction sa; + sa.sa_handler = SIG_IGN; + sa.sa_flags = 0; + sigemptyset (&sa.sa_mask); + + sigaction (SIGHUP, &sa, NULL); + sigaction (SIGINT, &sa, NULL); + sigaction (SIGQUIT, &sa, NULL); + sigaction (SIGTERM, &sa, NULL); + sigaction (SIGUSR1, &sa, NULL); + sigaction (SIGUSR2, &sa, NULL); + sigaction (SIGTSTP, &sa, NULL); + + sa.sa_handler = sigchld_handler; + sa.sa_flags |= SA_RESTART; + sigaction (SIGCHLD, &sa, NULL); + + char *args[] = { "/etc/hurd/runsystem.hurd", NULL }; + + switch (child_pid = fork ()) + { + case -1: + error (1, errno, "failed to fork"); + case 0: + execv (args[0], args); + error (2, errno, "failed to execv child"); + } + + select (0, NULL, NULL, NULL, NULL); + /* Not reached. */ + return 0; +} |