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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-12-25 01:08:58 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-12-25 01:08:58 +0000
commitec5631b6d697895ff4f1f750840326f9f035df96 (patch)
tree041d1134275f62d9887c1684d9ed51c043ca7454 /init
parent7b55c7f97d1aec5a34a33b8ce6412f2d62f7122a (diff)
downloadbusybox-ec5631b6d697895ff4f1f750840326f9f035df96.tar.gz
busybox-ec5631b6d697895ff4f1f750840326f9f035df96.tar.bz2
init: add FEATURE_KILL_REMOVED (Eugene Bordenkircher <eugebo@gmail.com>)
init: slight size optimization
Diffstat (limited to 'init')
-rw-r--r--init/Config.in20
-rw-r--r--init/init.c117
2 files changed, 74 insertions, 63 deletions
diff --git a/init/Config.in b/init/Config.in
index 318f523a0..1084de905 100644
--- a/init/Config.in
+++ b/init/Config.in
@@ -27,6 +27,26 @@ config FEATURE_USE_INITTAB
help
Allow init to read an inittab file when the system boot.
+config FEATURE_KILL_REMOVED
+ bool "Support killing processes that have been removed from inittab"
+ default y
+ depends on FEATURE_USE_INITTAB
+ help
+ When respawn entries are removed from inittab and a SIGHUP is
+ sent to init, this feature will kill the processes that have
+ been removed.
+
+config FEATURE_KILL_DELAY
+ int "How long to wait between TERM and KILL (0 - send TERM only)"
+ range 0 1024
+ default 0
+ depends on FEATURE_KILL_REMOVED
+ help
+ With nonzero setting, init sends TERM, forks, child waits N
+ seconds, sends KILL and exits. Setting it too high is unwise
+ (child will hang around for too long and can actually kill
+ wrong process!)
+
config FEATURE_INIT_SCTTY
bool "Support running commands with a controlling-tty"
default n
diff --git a/init/init.c b/init/init.c
index baa5a5000..e6581880c 100644
--- a/init/init.c
+++ b/init/init.c
@@ -738,21 +738,8 @@ static void delete_init_action(struct init_action *action)
static void parse_inittab(void)
{
#if ENABLE_FEATURE_USE_INITTAB
- static const char actions[] =
- STR_SYSINIT "sysinit\0"
- STR_RESPAWN "respawn\0"
- STR_ASKFIRST "askfirst\0"
- STR_WAIT "wait\0"
- STR_ONCE "once\0"
- STR_CTRLALTDEL "ctrlaltdel\0"
- STR_SHUTDOWN "shutdown\0"
- STR_RESTART "restart\0"
- ;
-
FILE *file;
- char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
- char tmpConsole[CONSOLE_NAME_SIZE];
- char *id, *runlev, *action, *command, *eol;
+ char buf[INIT_BUFFS_SIZE];
file = fopen(INITTAB, "r");
if (file == NULL) {
@@ -780,57 +767,43 @@ static void parse_inittab(void)
}
while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
+ static const char actions[] =
+ STR_SYSINIT "sysinit\0"
+ STR_RESPAWN "respawn\0"
+ STR_ASKFIRST "askfirst\0"
+ STR_WAIT "wait\0"
+ STR_ONCE "once\0"
+ STR_CTRLALTDEL "ctrlaltdel\0"
+ STR_SHUTDOWN "shutdown\0"
+ STR_RESTART "restart\0"
+ ;
+ char tmpConsole[CONSOLE_NAME_SIZE];
+ char *id, *runlev, *action, *command;
const char *a;
/* Skip leading spaces */
- for (id = buf; *id == ' ' || *id == '\t'; id++);
-
+ id = skip_whitespace(buf);
/* Skip the line if it's a comment */
if (*id == '#' || *id == '\n')
continue;
+ /* Trim the trailing '\n' */
+ *strchrnul(id, '\n') = '\0';
- /* Trim the trailing \n */
- //XXX: chomp() ?
- eol = strrchr(id, '\n');
- if (eol != NULL)
- *eol = '\0';
-
- /* Keep a copy around for posterity's sake (and error msgs) */
- strcpy(lineAsRead, buf);
-
- /* Separate the ID field from the runlevels */
+ /* Line is: "id:runlevel_ignored:action:command" */
runlev = strchr(id, ':');
- if (runlev == NULL || *(runlev + 1) == '\0') {
- message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
- continue;
- } else {
- *runlev = '\0';
- ++runlev;
- }
-
- /* Separate the runlevels from the action */
- action = strchr(runlev, ':');
- if (action == NULL || *(action + 1) == '\0') {
- message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
- continue;
- } else {
- *action = '\0';
- ++action;
- }
-
- /* Separate the action from the command */
- command = strchr(action, ':');
- if (command == NULL || *(command + 1) == '\0') {
- message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
- continue;
- } else {
- *command = '\0';
- ++command;
- }
-
- /* Ok, now process it */
+ if (runlev == NULL /*|| runlev[1] == '\0' - not needed */)
+ goto bad_entry;
+ action = strchr(runlev + 1, ':');
+ if (action == NULL /*|| action[1] == '\0' - not needed */)
+ goto bad_entry;
+ command = strchr(action + 1, ':');
+ if (command == NULL || command[1] == '\0')
+ goto bad_entry;
+
+ *command = '\0'; /* action => ":action\0" now */
for (a = actions; a[0]; a += strlen(a) + 1) {
- if (strcmp(a + 1, action) == 0) {
+ if (strcmp(a + 1, action + 1) == 0) {
+ *runlev = '\0';
if (*id != '\0') {
if (strncmp(id, "/dev/", 5) == 0)
id += 5;
@@ -839,14 +812,15 @@ static void parse_inittab(void)
sizeof(tmpConsole) - 5);
id = tmpConsole;
}
- new_init_action((uint8_t)a[0], command, id);
- break;
+ new_init_action((uint8_t)a[0], command + 1, id);
+ goto next_line;
}
}
- if (!a[0]) {
- /* Choke on an unknown action */
- message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
- }
+ *command = ':';
+ /* Choke on an unknown action */
+ bad_entry:
+ message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", id);
+ next_line: ;
}
fclose(file);
#endif /* FEATURE_USE_INITTAB */
@@ -860,12 +834,29 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED)
message(L_LOG, "reloading /etc/inittab");
/* disable old entrys */
- for (a = init_action_list; a; a = a->next ) {
+ for (a = init_action_list; a; a = a->next) {
a->action = ONCE;
}
parse_inittab();
+#if ENABLE_FEATURE_KILL_REMOVED
+ for (a = init_action_list; a; a = a->next) {
+ pid_t pid = a->pid;
+ if ((a->action & ONCE) && pid != 0) {
+ /* Be nice and send SIGTERM first */
+ kill(pid, SIGTERM);
+#if CONFIG_FEATURE_KILL_DELAY
+ if (fork() == 0) { /* child */
+ sleep(CONFIG_FEATURE_KILL_DELAY);
+ kill(pid, SIGKILL);
+ _exit(0);
+ }
+#endif
+ }
+ }
+#endif /* FEATURE_KILL_REMOVED */
+
/* remove unused entrys */
for (a = init_action_list; a; a = tmp) {
tmp = a->next;