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-rw-r--r--CHANGELOG1
-rw-r--r--etc/tlsdated.conf3
-rw-r--r--man/tlsdated.conf.56
-rw-r--r--src/tlsdate.h6
-rw-r--r--src/tlsdated-unittest.c14
-rw-r--r--src/tlsdated.c77
-rw-r--r--src/util.c31
-rw-r--r--src/util.h4
8 files changed, 75 insertions, 67 deletions
diff --git a/CHANGELOG b/CHANGELOG
index fbe7a83..c408a15 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -15,6 +15,7 @@
Add Mac OS X 10.8.3 support
Extensive setup/install documentation is now present in INSTALL for most OSes
Add DragonFly BSD 3.3 support
+ Refactored subprocess watching.
0.0.6 Mon 18 Feb, 2013
Ensure that tlsdate compiles with g++ by explicit casting rather than
implicit casting by whatever compiler is compiling tlsdate.
diff --git a/etc/tlsdated.conf b/etc/tlsdated.conf
index 9f9b43e..c6dbbf0 100644
--- a/etc/tlsdated.conf
+++ b/etc/tlsdated.conf
@@ -12,8 +12,7 @@ should-netlink yes
should-save-disk yes
should-sync-hwclock yes
steady-state-interval 86400
-subprocess-tries 10
-subprocess-wait-between-tries 3
+subprocess-timeout 30
verbose yes
wait-between-tries 10
diff --git a/man/tlsdated.conf.5 b/man/tlsdated.conf.5
index 13fb153..79ed27a 100644
--- a/man/tlsdated.conf.5
+++ b/man/tlsdated.conf.5
@@ -42,10 +42,8 @@ at exit.
If enabled, set the hwclock to the fetched time.
.IP "steady-state-interval [int]"
Check at least once this many seconds when in steady state.
-.IP "subprocess-tries [int]"
-How many times to try waiting for the subprocess.
-.IP "subprocess-wait-between-tries [int]"
-How many seconds to wait between each attempt to wait for the subprocess.
+.IP "subprocess-timeout [int]"
+How many seconds to wait for the subprocess to exit.
.IP "verbose [bool]"
If enabled, tlsdated will be annoyingly verbose in syslog and on stdout.
.IP "wait-between-tries [int]"
diff --git a/src/tlsdate.h b/src/tlsdate.h
index 5b24980..978396d 100644
--- a/src/tlsdate.h
+++ b/src/tlsdate.h
@@ -33,8 +33,7 @@
/* tlsdated magic numbers */
#define MAX_TRIES 10
#define WAIT_BETWEEN_TRIES 10
-#define SUBPROCESS_TRIES 10
-#define SUBPROCESS_WAIT_BETWEEN_TRIES 3
+#define SUBPROCESS_TIMEOUT 30
#define STEADY_STATE_INTERVAL 86400
#define DEFAULT_SYNC_HWCLOCK 1
#define DEFAULT_LOAD_FROM_DISK 1
@@ -67,8 +66,7 @@ struct opts {
int max_tries;
int min_steady_state_interval;
int wait_between_tries;
- int subprocess_tries;
- int subprocess_wait_between_tries;
+ int subprocess_timeout;
int steady_state_interval;
const char *base_path;
char **base_argv;
diff --git a/src/tlsdated-unittest.c b/src/tlsdated-unittest.c
index cb30313..5baca13 100644
--- a/src/tlsdated-unittest.c
+++ b/src/tlsdated-unittest.c
@@ -118,8 +118,7 @@ TEST(tlsdate_tests) {
memset(&opts, 0, sizeof(opts));
opts.sources = &source;
opts.base_argv = args;
- opts.subprocess_tries = 2;
- opts.subprocess_wait_between_tries = 1;
+ opts.subprocess_timeout = 1;
extern char **environ;
EXPECT_EQ(1, tlsdate(&opts, environ));
args[0] = "/bin/false";
@@ -129,7 +128,7 @@ TEST(tlsdate_tests) {
args[0] = "src/test/sleep-wrap";
args[1] = "3";
EXPECT_EQ(-1, tlsdate(&opts, environ));
- opts.subprocess_wait_between_tries = 5;
+ opts.subprocess_timeout = 5;
EXPECT_EQ(0, tlsdate(&opts, environ));
}
@@ -167,8 +166,7 @@ TEST(rotate_hosts) {
memset(&opts, 0, sizeof(opts));
opts.sources = &s1;
opts.base_argv = args;
- opts.subprocess_tries = 2;
- opts.subprocess_wait_between_tries = 1;
+ opts.subprocess_timeout = 2;
extern char **environ;
EXPECT_EQ(1, tlsdate(&opts, environ));
EXPECT_EQ(2, tlsdate(&opts, environ));
@@ -188,8 +186,7 @@ TEST(proxy_override) {
memset(&opts, 0, sizeof(opts));
opts.sources = &s1;
opts.base_argv = args;
- opts.subprocess_tries = 2;
- opts.subprocess_wait_between_tries = 1;
+ opts.subprocess_timeout = 2;
extern char **environ;
EXPECT_EQ(1, tlsdate(&opts, environ));
s1.proxy = "socks5://bad.proxy";
@@ -210,8 +207,7 @@ TEST(tlsdate_args) {
memset(&opts, 0, sizeof(opts));
opts.sources = &s1;
opts.base_argv = args;
- opts.subprocess_tries = 2;
- opts.subprocess_wait_between_tries = 1;
+ opts.subprocess_timeout = 2;
opts.leap = 1;
verbose = 1;
EXPECT_EQ(9, tlsdate(&opts, environ));
diff --git a/src/tlsdated.c b/src/tlsdated.c
index ef9fe68..7816223 100644
--- a/src/tlsdated.c
+++ b/src/tlsdated.c
@@ -106,43 +106,35 @@ int
tlsdate (struct opts *opts, char *envp[])
{
pid_t pid;
+ pid_t exited;
+ int status;
+
build_argv(opts);
-
- if ((pid = fork ()) > 0)
- {
- /*
- * We launched tlsdate; wait for up to kMaxTries intervals of
- * kWaitBetweenTries for it to exit, then kill it if it still
- * hasn't.
- */
- int status = -1;
- int i = 0;
- for (i = 0; i < opts->subprocess_tries; ++i)
+
+ pid = fork();
+ if (pid < 0)
{
- info ("wait for child attempt %d", i);
- if (waitpid (-1, &status, WNOHANG) > 0)
- break;
- sleep (opts->subprocess_wait_between_tries);
+ pinfo("fork() failed");
+ return -1;
}
- if (i == opts->subprocess_tries)
+ else if (pid == 0)
{
- error ("child hung?");
- kill (pid, SIGKILL);
- /* still have to wait() so we don't leak the child. */
- wait (&status);
+ execve(opts->argv[0], opts->argv, envp);
+ pinfo("execve() failed");
+ exit(1);
+ }
+
+ exited = wait_with_timeout(&status, opts->subprocess_timeout);
+ info("child %d exited with %d", exited, status);
+
+ if (exited == -ETIMEDOUT)
+ {
+ kill(pid, SIGKILL);
+ wait(&status);
return -1;
}
- info ("child exited with %d", status);
- return WIFEXITED (status) ? WEXITSTATUS (status) : -1;
- }
- else if (pid < 0)
- {
- pinfo ("fork() failed");
- return -1;
- }
- execve (opts->argv[0], opts->argv, envp);
- pinfo ("execve() failed");
- exit (1);
+
+ return WIFEXITED(status) ? WEXITSTATUS(status) : -1;
}
/*
@@ -394,8 +386,7 @@ set_conf_defaults(struct opts *opts)
opts->max_tries = MAX_TRIES;
opts->min_steady_state_interval = STEADY_STATE_INTERVAL;
opts->wait_between_tries = WAIT_BETWEEN_TRIES;
- opts->subprocess_tries = SUBPROCESS_TRIES;
- opts->subprocess_wait_between_tries = SUBPROCESS_WAIT_BETWEEN_TRIES;
+ opts->subprocess_timeout = SUBPROCESS_TIMEOUT;
opts->steady_state_interval = STEADY_STATE_INTERVAL;
opts->base_path = kCacheDir;
opts->base_argv = kDefaultArgv;
@@ -418,7 +409,7 @@ parse_argv(struct opts *opts, int argc, char *argv[])
{
int opt;
- while ((opt = getopt (argc, argv, "hwrpt:d:T:D:c:a:lsvm:j:f:x:")) != -1)
+ while ((opt = getopt (argc, argv, "hwrpt:d:c:a:lsvm:j:f:x:")) != -1)
{
switch (opt)
{
@@ -437,12 +428,6 @@ parse_argv(struct opts *opts, int argc, char *argv[])
case 'd':
opts->wait_between_tries = atoi (optarg);
break;
- case 'T':
- opts->subprocess_tries = atoi (optarg);
- break;
- case 'D':
- opts->subprocess_wait_between_tries = atoi (optarg);
- break;
case 'c':
opts->base_path = optarg;
break;
@@ -572,10 +557,8 @@ load_conf(struct opts *opts)
opts->min_steady_state_interval = atoi (e->value);
} else if (!strcmp (e->key, "wait-between-tries") && e->value) {
opts->wait_between_tries = atoi (e->value);
- } else if (!strcmp (e->key, "subprocess-tries") && e->value) {
- opts->subprocess_tries = atoi (e->value);
- } else if (!strcmp (e->key, "subprocess-wait-between-tries") && e->value) {
- opts->subprocess_wait_between_tries = atoi (e->value);
+ } else if (!strcmp (e->key, "subprocess-timeout") && e->value) {
+ opts->subprocess_timeout = atoi (e->value);
} else if (!strcmp (e->key, "steady-state-interval") && e->value) {
opts->steady_state_interval = atoi (e->value);
} else if (!strcmp (e->key, "base-path") && e->value) {
@@ -611,10 +594,8 @@ check_conf(struct opts *opts)
fatal ("-t argument must be nonzero");
if (!opts->wait_between_tries)
fatal ("-d argument must be nonzero");
- if (!opts->subprocess_tries)
- fatal ("-T argument must be nonzero");
- if (!opts->subprocess_wait_between_tries)
- fatal ("-D argument must be nonzero");
+ if (!opts->subprocess_timeout)
+ fatal ("subprocess timeout must be nonzero");
if (!opts->steady_state_interval)
fatal ("-a argument must be nonzero");
if (snprintf (timestamp_path, sizeof (timestamp_path), "%s/timestamp",
diff --git a/src/util.c b/src/util.c
index 68f3a98..30a0f44 100644
--- a/src/util.c
+++ b/src/util.c
@@ -9,9 +9,11 @@
#include <grp.h>
#include <pwd.h>
+#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
+#include <sys/wait.h>
#include <syslog.h>
#include <unistd.h>
@@ -101,3 +103,32 @@ drop_privs_to (const char *user, const char *group)
#endif
}
+pid_t
+wait_with_timeout(int *status, int timeout_secs)
+{
+ int st = 0;
+ pid_t exited;
+ /* synthesize waiting with a timeout by using a helper process. We
+ * launch a child process that will exit in |timeout_secs|, guaranteeing
+ * that wait() will return by then. */
+ pid_t helper = fork();
+ if (helper < 0)
+ return helper;
+ if (helper == 0)
+ {
+ sleep(timeout_secs);
+ exit(0);
+ }
+
+ /* use temporary status to avoid touching it if we do ETIMEDOUT */
+ exited = wait(&st);
+ if (exited == helper)
+ /* helper exited before any other child did */
+ return -ETIMEDOUT;
+
+ /* a real child process exited - don't leak the helper */
+ kill(helper, SIGKILL);
+ waitpid(helper, NULL, 0);
+ *status = st;
+ return exited;
+}
diff --git a/src/util.h b/src/util.h
index bfd61dd..2632933 100644
--- a/src/util.h
+++ b/src/util.h
@@ -37,4 +37,8 @@ static inline int min(int x, int y) { return x < y ? x : y; }
void drop_privs_to (const char *user, const char *group);
+/* like wait(), but with a timeout. Returns ordinary fork() error codes, or
+ * ETIMEDOUT. */
+pid_t wait_with_timeout(int *status, int timeout_secs);
+
#endif /* !UTIL_H */
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-08 20:04:11 +0000