7 files changed, 121 insertions, 2 deletions

diff --git a/README.md b/README.md
index 047c610..cfff5ed 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,7 @@ Tool for generating Elliptic curve domain parameters.
  - `-m / --memory=SIZE`		Use PARI stack of `SIZE` (can have suffix k/m/g).
  - `--threads=NUM`			Use `NUM` threads.
  - `--thread-stack=SIZE`	Use PARI stack of `SIZE` (per thread, can have suffix k/m/g).
+ - `--timeout=TIME`			Timeout computation of a curve parameter after `TIME` (can have suffix s/m/h/d).
 
 #### Examples
 
diff --git a/src/ecgen.c b/src/ecgen.c
index c7c5871..822b0af 100644
--- a/src/ecgen.c
+++ b/src/ecgen.c
@@ -29,6 +29,7 @@
 #include "invalid/invalid.h"
 #include "io/input.h"
 #include "io/output.h"
+#include "util/timeout.h"
 
 const char *argp_program_version =
     "ecgen 0.6.0\n"
@@ -50,6 +51,9 @@ bool init(void) {
 	// init PARI PRNG
 	if (!random_init()) return false;
 
+	// init the signal handlers, etc. for timeout handling
+	if (!timeout_init(&cfg)) return false;
+
 	// set datadir if specified
 	if (cfg.datadir) {
 		default0("datadir", cfg.datadir);
diff --git a/src/exhaustive/exhaustive.c b/src/exhaustive/exhaustive.c
index 5011490..b55bcca 100644
--- a/src/exhaustive/exhaustive.c
+++ b/src/exhaustive/exhaustive.c
@@ -15,6 +15,7 @@
 #include "gen/seed.h"
 #include "io/output.h"
 #include "util/memory.h"
+#include "util/timeout.h"
 
 exhaustive_t *exhaustive_new(void) { return try_calloc(sizeof(exhaustive_t)); }
 
@@ -230,7 +231,15 @@ int exhaustive_gen_retry(curve_t *curve, const config_t *cfg,
 
 		arg_t *arg = argss ? argss[state] : NULL;
 
-		int diff = generators[state](curve, cfg, arg, (offset_e)state);
+		int diff;
+		timeout_start(cfg->timeout) {
+			// This is not the best, but currently the best idea I have.
+			diff = start_offset - state;
+		}
+		else {
+			diff = generators[state](curve, cfg, arg, (offset_e)state);
+		}
+		timeout_stop();
 		int new_state = state + diff;
 		if (new_state < start_offset) new_state = start_offset;
 
diff --git a/src/io/cli.c b/src/io/cli.c
index 77f279f..74e6cc7 100644
--- a/src/io/cli.c
+++ b/src/io/cli.c
@@ -4,7 +4,6 @@
  */
 #include "cli.h"
 #include <string.h>
-#include <unistd.h>
 #include "exhaustive/ansi.h"
 
 char cli_doc[] =
@@ -34,6 +33,7 @@ enum opt_keys {
 	OPT_POINTS,
 	OPT_THREADS,
 	OPT_TSTACK,
+	OPT_TIMEOUT,
 	OPT_ANOMALOUS
 };
 
@@ -68,6 +68,7 @@ struct argp_option cli_options[] = {
 	{"memory",       OPT_MEMORY,    "SIZE",   0,                 "Use PARI stack of SIZE (can have suffix k/m/g).",                                       4},
 	{"threads",      OPT_THREADS,   "NUM",    0,                 "Use NUM threads.",                                                                      4},
 	{"thread-stack", OPT_TSTACK,    "SIZE",   0,                 "Use PARI stack of SIZE (per thread, can have suffix k/m/g).",                           4},
+	{"timeout",      OPT_TIMEOUT,   "TIME",   0,                 "Timeout computation of a curve parameter after TIME (can have suffix s/m/h/d).",        4},
 	{0}
 };
 // clang-format on
@@ -87,6 +88,21 @@ static unsigned long cli_parse_memory(const char *str) {
 	return read;
 }
 
+static unsigned long cli_parse_time(const char *str) {
+	char *suffix = NULL;
+	unsigned long read = strtoul(str, &suffix, 10);
+	if (suffix) {
+		if (*suffix == 'm' || *suffix == 'M') {
+			read *= 60;
+		} else if (*suffix == 'h' || *suffix == 'H') {
+			read *= 3600;
+		} else if (*suffix == 'd' || *suffix == 'D') {
+			read *= 86400;
+		}
+	}
+	return read;
+}
+
 error_t cli_parse(int key, char *arg, struct argp_state *state) {
 	config_t *cfg = state->input;
 
@@ -100,6 +116,9 @@ error_t cli_parse(int key, char *arg, struct argp_state *state) {
 		case OPT_TSTACK:
 			cfg->thread_memory = cli_parse_memory(arg);
 			break;
+		case OPT_TIMEOUT:
+			cfg->timeout = cli_parse_time(arg);
+			break;
 		case OPT_THREADS:
 			if (!strcmp(arg, "auto") || !strcmp(arg, "AUTO")) {
 				long nprocs = sysconf(_SC_NPROCESSORS_ONLN);
diff --git a/src/misc/config.h b/src/misc/config.h
index 5069881..fe792d5 100644
--- a/src/misc/config.h
+++ b/src/misc/config.h
@@ -58,6 +58,7 @@ typedef struct {
 	unsigned long memory;
 	unsigned long threads;
 	unsigned long thread_memory;
+	unsigned long timeout;
 
 	enum format_e format;
 	char *output;
diff --git a/src/util/timeout.c b/src/util/timeout.c
new file mode 100644
index 0000000..c9608a9
--- /dev/null
+++ b/src/util/timeout.c
@@ -0,0 +1,29 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+#include "timeout.h"
+
+__thread jmp_buf timeout_ptr;
+__thread bool timeout_in = false;
+__thread timer_t timeout_timer;
+
+void timeout_handle(int signum, siginfo_t *siginfo, void *other) {
+	sigset_t mask;
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGALRM);
+	sigprocmask(SIG_UNBLOCK, &mask, NULL);
+
+	if (timeout_in) siglongjmp(timeout_ptr, 1);
+}
+
+bool timeout_init(const config_t *cfg) {
+	struct sigaction new_action;
+
+	new_action.sa_sigaction = timeout_handle;
+	sigemptyset(&new_action.sa_mask);
+	new_action.sa_flags = SA_SIGINFO;
+
+	sigaction(SIGALRM, &new_action, NULL);
+	return true;
+}
\ No newline at end of file
diff --git a/src/util/timeout.h b/src/util/timeout.h
new file mode 100644
index 0000000..2b615bb
--- /dev/null
+++ b/src/util/timeout.h
@@ -0,0 +1,56 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+#ifndef ECGEN_TIMEOUT_H
+#define ECGEN_TIMEOUT_H
+
+#include <setjmp.h>
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+#include "io/output.h"
+#include "misc/config.h"
+
+extern __thread sigjmp_buf timeout_ptr;
+extern __thread bool timeout_in;
+extern __thread timer_t timeout_timer;
+
+/**
+ * @brief
+ */
+#define timeout_start(seconds)                                \
+	if ((seconds) != 0) {                                     \
+		struct sigevent sevp;                                 \
+		sevp.sigev_notify = SIGEV_THREAD_ID;                  \
+		sevp.sigev_signo = SIGALRM;                           \
+		sevp._sigev_un._tid = (__pid_t)syscall(SYS_gettid);   \
+                                                              \
+		timer_create(CLOCK_MONOTONIC, &sevp, &timeout_timer); \
+		struct itimerspec timer_time = {                      \
+		    .it_interval = {.tv_sec = 0, .tv_nsec = 0},       \
+		    .it_value = {.tv_sec = (seconds), .tv_nsec = 0}}; \
+		timer_settime(timeout_timer, 0, &timer_time, NULL);   \
+		timeout_in = true;                                    \
+	};                                                        \
+	if ((seconds) != 0 && sigsetjmp(timeout_ptr, 1) == 1)
+
+/**
+ * @brief
+ */
+#define timeout_stop()                   \
+	{                                    \
+		if (timeout_in) {                \
+			timeout_in = false;          \
+			timer_delete(timeout_timer); \
+		}                                \
+	}
+
+/**
+ * @brief
+ * @param cfg
+ * @return
+ */
+bool timeout_init(const config_t *cfg);
+
+#endif  // ECGEN_TIMEOUT_H