persistent keepalive: add userspace support

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

src/config.c

@@ -182,6 +182,27 @@ static inline bool parse_endpoint(struct sockaddr_storage *endpoint, const char
 	return true;
 }
 
+static inline bool parse_persistent_keepalive(__u16 *interval, const char *value)
+{
+	unsigned long ret;
+	char *end;
+
+	if (!strcasecmp(value, "off")) {
+		*interval = 0;
+		return true;
+	}
+
+	ret = strtoul(value, &end, 10);
+	if (!*value || *value == '-' || *end || (ret && (ret < 10 || ret > 3600))) {
+		fprintf(stderr, "The persistent keepalive interval must be 0/off or 10-3600. Found: `%s`\n", value);
+		return false;
+	}
+
+	*interval = (__u16)ret;
+	return true;
+}
+
+
 static inline bool parse_ipmasks(struct inflatable_device *buf, size_t peer_offset, const char *value)
 {
 	struct wgpeer *peer;
@@ -263,6 +284,7 @@ static bool process_line(struct config_ctx *ctx, const char *line)
 		ctx->is_peer_section = true;
 		ctx->is_device_section = false;
 		peer_from_offset(ctx->buf.dev, ctx->peer_offset)->replace_ipmasks = true;
+		peer_from_offset(ctx->buf.dev, ctx->peer_offset)->persistent_keepalive_interval = (__u16)-1;
 		return true;
 	}
 
@@ -288,6 +310,8 @@ static bool process_line(struct config_ctx *ctx, const char *line)
 			ret = parse_key(peer_from_offset(ctx->buf.dev, ctx->peer_offset)->public_key, value);
 		else if (key_match("AllowedIPs"))
 			ret = parse_ipmasks(&ctx->buf, ctx->peer_offset, value);
+		else if (key_match("PersistentKeepalive"))
+			ret = parse_persistent_keepalive(&peer_from_offset(ctx->buf.dev, ctx->peer_offset)->persistent_keepalive_interval, value);
 		else
 			goto error;
 	} else
@@ -476,6 +500,7 @@ bool config_read_cmd(struct wgdevice **device, char *argv[], int argc)
 				perror("use_space");
 				goto error;
 			}
+			peer_from_offset(buf.dev, peer_offset)->persistent_keepalive_interval = (__u16)-1;
 			++buf.dev->num_peers;
 			if (!parse_key(peer_from_offset(buf.dev, peer_offset)->public_key, argv[1]))
 				goto error;
@@ -501,6 +526,11 @@ bool config_read_cmd(struct wgdevice **device, char *argv[], int argc)
 			free(line);
 			argv += 2;
 			argc -= 2;
+		} else if (!strcmp(argv[0], "persistent-keepalive") && argc >= 2 && buf.dev->num_peers) {
+			if (!parse_persistent_keepalive(&peer_from_offset(buf.dev, peer_offset)->persistent_keepalive_interval, argv[1]))
+				goto error;
+			argv += 2;
+			argc -= 2;
 		} else {
 			fprintf(stderr, "Invalid argument: %s\n", argv[0]);
 			goto error;

src/set.c

@@ -13,7 +13,7 @@ int set_main(int argc, char *argv[])
 	int ret = 1;
 
 	if (argc < 3) {
-		fprintf(stderr, "Usage: %s %s <interface> [listen-port <port>] [private-key <file path>] [peer <base64 public key> [remove] [endpoint <ip>:<port>] [allowed-ips <ip1>/<cidr1>[,<ip2>/<cidr2>]...] ]...\n", PROG_NAME, argv[0]);
+		fprintf(stderr, "Usage: %s %s <interface> [listen-port <port>] [private-key <file path>] [peer <base64 public key> [remove] [endpoint <ip>:<port>] [persistent-keepalive <interval seconds>] [allowed-ips <ip1>/<cidr1>[,<ip2>/<cidr2>]...] ]...\n", PROG_NAME, argv[0]);
 		return 1;
 	}
 

src/show.c

@@ -121,13 +121,11 @@ static char *endpoint(const struct sockaddr_storage *addr)
 	return buf;
 }
 
-static char *ago(const struct timeval *t)
+static size_t pretty_time(char *buf, const size_t len, unsigned long long left)
 {
-	static char buf[1024];
-	unsigned long long left, years, days, hours, minutes, seconds;
 	size_t offset = 0;
+	unsigned long long years, days, hours, minutes, seconds;
 
-	left = time(NULL) - t->tv_sec;
 	years = left / (365 * 24 * 60 * 60);
 	left = left % (365 * 24 * 60 * 60);
 	days = left / (24 * 60 * 60);
@@ -138,15 +136,25 @@ static char *ago(const struct timeval *t)
 	seconds = left % 60;
 
 	if (years)
-		offset += snprintf(buf + offset, sizeof(buf) - offset, "%s%llu " TERMINAL_FG_CYAN "year%s" TERMINAL_RESET, offset ? ", " : "", years, years == 1 ? "" : "s");
+		offset += snprintf(buf + offset, len - offset, "%s%llu " TERMINAL_FG_CYAN "year%s" TERMINAL_RESET, offset ? ", " : "", years, years == 1 ? "" : "s");
 	if (days)
-		offset += snprintf(buf + offset, sizeof(buf) - offset, "%s%llu " TERMINAL_FG_CYAN  "day%s" TERMINAL_RESET, offset ? ", " : "", days, days == 1 ? "" : "s");
+		offset += snprintf(buf + offset, len - offset, "%s%llu " TERMINAL_FG_CYAN  "day%s" TERMINAL_RESET, offset ? ", " : "", days, days == 1 ? "" : "s");
 	if (hours)
-		offset += snprintf(buf + offset, sizeof(buf) - offset, "%s%llu " TERMINAL_FG_CYAN  "hour%s" TERMINAL_RESET, offset ? ", " : "", hours, hours == 1 ? "" : "s");
+		offset += snprintf(buf + offset, len - offset, "%s%llu " TERMINAL_FG_CYAN  "hour%s" TERMINAL_RESET, offset ? ", " : "", hours, hours == 1 ? "" : "s");
 	if (minutes)
-		offset += snprintf(buf + offset, sizeof(buf) - offset, "%s%llu " TERMINAL_FG_CYAN "minute%s" TERMINAL_RESET, offset ? ", " : "", minutes, minutes == 1 ? "" : "s");
+		offset += snprintf(buf + offset, len - offset, "%s%llu " TERMINAL_FG_CYAN "minute%s" TERMINAL_RESET, offset ? ", " : "", minutes, minutes == 1 ? "" : "s");
 	if (seconds)
-		offset += snprintf(buf + offset, sizeof(buf) - offset, "%s%llu " TERMINAL_FG_CYAN  "second%s" TERMINAL_RESET, offset ? ", " : "", seconds, seconds == 1 ? "" : "s");
+		offset += snprintf(buf + offset, len - offset, "%s%llu " TERMINAL_FG_CYAN  "second%s" TERMINAL_RESET, offset ? ", " : "", seconds, seconds == 1 ? "" : "s");
+
+	return offset;
+}
+
+static char *ago(const struct timeval *t)
+{
+	static char buf[1024];
+	size_t offset;
+
+	offset = pretty_time(buf, sizeof(buf), time(NULL) - t->tv_sec);
 	if (offset)
 		snprintf(buf + offset, sizeof(buf) - offset, " ago");
 	else
@@ -155,6 +163,13 @@ static char *ago(const struct timeval *t)
 	return buf;
 }
 
+static char *every(uint16_t seconds)
+{
+	static char buf[1024] = "every ";
+	pretty_time(buf + strlen("every "), sizeof(buf) - strlen("every "), seconds);
+	return buf;
+}
+
 static char *bytes(uint64_t b)
 {
 	static char buf[1024];
@@ -176,7 +191,7 @@ static char *bytes(uint64_t b)
 static const char *COMMAND_NAME = NULL;
 static void show_usage(void)
 {
-	fprintf(stderr, "Usage: %s %s { <interface> | all | interfaces } [public-key | private-key | preshared-key | listen-port | peers | endpoints | allowed-ips | latest-handshake | bandwidth]\n", PROG_NAME, COMMAND_NAME);
+	fprintf(stderr, "Usage: %s %s { <interface> | all | interfaces } [public-key | private-key | preshared-key | listen-port | peers | endpoints | allowed-ips | latest-handshake | bandwidth | persistent-keepalive]\n", PROG_NAME, COMMAND_NAME);
 }
 
 static void pretty_print(struct wgdevice *device)
@@ -216,6 +231,8 @@ static void pretty_print(struct wgdevice *device)
 			terminal_printf("%s received, ", bytes(peer->rx_bytes));
 			terminal_printf("%s sent\n", bytes(peer->tx_bytes));
 		}
+		if (peer->persistent_keepalive_interval)
+			terminal_printf("  " TERMINAL_BOLD "persistent keepalive" TERMINAL_RESET ": %s\n", every(peer->persistent_keepalive_interval));
 		if (i + 1 < device->num_peers)
 			terminal_printf("\n");
 	}
@@ -275,6 +292,15 @@ static bool ugly_print(struct wgdevice *device, const char *param, bool with_int
 				printf("%s\t", device->interface);
 			printf("%s\t%" PRIu64 "\t%" PRIu64 "\n", key(peer->public_key), (uint64_t)peer->rx_bytes, (uint64_t)peer->tx_bytes);
 		}
+	} else if (!strcmp(param, "persistent-keepalive")) {
+		for_each_wgpeer(device, peer, i) {
+			if (with_interface)
+				printf("%s\t", device->interface);
+			if (peer->persistent_keepalive_interval)
+				printf("%s\t%u\n", key(peer->public_key), peer->persistent_keepalive_interval);
+			else
+				printf("%s\toff\n", key(peer->public_key));
+		}
 	} else if (!strcmp(param, "peers")) {
 		for_each_wgpeer(device, peer, i) {
 			if (with_interface)

src/showconf.c

@@ -91,6 +91,9 @@ int showconf_main(int argc, char *argv[])
 			}
 		}
 
+		if (peer->persistent_keepalive_interval)
+			printf("PersistentKeepalive = %u\n", peer->persistent_keepalive_interval);
+
 		if (i + 1 < device->num_peers)
 			printf("\n");
 	}