resolver: write whole hostname instead of a pointer to the resolver pipe

Shouldn't make a difference, but feels cleaner now, and silences a
clang-analyzer warning.

3 files changed, 40 insertions, 24 deletions

diff --git a/src/fastd.c b/src/fastd.c
index 18f9d96..e48bb8a 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -851,19 +851,25 @@ static void handle_socket(fastd_context_t *ctx, fastd_socket_t *sock) {
 static void handle_resolv_returns(fastd_context_t *ctx) {
 	fastd_resolve_return_t resolve_return;
 
-	if (read(ctx->resolverfd, &resolve_return, sizeof(resolve_return)) < 0) {
+	while (read(ctx->resolverfd, &resolve_return, sizeof(resolve_return)) < 0) {
 		if (errno != EINTR)
-			pr_warn(ctx, "read: %s", strerror(errno));
+			exit_errno(ctx, "handle_resolv_return: read");
+	}
 
-		return;
+	char hostname[resolve_return.hostname_len+1];
+	while (read(ctx->resolverfd, hostname, resolve_return.hostname_len) < 0) {
+		if (errno != EINTR)
+			exit_errno(ctx, "handle_resolv_return: read");
 	}
 
+	hostname[resolve_return.hostname_len] = 0;
+
 	fastd_peer_t *peer;
 	for (peer = ctx->peers; peer; peer = peer->next) {
 		if (!peer->config)
 			continue;
 
-		if (!strequal(peer->config->hostname, resolve_return.hostname))
+		if (!strequal(peer->config->hostname, hostname))
 			continue;
 
 		if (!fastd_peer_config_matches_dynamic(peer->config, &resolve_return.constraints))
@@ -875,13 +881,11 @@ static void handle_resolv_returns(fastd_context_t *ctx) {
 			send_handshake(ctx, peer);
 		}
 		else {
-			pr_warn(ctx, "hostname `%s' resolved to address %I which is used by a fixed peer", resolve_return.hostname, &resolve_return.addr);
+			pr_warn(ctx, "hostname `%s' resolved to address %I which is used by a fixed peer", hostname, &resolve_return.addr);
 			fastd_task_schedule_handshake(ctx, peer, fastd_rand(ctx, 17500, 22500));
 		}
 		break;
 	}
-
-	free(resolve_return.hostname);
 }
 
 static inline void handle_socket_error(fastd_context_t *ctx, fastd_socket_t *sock) {
diff --git a/src/fastd.h b/src/fastd.h
index 9223ffe..b2b7de7 100644
--- a/src/fastd.h
+++ b/src/fastd.h
@@ -109,10 +109,10 @@ union fastd_peer_address {
 };
 
 struct fastd_resolve_return {
-	char *hostname;
-	fastd_peer_address_t constraints;
-
 	fastd_peer_address_t addr;
+
+	fastd_peer_address_t constraints;
+	size_t hostname_len;
 };
 
 struct fastd_log_file {
diff --git a/src/resolve.c b/src/resolve.c
index b1ef696..02a986d 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -69,25 +69,32 @@ static void* resolve_peer(void *varg) {
 		error = true;
 	}
 
-	fastd_resolve_return_t ret;
-	memset(&ret, 0, sizeof(ret));
+	size_t hostname_len = strlen(arg->hostname);
+	char buf[sizeof(fastd_resolve_return_t) + hostname_len];
 
-	ret.hostname = arg->hostname;
-	ret.constraints = arg->constraints;
+	fastd_resolve_return_t *ret = (void*)buf;
+	char *hostname = buf + sizeof(fastd_resolve_return_t);
+
+	memset(ret, 0, sizeof(fastd_resolve_return_t));
+
+	ret->constraints = arg->constraints;
+	ret->hostname_len = hostname_len;
+	memcpy(hostname, arg->hostname, hostname_len);
 
 	if (!error) {
 		pr_verbose(arg->ctx, "resolved host `%s' successfully", arg->hostname);
-		memcpy(&ret.addr, res->ai_addr, res->ai_addrlen);
-		fastd_peer_address_simplify(&ret.addr);
+		memcpy(&ret->addr, res->ai_addr, res->ai_addrlen);
+		fastd_peer_address_simplify(&ret->addr);
 	}
 	else {
-		ret.addr.sa.sa_family = AF_UNSPEC;
+		ret->addr.sa.sa_family = AF_UNSPEC;
 	}
 
-	if (write(arg->ctx->resolvewfd, &ret, sizeof(ret)) < 0)
+	if (write(arg->ctx->resolvewfd, buf, sizeof(buf)) < 0)
 		pr_error_errno(arg->ctx, "can't write resolve return");
 
 	freeaddrinfo(res);
+	free(arg->hostname);
 	free(arg);
 
 	return NULL;
@@ -102,14 +109,19 @@ void fastd_resolve_peer(fastd_context_t *ctx, fastd_peer_t *peer) {
 	if (timespec_diff(&ctx->now, &peer->last_resolve) < ctx->conf->min_resolve_interval*1000) {
 		pr_debug(ctx, "not resolving %P as it has been resolved a short time ago", peer);
 
-		fastd_resolve_return_t ret;
-		memset(&ret, 0, sizeof(ret));
+		size_t hostname_len = strlen(peer->config->hostname);
+		char buf[sizeof(fastd_resolve_return_t) + hostname_len];
+
+		fastd_resolve_return_t *ret = (void*)buf;
+		char *hostname = buf + sizeof(fastd_resolve_return_t);
+
+		memset(ret, 0, sizeof(fastd_resolve_return_t));
 
-		ret.hostname = strdup(peer->config->hostname);
-		ret.constraints = peer->config->address;
-		ret.addr = peer->address;
+		ret->constraints = peer->config->address;
+		ret->hostname_len = hostname_len;
+		memcpy(hostname, peer->config->hostname, hostname_len);
 
-		if (write(ctx->resolvewfd, &ret, sizeof(ret)) < 0)
+		if (write(ctx->resolvewfd, buf, sizeof(buf)) < 0)
 			pr_error_errno(ctx, "can't write resolve return");
 
 		return;