From dd1d12e8fb4797d94fc2d337b308050a83fb0e0d Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Fri, 4 Nov 2016 16:59:19 +0100
Subject: [PATCH] Store the length of name servers addresses

Always passing sizeof(struct sockaddr_storage) only works, by accident, on Linux.
It fails on macOS and BSD.
---
 src/client.c | 4 ++--
 src/client.h | 7 ++++++-
 src/iodine.c | 7 ++++---
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/client.c b/src/client.c
index 2379618..496dd1d 100644
--- a/src/client.c
+++ b/src/client.c
@@ -352,8 +352,8 @@ send_query(uint8_t *hostname)
 
 	DEBUG(4, "  Sendquery: id %5d name[0] '%c'", q.id, hostname[0]);
 
-	sendto(this.dns_fd, packet, len, 0, (struct sockaddr*) &this.nameserv_addrs[this.current_nameserver],
-			sizeof(struct sockaddr_storage));
+	sendto(this.dns_fd, packet, len, 0, (struct sockaddr*) &this.nameserv_addrs[this.current_nameserver].addr,
+			this.nameserv_addrs[this.current_nameserver].len);
 
 	client_rotate_nameserver();
 
diff --git a/src/client.h b/src/client.h
index 29e5c97..f6750a1 100644
--- a/src/client.h
+++ b/src/client.h
@@ -26,6 +26,11 @@ extern int stats;
 #define PENDING_QUERIES_LENGTH (MAX(this.windowsize_up, this.windowsize_down) * 4)
 #define INSTANCE this
 
+struct nameserv {
+	struct sockaddr_storage addr;
+	int len;
+};
+
 struct client_instance {
 	int max_downstream_frag_size;
 	int autodetect_frag_size;
@@ -37,7 +42,7 @@ struct client_instance {
 	/* DNS nameserver info */
 	char **nameserv_hosts;
 	size_t nameserv_hosts_len;
-	struct sockaddr_storage *nameserv_addrs;
+	struct nameserv *nameserv_addrs;
 	size_t nameserv_addrs_count;
 	int current_nameserver;
 	struct sockaddr_storage raw_serv;
diff --git a/src/iodine.c b/src/iodine.c
index f1ceeae..a2134d1 100644
--- a/src/iodine.c
+++ b/src/iodine.c
@@ -622,7 +622,7 @@ main(int argc, char **argv)
 
 	// Preallocate memory with expected number of hosts
 	this.nameserv_hosts = malloc(sizeof(char *) * this.nameserv_hosts_len);
-	this.nameserv_addrs = malloc(sizeof(struct sockaddr_storage) * this.nameserv_hosts_len);
+	this.nameserv_addrs = malloc(sizeof(struct nameserv) * this.nameserv_hosts_len);
 
 	if (argc == 0) {
 		usage();
@@ -644,7 +644,8 @@ main(int argc, char **argv)
 			errx(1, "Cannot lookup nameserver '%s': %s ",
 					nameserv_host, gai_strerror(nameservaddr_len));
 		}
-		memcpy(&this.nameserv_addrs[n], &nameservaddr, sizeof(struct sockaddr_storage));
+		this.nameserv_addrs[n].len = nameservaddr_len;
+		memcpy(&this.nameserv_addrs[n].addr, &nameservaddr, sizeof(struct sockaddr_storage));
 		this.nameserv_addrs_count ++;
 		nameserv_host = NULL;
 	}
@@ -733,7 +734,7 @@ main(int argc, char **argv)
 
 	fprintf(stderr, "Sending DNS queries for %s to ", this.topdomain);
 	for (int a = 0; a < this.nameserv_addrs_count; a++)
-		fprintf(stderr, "%s%s", format_addr(&this.nameserv_addrs[a], sizeof(struct sockaddr_storage)),
+		fprintf(stderr, "%s%s", format_addr(&this.nameserv_addrs[a].addr, this.nameserv_addrs[a].len),
 				(a != this.nameserv_addrs_count - 1) ?  ", " : "");
 	fprintf(stderr, "\n");