1 files changed, 53 insertions, 8 deletions

diff --git a/gdhcp/common.c b/gdhcp/common.c
index ac6b1250..6d457ac5 100644..100755
--- a/gdhcp/common.c
+++ b/gdhcp/common.c
@@ -35,6 +35,7 @@
 #include <netpacket/packet.h>
 #include <net/ethernet.h>
 #include <arpa/inet.h>
+#include <fcntl.h>
 
 #include "gdhcp.h"
 #include "common.h"
@@ -58,6 +59,42 @@ static const DHCPOption client_options[] = {
 	{ OPTION_UNKNOWN,		0x00 },
 };
 
+#define URANDOM "/dev/urandom"
+static int random_fd = -1;
+
+int dhcp_get_random(uint64_t *val)
+{
+	int r;
+
+	if (random_fd < 0) {
+		random_fd = open(URANDOM, O_RDONLY);
+		if (random_fd < 0) {
+			r = -errno;
+			*val = random();
+
+			return r;
+		}
+	}
+
+	if (read(random_fd, val, sizeof(uint64_t)) < 0) {
+		r = -errno;
+		*val = random();
+
+		return r;
+	}
+
+	return 0;
+}
+
+void dhcp_cleanup_random(void)
+{
+	if (random_fd < 0)
+		return;
+
+	close(random_fd);
+	random_fd = -1;
+}
+
 GDHCPOptionType dhcp_get_code_type(uint8_t code)
 {
 	int i;
@@ -421,12 +458,14 @@ void dhcp_init_header(struct dhcp_packet *packet, char type)
 void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type)
 {
 	int id;
+	uint64_t rand;
 
 	memset(packet, 0, sizeof(*packet));
 
 	packet->message = type;
 
-	id = random();
+	dhcp_get_random(&rand);
+	id = rand;
 
 	packet->transaction_id[0] = (id >> 16) & 0xff;
 	packet->transaction_id[1] = (id >> 8) & 0xff;
@@ -499,19 +538,14 @@ uint16_t dhcp_checksum(void *addr, int count)
 static const struct in6_addr in6addr_all_dhcp_relay_agents_and_servers_mc =
 	IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT;
 
-/* from netinet/in.h */
-struct in6_pktinfo {
-	struct in6_addr ipi6_addr;  /* src/dst IPv6 address */
-	unsigned int ipi6_ifindex;  /* send/recv interface index */
-};
-
 int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len)
 {
 	struct msghdr m;
 	struct iovec v;
 	struct in6_pktinfo *pktinfo;
 	struct cmsghdr *cmsg;
-	int fd, ret;
+	int fd, ret, opt = 1;
+	struct sockaddr_in6 src;
 	struct sockaddr_in6 dst;
 	void *control_buf;
 	size_t control_buf_len;
@@ -520,6 +554,17 @@ int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len)
 	if (fd < 0)
 		return -errno;
 
+	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+
+	memset(&src, 0, sizeof(src));
+	src.sin6_family = AF_INET6;
+	src.sin6_port = htons(DHCPV6_CLIENT_PORT);
+
+	if (bind(fd, (struct sockaddr *) &src, sizeof(src)) <0) {
+		close(fd);
+		return -errno;
+	}
+
 	memset(&dst, 0, sizeof(dst));
 	dst.sin6_family = AF_INET6;
 	dst.sin6_port = htons(DHCPV6_SERVER_PORT);