udhcpd: fix a bug in add_lease where it was reading at [-1]

It is not correct when we read lease file!

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 6 deletions

diff --git a/networking/udhcp/serverpacket.c b/networking/udhcp/serverpacket.c
index c3724e0e2..b48e4159a 100644
--- a/networking/udhcp/serverpacket.c
+++ b/networking/udhcp/serverpacket.c
@@ -130,7 +130,8 @@ int FAST_FUNC send_offer(struct dhcp_packet *oldpacket)
         uint32_t req_nip;
         uint32_t lease_time_sec = server_config.max_lease_sec;
         uint32_t static_lease_ip;
-        uint8_t *req_ip_opt, *p_host_name;
+        uint8_t *req_ip_opt;
+        const char *p_host_name;
         struct option_set *curr;
         struct in_addr addr;
 
@@ -173,8 +174,13 @@ int FAST_FUNC send_offer(struct dhcp_packet *oldpacket)
                         bb_error_msg("no IP addresses to give - OFFER abandoned");
                         return -1;
                 }
-                p_host_name = get_option(oldpacket, DHCP_HOST_NAME);
-                if (!add_lease(packet.chaddr, packet.yiaddr, server_config.offer_time, p_host_name)) {
+                p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME);
+                if (add_lease(packet.chaddr, packet.yiaddr,
+                                server_config.offer_time,
+                                p_host_name,
+                                p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
+                        ) == 0
+                ) {
                         bb_error_msg("lease pool is full - OFFER abandoned");
                         return -1;
                 }
@@ -218,7 +224,7 @@ int FAST_FUNC send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
         struct option_set *curr;
         uint32_t lease_time_sec;
         struct in_addr addr;
-        uint8_t *p_host_name;
+        const char *p_host_name;
 
         init_packet(&packet, oldpacket, DHCPACK);
         packet.yiaddr = yiaddr;
@@ -242,8 +248,12 @@ int FAST_FUNC send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
         if (send_packet(&packet, 0) < 0)
                 return -1;
 
-        p_host_name = get_option(oldpacket, DHCP_HOST_NAME);
-        add_lease(packet.chaddr, packet.yiaddr, lease_time_sec, p_host_name);
+        p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME);
+        add_lease(packet.chaddr, packet.yiaddr,
+                lease_time_sec,
+                p_host_name,
+                p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
+        );
         if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
                 /* rewrite the file with leases at every new acceptance */
                 write_leases();