Makefile: change version to 1.10.0.svn

[oweals/busybox.git] / networking / udhcp / clientpacket.c

diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c
index 03473109f9436e1296b11784b87d76800be64c95..b8190ba43ef694dd4a19d98f31c9d9cfd4faf357 100644 (file)
--- a/networking/udhcp/clientpacket.c
+++ b/networking/udhcp/clientpacket.c
@@ -167,39 +167,40 @@ int send_release(uint32_t server, uint32_t ciaddr)
 }
 
 
-/* return -1 on errors that are fatal for the socket, -2 for those that aren't */
+/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
 int get_raw_packet(struct dhcpMessage *payload, int fd)
 {
        int bytes;
        struct udp_dhcp_packet packet;
        uint16_t check;
 
-       memset(&packet, 0, sizeof(struct udp_dhcp_packet));
-       bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet));
+       memset(&packet, 0, sizeof(packet));
+       bytes = safe_read(fd, &packet, sizeof(packet));
        if (bytes < 0) {
                DEBUG("Cannot read on raw listening socket - ignoring");
                sleep(1); /* possible down interface, looping condition */
-               return -1;
+               return bytes; /* returns -1 */
        }
 
-       if (bytes < (int) (sizeof(struct iphdr) + sizeof(struct udphdr))) {
-               DEBUG("Message too short, ignoring");
+       if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
+               DEBUG("Packet is too short, ignoring");
                return -2;
        }
 
        if (bytes < ntohs(packet.ip.tot_len)) {
-               DEBUG("Truncated packet");
+               /* packet is bigger than sizeof(packet), we did partial read */
+               DEBUG("Oversized packet, ignoring");
                return -2;
        }
 
        /* ignore any extra garbage bytes */
        bytes = ntohs(packet.ip.tot_len);
 
-       /* Make sure its the right packet for us, and that it passes sanity checks */
+       /* make sure its the right packet for us, and that it passes sanity checks */
        if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
         || packet.ip.ihl != (sizeof(packet.ip) >> 2)
         || packet.udp.dest != htons(CLIENT_PORT)
-        || bytes > (int) sizeof(struct udp_dhcp_packet)
+       /* || bytes > (int) sizeof(packet) - can't happen */
         || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
        ) {
                DEBUG("Unrelated/bogus packet");
@@ -211,12 +212,12 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
        packet.ip.check = 0;
        if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
                DEBUG("Bad IP header checksum, ignoring");
-               return -1;
+               return -2;
        }
 
        /* verify UDP checksum. IP header has to be modified for this */
        memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
-       /* fields which are not memset: protocol, check, saddr, daddr */
+       /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
        packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
        check = packet.udp.check;
        packet.udp.check = 0;
@@ -228,7 +229,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
        memcpy(payload, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
 
        if (payload->cookie != htonl(DHCP_MAGIC)) {
-               bb_error_msg("received bogus message (bad magic) - ignoring");
+               bb_error_msg("received bogus message (bad magic), ignoring");
                return -2;
        }
        DEBUG("Got valid DHCP packet");