[package] base-files: add an experimental "-c" flag which tries to preserve *all...
[openwrt.git] / package / busybox / patches / 241-udhcpc-oversized_packets.patch
index 9379491..ef9e7f4 100644 (file)
@@ -1,89 +1,99 @@
-Index: busybox-1.7.2/networking/udhcp/packet.c
-===================================================================
---- busybox-1.7.2.orig/networking/udhcp/packet.c       2007-10-30 15:35:00.000000000 -0500
-+++ busybox-1.7.2/networking/udhcp/packet.c    2007-10-30 15:35:01.000000000 -0500
-@@ -121,6 +121,10 @@
+--- a/networking/udhcp/packet.c
++++ b/networking/udhcp/packet.c
+@@ -165,6 +165,11 @@ uint16_t FAST_FUNC udhcp_checksum(void *
        return ~sum;
  }
  
-+int udhcp_get_payload_len(struct dhcpMessage *payload)
++int udhcp_get_payload_len(struct dhcp_packet *dhcp_pkt)
 +{
-+      return sizeof(struct dhcpMessage) - MAX_OPTIONS_LEN + end_option(payload->options) + sizeof(payload->options[0]);
++      return sizeof(struct dhcp_packet) - DHCP_OPTIONS_BUFSIZE + udhcp_end_option(dhcp_pkt->options) + sizeof(dhcp_pkt->options[0]);
 +}
- /* Construct a ip/udp header for a packet, and specify the source and dest hardware address */
- void BUG_sizeof_struct_udp_dhcp_packet_must_be_576(void);
-@@ -132,6 +136,7 @@
-       int result;
-       struct sockaddr_ll dest;
-       struct udp_dhcp_packet packet;
-+      int p_len = udhcp_get_payload_len(payload);
++
+ /* Construct a ip/udp header for a packet, send packet */
+ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
+               uint32_t source_nip, int source_port,
+@@ -173,10 +178,10 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+ {
+       struct sockaddr_ll dest_sll;
+       struct ip_udp_dhcp_packet packet;
+-      unsigned padding;
+       int fd;
+       int result = -1;
+       const char *msg;
++      int p_len = udhcp_get_payload_len(dhcp_pkt);
  
        fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
        if (fd < 0) {
-@@ -141,6 +146,7 @@
+@@ -185,8 +190,8 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+       }
  
-       memset(&dest, 0, sizeof(dest));
-       memset(&packet, 0, sizeof(packet));
-+      memcpy(&(packet.data), payload, p_len);
+       memset(&dest_sll, 0, sizeof(dest_sll));
+-      memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data));
+-      packet.data = *dhcp_pkt; /* struct copy */
++      memset(&packet, 0, sizeof(packet));
++      memcpy(&(packet.data), dhcp_pkt, p_len);
+       dest_sll.sll_family = AF_PACKET;
+       dest_sll.sll_protocol = htons(ETH_P_IP);
+@@ -199,36 +204,24 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+               goto ret_close;
+       }
  
-       dest.sll_family = AF_PACKET;
-       dest.sll_protocol = htons(ETH_P_IP);
-@@ -158,12 +164,13 @@
-       packet.ip.daddr = dest_ip;
+-      /* We were sending full-sized DHCP packets (zero padded),
+-       * but some badly configured servers were seen dropping them.
+-       * Apparently they drop all DHCP packets >576 *ethernet* octets big,
+-       * whereas they may only drop packets >576 *IP* octets big
+-       * (which for typical Ethernet II means 590 octets: 6+6+2 + 576).
+-       *
+-       * In order to work with those buggy servers,
+-       * we truncate packets after end option byte.
+-       */
+-      padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(packet.data.options);
+-
+       packet.ip.protocol = IPPROTO_UDP;
+       packet.ip.saddr = source_nip;
+       packet.ip.daddr = dest_nip;
        packet.udp.source = htons(source_port);
        packet.udp.dest = htons(dest_port);
--      packet.udp.len = htons(sizeof(packet.udp) + sizeof(struct dhcpMessage)); /* cheat on the psuedo-header */
+-      /* size, excluding IP header: */
+-      packet.udp.len = htons(UPD_DHCP_SIZE - padding);
+-      /* for UDP checksumming, ip.len is set to UDP packet len */
 +      p_len += sizeof(packet.udp);
 +      packet.udp.len = htons(p_len);
        packet.ip.tot_len = packet.udp.len;
--      memcpy(&(packet.data), payload, sizeof(struct dhcpMessage));
--      packet.udp.check = udhcp_checksum(&packet, sizeof(struct udp_dhcp_packet));
+-      packet.udp.check = udhcp_checksum(&packet, IP_UPD_DHCP_SIZE - padding);
+-      /* but for sending, it is set to IP packet len */
+-      packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE - padding);
 +      p_len += sizeof(packet.ip);
 +      packet.udp.check = udhcp_checksum(&packet, p_len);
--      packet.ip.tot_len = htons(sizeof(struct udp_dhcp_packet));
 +      packet.ip.tot_len = htons(p_len);
        packet.ip.ihl = sizeof(packet.ip) >> 2;
        packet.ip.version = IPVERSION;
        packet.ip.ttl = IPDEFTTL;
-@@ -172,7 +179,7 @@
-       if (sizeof(struct udp_dhcp_packet) != 576)
-               BUG_sizeof_struct_udp_dhcp_packet_must_be_576();
+       packet.ip.check = udhcp_checksum(&packet.ip, sizeof(packet.ip));
  
--      result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0,
-+      result = sendto(fd, &packet, p_len, 0,
-                       (struct sockaddr *) &dest, sizeof(dest));
-       if (result <= 0) {
-               bb_perror_msg("sendto");
-@@ -216,7 +223,7 @@
-               return -1;
+       udhcp_dump_packet(dhcp_pkt);
+-      result = sendto(fd, &packet, IP_UPD_DHCP_SIZE - padding, /*flags:*/ 0,
++      result = sendto(fd, &packet, p_len, /*flags:*/ 0,
+                       (struct sockaddr *) &dest_sll, sizeof(dest_sll));
+       msg = "sendto";
+  ret_close:
+@@ -246,7 +239,6 @@ int FAST_FUNC udhcp_send_kernel_packet(s
+               uint32_t dest_nip, int dest_port)
+ {
+       struct sockaddr_in client;
+-      unsigned padding;
+       int fd;
+       int result = -1;
+       const char *msg;
+@@ -277,9 +269,7 @@ int FAST_FUNC udhcp_send_kernel_packet(s
        }
  
--      result = write(fd, payload, sizeof(struct dhcpMessage));
-+      result = write(fd, payload, udhcp_get_payload_len(payload));
+       udhcp_dump_packet(dhcp_pkt);
+-
+-      padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(dhcp_pkt->options);
+-      result = safe_write(fd, dhcp_pkt, DHCP_SIZE - padding);
++      result = safe_write(fd, dhcp_pkt, udhcp_get_payload_len(dhcp_pkt));
+       msg = "write";
+  ret_close:
        close(fd);
-       return result;
- }
-Index: busybox-1.7.2/networking/udhcp/common.h
-===================================================================
---- busybox-1.7.2.orig/networking/udhcp/common.h       2007-10-30 15:35:00.000000000 -0500
-+++ busybox-1.7.2/networking/udhcp/common.h    2007-10-30 15:35:01.000000000 -0500
-@@ -21,6 +21,8 @@
- #include <netinet/udp.h>
- #include <netinet/ip.h>
-+#define MAX_OPTIONS_LEN  308
-+
- struct dhcpMessage {
-       uint8_t op;
-       uint8_t htype;
-@@ -37,7 +39,7 @@
-       uint8_t sname[64];
-       uint8_t file[128];
-       uint32_t cookie;
--      uint8_t options[308]; /* 312 - cookie */
-+      uint8_t options[MAX_OPTIONS_LEN]; /* 312 - cookie */
- };
- struct udp_dhcp_packet {
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