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Index: chillispot-1.1.0/src/dhcp.c
===================================================================
--- chillispot-1.1.0.orig/src/dhcp.c 2006-09-24 19:48:25.000000000 +0200
+++ chillispot-1.1.0/src/dhcp.c 2007-09-25 15:35:12.521055038 +0200
@@ -116,6 +116,24 @@
#endif
+/*
+ * BrainSlayer:
+ * wrapper for fixing the big endian bugs within dhcp server code.its surelly not the best.
+ * all dhcp packet fields must be handled in little endian
+ */
+
+static uint16_t swap16(uint16_t word) {
+#if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned char low = word>>8;
+ unsigned char high = word&0xff;
+ return ((uint16_t)(high<<8))|low;
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+ return word;
+#else
+#error "Could not determine the system's endianness"
+#endif
+}
+
/**
* dhcp_ip_check()
* Generates an IPv4 header checksum.
@@ -125,11 +143,11 @@
uint32_t sum = 0;
pack->iph.check = 0;
for (i=0; i<(pack->iph.ihl * 2); i++) {
- sum += ((uint16_t*) &pack->iph)[i];
+ sum += swap16(((uint16_t*) &pack->iph)[i]); /* brainslayer */
}
while (sum>>16)
sum = (sum & 0xFFFF)+(sum >> 16);
- pack->iph.check = ~sum;
+ pack->iph.check = swap16(~sum); /* brainslayer */
return 0;
}
@@ -152,27 +170,28 @@
}
/* Sum UDP header and payload */
+
for (i=0; i<(udp_len/2); i++) {
- sum += ((uint16_t*) &pack->udph)[i];
+ sum += swap16(((uint16_t*) &pack->udph)[i]); /* brainslayer */
}
- /* Sum any uneven payload octet */
+
if (udp_len & 0x01) {
sum += ((uint8_t*) &pack->udph)[udp_len-1];
}
/* Sum both source and destination address */
for (i=0; i<4; i++) {
- sum += ((uint16_t*) &pack->iph.saddr)[i];
+ sum += swap16(((uint16_t*) &pack->iph.saddr)[i]); /* brainslayer */
}
/* Sum both protocol and udp_len (again) */
- sum = sum + pack->udph.len + ((pack->iph.protocol<<8)&0xFF00);
+ sum = sum + swap16(pack->udph.len) + ((pack->iph.protocol<<8)&0xFF00); /* brainslayer */
while (sum>>16)
sum = (sum & 0xFFFF)+(sum >> 16);
- pack->udph.check = ~sum;
+ pack->udph.check = swap16(~sum); /* brainslayer */
return 0;
}
@@ -201,7 +220,7 @@
/* Sum TCP header and payload */
for (i=0; i<(tcp_len/2); i++) {
- sum += ((uint16_t*) pack->payload)[i];
+ sum += swap16(((uint16_t*) pack->payload)[i]); /* brainslayer */
}
/* Sum any uneven payload octet */
@@ -211,16 +230,16 @@
/* Sum both source and destination address */
for (i=0; i<4; i++) {
- sum += ((uint16_t*) &pack->iph.saddr)[i];
+ sum += swap16(((uint16_t*) &pack->iph.saddr)[i]); /* brainslayer */
}
/* Sum both protocol and tcp_len */
- sum = sum + htons(tcp_len) + ((pack->iph.protocol<<8)&0xFF00);
+ sum = sum + swap16(htons(tcp_len)) + ((pack->iph.protocol<<8)&0xFF00); /* brainslayer */
while (sum>>16)
sum = (sum & 0xFFFF)+(sum >> 16);
- tcph->check = ~sum;
+ tcph->check = swap16(~sum); /* brainslayer */
return 0;
}
Index: chillispot-1.1.0/src/dhcp.h
===================================================================
--- chillispot-1.1.0.orig/src/dhcp.h 2006-09-24 19:48:25.000000000 +0200
+++ chillispot-1.1.0/src/dhcp.h 2007-09-25 15:35:12.533055724 +0200
@@ -119,6 +119,8 @@
uint16_t prot;
};
+#include <endian.h>
+
/* Constants for IP packet */
#define DHCP_IP_ALEN 4
#define DHCP_IP_HLEN 20
@@ -127,8 +129,15 @@
#define DHCP_IP_UDP 17 /* UDP Protocol number */
struct dhcp_iphdr_t {
+#if __BYTE_ORDER == __LITTLE_ENDIAN /* nbd fix for swapped version and length field */
uint8_t ihl:4;
uint8_t version:4;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+ uint8_t version:4;
+ uint8_t ihl:4;
+#else
+#error "Could not determine the system's endianness"
+#endif
uint8_t tos;
uint16_t tot_len;
uint16_t id;
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