diff options
Diffstat (limited to 'src/checksum.c')
| -rw-r--r-- | src/checksum.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/src/checksum.c b/src/checksum.c index 300237d..5c6415a 100644 --- a/src/checksum.c +++ b/src/checksum.c @@ -31,21 +31,24 @@ /* Based on code from the Linux kernel. */ +#include <assert.h> +#include <endian.h> #include <stdint.h> +#include "checksum.h" /* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access kills, so most of the assembly has to go. */ -static inline unsigned short from32to16(unsigned int x) +static inline uint16_t from32to16(uint32_t x) { /* add up 16-bit and 16-bit for 16+c bit */ x = (x & 0xffff) + (x >> 16); /* add up carry.. */ x = (x & 0xffff) + (x >> 16); - return x; + return (uint16_t)x; } -static unsigned int do_csum(const unsigned char *buff, int len) +static uint16_t do_csum(const unsigned char *buff, int len) { int odd; unsigned int result = 0; @@ -55,24 +58,26 @@ static unsigned int do_csum(const unsigned char *buff, int len) odd = 1 & (unsigned long) buff; if (odd) { #if __BYTE_ORDER == __LITTLE_ENDIAN - result += (*buff << 8); + result += ((unsigned int)(*buff) << 8); #else result = *buff; #endif len--; buff++; } + assert(!((unsigned long)buff & 1)); if (len >= 2) { - if (2 & (unsigned long) buff) { - result += *(unsigned short *) buff; + if (2 & (const unsigned long) buff) { + result += *(const unsigned short *) buff; len -= 2; buff += 2; } + assert(!((unsigned long)buff & 2)); if (len >= 4) { - const unsigned char *end = buff + ((unsigned)len & ~3); + const unsigned char *end = buff + ((unsigned)len & ~3u); unsigned int carry = 0; do { - unsigned int w = *(unsigned int *) buff; + unsigned int w = *(const unsigned int *) buff; buff += 4; result += carry; result += w; @@ -82,7 +87,7 @@ static unsigned int do_csum(const unsigned char *buff, int len) result = (result & 0xffff) + (result >> 16); } if (len & 2) { - result += *(unsigned short *) buff; + result += *(const unsigned short *) buff; buff += 2; } } @@ -96,7 +101,7 @@ static unsigned int do_csum(const unsigned char *buff, int len) if (odd) result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); out: - return result; + return (uint16_t)result; } /* |