diff options
Diffstat (limited to 'arch/ppc/lib/checksum.c')
| -rw-r--r-- | arch/ppc/lib/checksum.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/ppc/lib/checksum.c b/arch/ppc/lib/checksum.c new file mode 100644 index 000000000..0e0a37ea0 --- /dev/null +++ b/arch/ppc/lib/checksum.c @@ -0,0 +1,136 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IP/TCP/UDP checksumming routines + * + * Authors: Jorge Cwik, <jorge@laser.satlink.net> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Tom May, <ftom@netcom.com> + * Lots of code moved from tcp.c and ip.c; see those files + * for more names. + * + * Adapted for PowerPC by Gary Thomas <gdt@mc.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <net/checksum.h> + +/* + * computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit) + * + * returns a 32-bit number suitable for feeding into itself + * or csum_tcpudp_magic + * + * this function must be called with even lengths, except + * for the last fragment, which may be odd + * + * it's best to have buff aligned on a 32-bit boundary + */ +unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) +{ + unsigned long result = ~_csum_partial(buff, len, sum); +#if 0 +printk("Csum partial(%x, %d, %x) = %x\n", buff, len, sum, result); +dump_buf(buff, len); +#endif + return result; +} + +/* + * the same as csum_partial, but copies from src while it + * checksums + * + * here even more important to align src and dst on a 32-bit boundary + */ + +unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum) +{ + /* + * The whole idea is to do the copy and the checksum at + * the same time, but we do it the easy way now. + * + * At least csum on the source, not destination, for cache + * reasons.. + */ + sum = csum_partial(src, len, sum); + memcpy(dst, src, len); + return sum; +} + +extern unsigned short _ip_fast_csum(unsigned char *buf); + +unsigned short +ip_fast_csum(unsigned char *buf, unsigned int len) +{ + unsigned short _val; + _val = _ip_fast_csum(buf); +#if 0 + printk("IP CKSUM(%x, %d) = %x\n", buf, len, _val); + dump_buf(buf, len*4); +#endif + return (_val); +} + +extern unsigned short _ip_compute_csum(unsigned char *buf, int len); + +unsigned short +ip_compute_csum(unsigned char *buf, int len) +{ + unsigned short _val; + _val = _ip_compute_csum(buf, len); +#if 0 + printk("Compute IP CKSUM(%x, %d) = %x\n", buf, len, _val); + dump_buf(buf, len); +#endif + return (_val); +} + +unsigned short +_udp_check(unsigned char *buf, int len, int saddr, int daddr, int hdr); + +unsigned short +udp_check(unsigned char *buf, int len, int saddr, int daddr) +{ + unsigned short _val; + int hdr; + hdr = (len << 16) + IPPROTO_UDP; + _val = _udp_check(buf, len, saddr, daddr, hdr); +#if 0 + printk("UDP CSUM(%x,%d,%x,%x) = %x\n", buf, len, saddr, daddr, _val); + dump_buf(buf, len); +#endif + return (_val); +} + +unsigned short +_tcp_check(unsigned char *buf, int len, int saddr, int daddr, int hdr); + +unsigned short +csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) +{ + unsigned short _val; + _val = _csum_tcpudp_magic(saddr, daddr, sum, (len<<16)+proto); +#if 0 + printk("TCP Magic(%x, %x, %x, %x) = %x\n", saddr, daddr, (len<<16)+proto, sum, _val); +#endif + return (_val); +} + +/* + * Fold a partial checksum without adding pseudo headers + */ + +unsigned short csum_fold(unsigned int sum) +{ + sum = (sum & 0xffff) + (sum >> 16); + sum = (sum & 0xffff) + (sum >> 16); + return ~sum; +} + |