| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _ASM_IA64_CHECKSUM_H |
| 2 | #define _ASM_IA64_CHECKSUM_H |
| 3 | |
| 4 | /* |
| 5 | * Modified 1998, 1999 |
| 6 | * David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * This is a version of ip_compute_csum() optimized for IP headers, |
| 11 | * which always checksum on 4 octet boundaries. |
| 12 | */ |
| 13 | extern unsigned short ip_fast_csum (unsigned char * iph, unsigned int ihl); |
| 14 | |
| 15 | /* |
| 16 | * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit |
| 17 | * checksum, already complemented |
| 18 | */ |
| 19 | extern unsigned short int csum_tcpudp_magic (unsigned long saddr, |
| 20 | unsigned long daddr, |
| 21 | unsigned short len, |
| 22 | unsigned short proto, |
| 23 | unsigned int sum); |
| 24 | |
| 25 | extern unsigned int csum_tcpudp_nofold (unsigned long saddr, |
| 26 | unsigned long daddr, |
| 27 | unsigned short len, |
| 28 | unsigned short proto, |
| 29 | unsigned int sum); |
| 30 | |
| 31 | /* |
| 32 | * Computes the checksum of a memory block at buff, length len, |
| 33 | * and adds in "sum" (32-bit) |
| 34 | * |
| 35 | * returns a 32-bit number suitable for feeding into itself |
| 36 | * or csum_tcpudp_magic |
| 37 | * |
| 38 | * this function must be called with even lengths, except |
| 39 | * for the last fragment, which may be odd |
| 40 | * |
| 41 | * it's best to have buff aligned on a 32-bit boundary |
| 42 | */ |
| 43 | extern unsigned int csum_partial (const unsigned char * buff, int len, |
| 44 | unsigned int sum); |
| 45 | |
| 46 | /* |
| 47 | * Same as csum_partial, but copies from src while it checksums. |
| 48 | * |
| 49 | * Here it is even more important to align src and dst on a 32-bit (or |
| 50 | * even better 64-bit) boundary. |
| 51 | */ |
| 52 | extern unsigned int csum_partial_copy_from_user (const char *src, char *dst, |
| 53 | int len, unsigned int sum, |
| 54 | int *errp); |
| 55 | |
| 56 | extern unsigned int csum_partial_copy_nocheck (const char *src, char *dst, |
| 57 | int len, unsigned int sum); |
| 58 | |
| 59 | /* |
| 60 | * This routine is used for miscellaneous IP-like checksums, mainly in |
| 61 | * icmp.c |
| 62 | */ |
| 63 | extern unsigned short ip_compute_csum (unsigned char *buff, int len); |
| 64 | |
| 65 | /* |
| 66 | * Fold a partial checksum without adding pseudo headers. |
| 67 | */ |
| 68 | static inline unsigned short |
| 69 | csum_fold (unsigned int sum) |
| 70 | { |
| 71 | sum = (sum & 0xffff) + (sum >> 16); |
| 72 | sum = (sum & 0xffff) + (sum >> 16); |
| 73 | return ~sum; |
| 74 | } |
| 75 | |
| 76 | #endif /* _ASM_IA64_CHECKSUM_H */ |