X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..ccc36f2f2d89f9115c479db4439aa5c88de5b44a:/bsd/netinet/in_cksum.c?ds=sidebyside diff --git a/bsd/netinet/in_cksum.c b/bsd/netinet/in_cksum.c index 4262277c9..9d349d7b5 100644 --- a/bsd/netinet/in_cksum.c +++ b/bsd/netinet/in_cksum.c @@ -67,10 +67,64 @@ * code and should be modified for each CPU to be as fast as possible. */ +union s_util { + char c[2]; + u_short s; +}; +union l_util { + u_int16_t s[2]; + u_int32_t l; +}; +union q_util { + u_int16_t s[4]; + u_int32_t l[2]; + u_int64_t q; +}; + +#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) + +#define REDUCE32 \ + { \ + q_util.q = sum; \ + sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ + } +#define REDUCE16 \ + { \ + q_util.q = sum; \ + l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ + sum = l_util.s[0] + l_util.s[1]; \ + ADDCARRY(sum); \ + } + +#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} + + #if defined(ppc) +__inline unsigned short +in_addword(u_short a, u_short b) +{ + union l_util l_util; + u_int32_t sum = a + b; + REDUCE; + return (sum); +} + +__inline unsigned short +in_pseudo(u_int a, u_int b, u_int c) +{ + u_int64_t sum; + union q_util q_util; + union l_util l_util; + + sum = (u_int64_t) a + b + c; + REDUCE16; + return (sum); + +} + int in_cksum(m, len) register struct mbuf *m; @@ -108,12 +162,71 @@ in_cksum(m, len) return (~sum & 0xffff); } +u_short +in_cksum_skip(m, len, skip) + register struct mbuf *m; + register int len; + register int skip; +{ + register u_short *w; + register int sum = 0; + register int mlen = 0; + int starting_on_odd = 0; + + len -= skip; + for (; skip && m; m = m->m_next) { + if (m->m_len > skip) { + mlen = m->m_len - skip; + w = (u_short *)(m->m_data+skip); + goto skip_start; + } else { + skip -= m->m_len; + } + } + for (;m && len; m = m->m_next) { + if (m->m_len == 0) + continue; + mlen = m->m_len; + w = mtod(m, u_short *); + +skip_start: + if (len < mlen) + mlen = len; + sum = xsum_assym(w, mlen, sum, starting_on_odd); + len -= mlen; + if (mlen & 0x1) + { + if (starting_on_odd) + starting_on_odd = 0; + else + starting_on_odd = 1; + } + } + + return (~sum & 0xffff); +} #else +u_short +in_addword(u_short a, u_short b) +{ + union l_util l_util; + u_int32_t sum = a + b; + REDUCE(sum); + return (sum); +} -#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) -#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} +u_short +in_pseudo(u_int a, u_int b, u_int c) +{ + u_int64_t sum; + union q_util q_util; + union l_util l_util; + sum = (u_int64_t) a + b + c; + REDUCE16; + return (sum); +} int @@ -125,15 +238,8 @@ in_cksum(m, len) register int sum = 0; register int mlen = 0; int byte_swapped = 0; - - union { - char c[2]; - u_short s; - } s_util; - union { - u_short s[2]; - long l; - } l_util; + union s_util s_util; + union l_util l_util; KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0); @@ -221,4 +327,117 @@ in_cksum(m, len) return (~sum & 0xffff); } +int +in_cksum_skip(m, len, skip) + register struct mbuf *m; + register u_short len; + register u_short skip; +{ + register u_short *w; + register int sum = 0; + register int mlen = 0; + int byte_swapped = 0; + union s_util s_util; + union l_util l_util; + + KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0); + + len -= skip; + for (; skip && m; m = m->m_next) { + if (m->m_len > skip) { + mlen = m->m_len - skip; + w = (u_short *)(m->m_data+skip); + goto skip_start; + } else { + skip -= m->m_len; + } + } + for (;m && len; m = m->m_next) { + if (m->m_len == 0) + continue; + w = mtod(m, u_short *); + + if (mlen == -1) { + /* + * The first byte of this mbuf is the continuation + * of a word spanning between this mbuf and the + * last mbuf. + * + * s_util.c[0] is already saved when scanning previous + * mbuf. + */ + s_util.c[1] = *(char *)w; + sum += s_util.s; + w = (u_short *)((char *)w + 1); + mlen = m->m_len - 1; + len--; + } else { + mlen = m->m_len; + } +skip_start: + if (len < mlen) + mlen = len; + + len -= mlen; + /* + * Force to even boundary. + */ + if ((1 & (int) w) && (mlen > 0)) { + REDUCE; + sum <<= 8; + s_util.c[0] = *(u_char *)w; + w = (u_short *)((char *)w + 1); + mlen--; + byte_swapped = 1; + } + /* + * Unroll the loop to make overhead from + * branches &c small. + */ + while ((mlen -= 32) >= 0) { + sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; + sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7]; + sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11]; + sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15]; + w += 16; + } + mlen += 32; + while ((mlen -= 8) >= 0) { + sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; + w += 4; + } + mlen += 8; + if (mlen == 0 && byte_swapped == 0) + continue; + REDUCE; + while ((mlen -= 2) >= 0) { + sum += *w++; + } + if (byte_swapped) { + REDUCE; + sum <<= 8; + byte_swapped = 0; + if (mlen == -1) { + s_util.c[1] = *(char *)w; + sum += s_util.s; + mlen = 0; + } else + mlen = -1; + } else if (mlen == -1) + s_util.c[0] = *(char *)w; + } + if (len) + printf("cksum: out of data\n"); + if (mlen == -1) { + /* The last mbuf has odd # of bytes. Follow the + standard (the odd byte may be shifted left by 8 bits + or not as determined by endian-ness of the machine) */ + s_util.c[1] = 0; + sum += s_util.s; + } + REDUCE; + KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0); + return (~sum & 0xffff); +} + #endif