/* $OpenBSD: in_cksum.s,v 1.10 2022/12/08 01:25:44 guenther Exp $ */ /* $NetBSD: in_cksum.S,v 1.2 2003/08/07 16:27:54 agc Exp $ */ /*- * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Charles M. Hannum. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <machine/asm.h> #include "assym.h" /* LINTSTUB: include <sys/types.h> */ /* LINTSTUB: include <machine/param.h> */ /* LINTSTUB: include <sys/mbuf.h> */ /* LINTSTUB: include <netinet/in.h> */ /* * Checksum routine for Internet Protocol family headers. * * in_cksum(m, len) * * Registers used: * %eax = sum * %ebx = m->m_data * %cl = rotation count to unswap * %edx = m->m_len * %ebp = m * %esi = len */ #define SWAP \ roll $8, %eax ; \ xorb $8, %cl #define UNSWAP \ roll %cl, %eax #define MOP \ adcl $0, %eax #define ADVANCE(n) \ leal n(%ebx), %ebx ; \ leal -n(%edx), %edx ; \ #define ADDBYTE \ SWAP ; \ addb (%ebx), %ah #define ADDWORD \ addw (%ebx), %ax #define ADD(n) \ addl n(%ebx), %eax #define ADC(n) \ adcl n(%ebx), %eax #define REDUCE \ movzwl %ax, %edx ; \ shrl $16, %eax ; \ addw %dx, %ax ; \ adcw $0, %ax /* LINTSTUB: Func: int in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len) */ ENTRY(in4_cksum) pushl %ebp pushl %ebx pushl %esi movl 16(%esp), %ebp movzbl 20(%esp), %eax /* sum = nxt */ movl 24(%esp), %edx /* %edx = off */ movl 28(%esp), %esi /* %esi = len */ testl %eax, %eax jz .Lmbuf_loop_0 /* skip if nxt == 0 */ movl M_DATA(%ebp), %ebx addl %esi, %eax /* sum += len */ shll $8, %eax /* sum = htons(sum) */ ADD(IP_SRC) /* sum += ip->ip_src */ ADC(IP_DST) /* sum += ip->ip_dst */ MOP .Lmbuf_loop_0: testl %ebp, %ebp jz .Lout_of_mbufs movl M_DATA(%ebp), %ebx /* %ebx = m_data */ movl M_LEN(%ebp), %ecx /* %ecx = m_len */ movl M_NEXT(%ebp), %ebp subl %ecx, %edx /* %edx = off - m_len */ jnb .Lmbuf_loop_0 addl %edx, %ebx /* %ebx = m_data + off - m_len */ negl %edx /* %edx = m_len - off */ addl %ecx, %ebx /* %ebx = m_data + off */ xorb %cl, %cl /* * The len == 0 case is handled really inefficiently, by going through * the whole short_mbuf path once to get back to mbuf_loop_1 -- but * this case never happens in practice, so it's sufficient that it * doesn't explode. */ jmp .Lin4_entry /* LINTSTUB: Func: int in_cksum(struct mbuf *m, int len) */ ENTRY(in_cksum) pushl %ebp pushl %ebx pushl %esi movl 16(%esp), %ebp movl 20(%esp), %esi xorl %eax, %eax xorb %cl, %cl .Lmbuf_loop_1: testl %esi, %esi jz .Ldone .Lmbuf_loop_2: testl %ebp, %ebp jz .Lout_of_mbufs movl M_DATA(%ebp), %ebx movl M_LEN(%ebp), %edx movl M_NEXT(%ebp), %ebp .Lin4_entry: cmpl %esi, %edx jbe 1f movl %esi, %edx 1: subl %edx, %esi cmpl $32, %edx jb .Lshort_mbuf testb $3, %bl jz .Ldword_aligned testb $1, %bl jz .Lbyte_aligned ADDBYTE ADVANCE(1) MOP testb $2, %bl jz .Lword_aligned .Lbyte_aligned: ADDWORD ADVANCE(2) MOP .Lword_aligned: .Ldword_aligned: testb $4, %bl jnz .Lqword_aligned ADD(0) ADVANCE(4) MOP .Lqword_aligned: testb $8, %bl jz .Loword_aligned ADD(0) ADC(4) ADVANCE(8) MOP .Loword_aligned: subl $128, %edx jb .Lfinished_128 .Lloop_128: ADD(12) ADC(0) ADC(4) ADC(8) ADC(28) ADC(16) ADC(20) ADC(24) ADC(44) ADC(32) ADC(36) ADC(40) ADC(60) ADC(48) ADC(52) ADC(56) ADC(76) ADC(64) ADC(68) ADC(72) ADC(92) ADC(80) ADC(84) ADC(88) ADC(108) ADC(96) ADC(100) ADC(104) ADC(124) ADC(112) ADC(116) ADC(120) leal 128(%ebx), %ebx MOP subl $128, %edx jnb .Lloop_128 .Lfinished_128: subl $32-128, %edx jb .Lfinished_32 .Lloop_32: ADD(12) ADC(0) ADC(4) ADC(8) ADC(28) ADC(16) ADC(20) ADC(24) leal 32(%ebx), %ebx MOP subl $32, %edx jnb .Lloop_32 .Lfinished_32: .Lshort_mbuf: testb $16, %dl jz .Lfinished_16 ADD(12) ADC(0) ADC(4) ADC(8) leal 16(%ebx), %ebx MOP .Lfinished_16: testb $8, %dl jz .Lfinished_8 ADD(0) ADC(4) leal 8(%ebx), %ebx MOP .Lfinished_8: testb $4, %dl jz .Lfinished_4 ADD(0) leal 4(%ebx), %ebx MOP .Lfinished_4: testb $3, %dl jz .Lmbuf_loop_1 testb $2, %dl jz .Lfinished_2 ADDWORD leal 2(%ebx), %ebx MOP testb $1, %dl jz .Lfinished_1 .Lfinished_2: ADDBYTE MOP .Lfinished_1: .Lmbuf_done: testl %esi, %esi jnz .Lmbuf_loop_2 .Ldone: UNSWAP REDUCE notw %ax .Lreturn: popl %esi popl %ebx popl %ebp ret .Lout_of_mbufs: pushl $cksum_ood call printf leal 4(%esp), %esp jmp .Lreturn .section .rodata cksum_ood: .asciz "cksum: out of data\n"
