Current Path : /sys/netinet/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/netinet/sctp_crc32.c |
/*- * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved. * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved. * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * a) Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * b) 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. * * c) Neither the name of Cisco Systems, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/netinet/sctp_crc32.c 237896 2012-07-01 07:59:00Z tuexen $"); #include <netinet/sctp_os.h> #include <netinet/sctp.h> #include <netinet/sctp_crc32.h> #include <netinet/sctp_pcb.h> #if !defined(SCTP_WITH_NO_CSUM) static uint32_t sctp_finalize_crc32c(uint32_t crc32c) { uint32_t result; #if BYTE_ORDER == BIG_ENDIAN uint8_t byte0, byte1, byte2, byte3; #endif /* Complement the result */ result = ~crc32c; #if BYTE_ORDER == BIG_ENDIAN /* * For BIG-ENDIAN.. aka Motorola byte order the result is in * little-endian form. So we must manually swap the bytes. Then we * can call htonl() which does nothing... */ byte0 = result & 0x000000ff; byte1 = (result >> 8) & 0x000000ff; byte2 = (result >> 16) & 0x000000ff; byte3 = (result >> 24) & 0x000000ff; crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3); #else /* * For INTEL platforms the result comes out in network order. No * htonl is required or the swap above. So we optimize out both the * htonl and the manual swap above. */ crc32c = result; #endif return (crc32c); } uint32_t sctp_calculate_cksum(struct mbuf *m, uint32_t offset) { /* * given a mbuf chain with a packetheader offset by 'offset' * pointing at a sctphdr (with csum set to 0) go through the chain * of SCTP_BUF_NEXT()'s and calculate the SCTP checksum. This also * has a side bonus as it will calculate the total length of the * mbuf chain. Note: if offset is greater than the total mbuf * length, checksum=1, pktlen=0 is returned (ie. no real error code) */ uint32_t base = 0xffffffff; struct mbuf *at; at = m; /* find the correct mbuf and offset into mbuf */ while ((at != NULL) && (offset > (uint32_t) SCTP_BUF_LEN(at))) { offset -= SCTP_BUF_LEN(at); /* update remaining offset * left */ at = SCTP_BUF_NEXT(at); } while (at != NULL) { if ((SCTP_BUF_LEN(at) - offset) > 0) { base = calculate_crc32c(base, (unsigned char *)(SCTP_BUF_AT(at, offset)), (unsigned int)(SCTP_BUF_LEN(at) - offset)); } if (offset) { /* we only offset once into the first mbuf */ if (offset < (uint32_t) SCTP_BUF_LEN(at)) offset = 0; else offset -= SCTP_BUF_LEN(at); } at = SCTP_BUF_NEXT(at); } base = sctp_finalize_crc32c(base); return (base); } #endif /* !defined(SCTP_WITH_NO_CSUM) */ void sctp_delayed_cksum(struct mbuf *m, uint32_t offset) { #if defined(SCTP_WITH_NO_CSUM) #ifdef INVARIANTS panic("sctp_delayed_cksum() called when using no SCTP CRC."); #endif #else uint32_t checksum; checksum = sctp_calculate_cksum(m, offset); SCTP_STAT_DECR(sctps_sendhwcrc); SCTP_STAT_INCR(sctps_sendswcrc); offset += offsetof(struct sctphdr, checksum); if (offset + sizeof(uint32_t) > (uint32_t) (m->m_len)) { SCTP_PRINTF("sctp_delayed_cksum(): m->len: %d, off: %d.\n", (uint32_t) m->m_len, offset); /* * XXX this shouldn't happen, but if it does, the correct * behavior may be to insert the checksum in the appropriate * next mbuf in the chain. */ return; } *(uint32_t *) (m->m_data + offset) = checksum; #endif }