laforge has submitted this change. (
https://gerrit.osmocom.org/c/libosmo-netif/+/42463?usp=email )
Change subject: Introduce ip_checksum API
......................................................................
Introduce ip_checksum API
ip_checksum.* files are copied from checksum.* in osmo-ggsn.git
1.14.0 (ebd1bf8adbc8d5bec9e36d70e3a78e8838226e7a).
Change-Id: Ia09645a4715ac133036d7c89297b0fa10cf9aa3b
---
M TODO-RELEASE
M include/osmocom/netif/Makefile.am
A include/osmocom/netif/ip_checksum.h
M src/Makefile.am
A src/ip_checksum.c
5 files changed, 226 insertions(+), 0 deletions(-)
Approvals:
Jenkins Builder: Verified
osmith: Looks good to me, but someone else must approve
fixeria: Looks good to me, approved
laforge: Looks good to me, approved
diff --git a/TODO-RELEASE b/TODO-RELEASE
index 0ed7189..7aebf84 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -7,3 +7,4 @@
# If any interfaces have been added since the last public release: c:r:a + 1.
# If any interfaces have been removed or changed since the last public
release: c:r:0.
#library what description / commit summary line
+netif add osmo_ip_checksum API
diff --git a/include/osmocom/netif/Makefile.am
b/include/osmocom/netif/Makefile.am
index 71f0931..f509221 100644
--- a/include/osmocom/netif/Makefile.am
+++ b/include/osmocom/netif/Makefile.am
@@ -20,6 +20,7 @@
osmonetif_HEADERS = \
amr.h \
datagram.h \
+ ip_checksum.h \
ipa.h \
ipa_unit.h \
jibuf.h \
diff --git a/include/osmocom/netif/ip_checksum.h
b/include/osmocom/netif/ip_checksum.h
new file mode 100644
index 0000000..b5130ee
--- /dev/null
+++ b/include/osmocom/netif/ip_checksum.h
@@ -0,0 +1,11 @@
+#pragma once
+#include <stdint.h>
+#include <netinet/in.h>
+
+uint16_t osmo_ip_checksum_fast_csum(const void *iph, unsigned int ihl);
+uint32_t osmo_ip_checksum_csum_partial(const void *buff, int len, uint32_t
wsum);
+uint16_t osmo_ip_checksum_compute_csum(const void *buff, int len);
+
+uint16_t osmo_ip_checksum_csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ uint32_t len, uint8_t proto, uint32_t
csum);
diff --git a/src/Makefile.am b/src/Makefile.am
index 753bac2..4484e02 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -15,6 +15,7 @@
libosmonetif_la_SOURCES = amr.c \
datagram.c \
+ ip_checksum.c \
ipa.c \
ipa_keepalive.c \
ipa_unit.c \
diff --git a/src/ip_checksum.c b/src/ip_checksum.c
new file mode 100644
index 0000000..1fa6f42
--- /dev/null
+++ b/src/ip_checksum.c
@@ -0,0 +1,212 @@
+/*
+ *
+ * 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, <[email protected]>
+ * Arnt Gulbrandsen, <[email protected]>
+ * Tom May, <[email protected]>
+ * Andreas Schwab, <[email protected]>
+ * Lots of code moved from tcp.c and ip.c; see those files
+ * for more names.
+ *
+ * 03/02/96 Jes Sorensen, Andreas Schwab, Roman Hodek:
+ * Fixed some nasty bugs, causing some horrible crashes.
+ * A: At some points, the sum (%0) was used as
+ * length-counter instead of the length counter
+ * (%1). Thanks to Roman Hodek for pointing this out.
+ * B: GCC seems to mess up if one uses too many
+ * data-registers to hold input values and one tries to
+ * specify d0 and d1 as scratch registers. Letting gcc
+ * choose these registers itself solves the problem.
+ *
+ * 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.
+ */
+
+/* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access
+ kills, so most of the assembly has to go. */
+
+#if defined(__FreeBSD__)
+#define _KERNEL /* needed on FreeBSD 10.x for s6_addr32 */
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/endian.h>
+#endif
+
+#include <arpa/inet.h>
+
+#include <osmocom/netif/ip_checksum.h>
+
+static inline unsigned short from32to16(unsigned int x)
+{
+ /* add up 16-bit and 16-bit for 16+c bit */
+ x = (x & 0xffff) + (x >> 16);
+ /* add up carry.. */
+ x = (x & 0xffff) + (x >> 16);
+ return x;
+}
+
+static unsigned int do_csum(const unsigned char *buff, int len)
+{
+ int odd;
+ unsigned int result = 0;
+
+ if (len <= 0)
+ goto out;
+ odd = 1 & (unsigned long) buff;
+ if (odd) {
+#if BYTE_ORDER == LITTLE_ENDIAN
+ result += (*buff << 8);
+#else
+ result = *buff;
+#endif
+ len--;
+ buff++;
+ }
+ if (len >= 2) {
+ if (2 & (unsigned long) buff) {
+ result += *(unsigned short *) buff;
+ len -= 2;
+ buff += 2;
+ }
+ if (len >= 4) {
+ const unsigned char *end = buff + ((unsigned)len & ~3);
+ unsigned int carry = 0;
+ do {
+ unsigned int w = *(unsigned int *) buff;
+ buff += 4;
+ result += carry;
+ result += w;
+ carry = (w > result);
+ } while (buff < end);
+ result += carry;
+ result = (result & 0xffff) + (result >> 16);
+ }
+ if (len & 2) {
+ result += *(unsigned short *) buff;
+ buff += 2;
+ }
+ }
+ if (len & 1)
+#if BYTE_ORDER == LITTLE_ENDIAN
+ result += *buff;
+#else
+ result += (*buff << 8);
+#endif
+ result = from32to16(result);
+ if (odd)
+ result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+out:
+ return result;
+}
+
+/* fold a partial checksum */
+static uint16_t csum_fold(uint32_t csum)
+{
+ uint32_t sum = (uint32_t)csum;
+ sum = (sum & 0xffff) + (sum >> 16);
+ sum = (sum & 0xffff) + (sum >> 16);
+ return (uint16_t)~sum;
+}
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ */
+uint16_t osmo_ip_checksum_fast_csum(const void *iph, unsigned int ihl)
+{
+ return (uint16_t)~do_csum(iph, ihl*4);
+}
+
+/*
+ * 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
+ */
+uint32_t osmo_ip_checksum_csum_partial(const void *buff, int len, uint32_t
wsum)
+{
+ unsigned int sum = (unsigned int)wsum;
+ unsigned int result = do_csum(buff, len);
+
+ /* add in old sum, and carry.. */
+ result += sum;
+ if (sum > result)
+ result += 1;
+ return (uint32_t)result;
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+uint16_t osmo_ip_checksum_compute_csum(const void *buff, int len)
+{
+ return (uint16_t)~do_csum(buff, len);
+}
+
+uint16_t osmo_ip_checksum_csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ uint32_t len, uint8_t proto, uint32_t
csum)
+{
+ int carry;
+ uint32_t ulen;
+ uint32_t uproto;
+ uint32_t sum = (uint32_t)csum;
+
+ sum += (uint32_t)saddr->s6_addr32[0];
+ carry = (sum < (uint32_t)saddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (uint32_t)saddr->s6_addr32[1];
+ carry = (sum < (uint32_t)saddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (uint32_t)saddr->s6_addr32[2];
+ carry = (sum < (uint32_t)saddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (uint32_t)saddr->s6_addr32[3];
+ carry = (sum < (uint32_t)saddr->s6_addr32[3]);
+ sum += carry;
+
+ sum += (uint32_t)daddr->s6_addr32[0];
+ carry = (sum < (uint32_t)daddr->s6_addr32[0]);
+ sum += carry;
+
+ sum += (uint32_t)daddr->s6_addr32[1];
+ carry = (sum < (uint32_t)daddr->s6_addr32[1]);
+ sum += carry;
+
+ sum += (uint32_t)daddr->s6_addr32[2];
+ carry = (sum < (uint32_t)daddr->s6_addr32[2]);
+ sum += carry;
+
+ sum += (uint32_t)daddr->s6_addr32[3];
+ carry = (sum < (uint32_t)daddr->s6_addr32[3]);
+ sum += carry;
+
+ ulen = (uint32_t)htonl((uint32_t) len);
+ sum += ulen;
+ carry = (sum < ulen);
+ sum += carry;
+
+ uproto = (uint32_t)htonl(proto);
+ sum += uproto;
+ carry = (sum < uproto);
+ sum += carry;
+
+ return csum_fold((uint32_t)sum);
+}
--
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Gerrit-MessageType: merged
Gerrit-Project: libosmo-netif
Gerrit-Branch: master
Gerrit-Change-Id: Ia09645a4715ac133036d7c89297b0fa10cf9aa3b
Gerrit-Change-Number: 42463
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <[email protected]>
Gerrit-Reviewer: laforge <[email protected]>
Gerrit-Reviewer: osmith <[email protected]>
