[S] Change in coreboot[main]: util/cbmem: Use commonlib ipchksum() algorithm

[Julius Werner (Code Review)]

Julius Werner has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/80256?usp=email )

Change subject: util/cbmem: Use commonlib ipchksum() algorithm
......................................................................

util/cbmem: Use commonlib ipchksum() algorithm

This patch switches the cbmem utility from its own IP checksum
implementation to the commonlib version (which is good because the old
one had a couple of bugs: doesn't work on odd sizes and may overflow
its carry accumulator with input larger than 64K).

Change-Id: I0bef2c85c37ddd3438b7ac6389e9daa3e4955b31
Signed-off-by: Julius Werner 
---
M util/cbmem/Makefile
M util/cbmem/cbmem.c
2 files changed, 6 insertions(+), 23 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/56/80256/1

diff --git a/util/cbmem/Makefile b/util/cbmem/Makefile
index 9219a08..0c88aeb 100644
--- a/util/cbmem/Makefile
+++ b/util/cbmem/Makefile
@@ -4,6 +4,7 @@
 PROGRAM   = cbmem
 TOP      ?= $(abspath ../..)
 ROOT      = $(TOP)/src
+COMMONLIB = $(ROOT)/commonlib
 CC       ?= $(CROSS_COMPILE)gcc
 INSTALL  ?= /usr/bin/env install
 PREFIX   ?= /usr/local
@@ -13,14 +14,14 @@
 CPPFLAGS += -I . -I $(ROOT)/commonlib/include -I $(ROOT)/commonlib/bsd/include
 CPPFLAGS += -include $(ROOT)/commonlib/bsd/include/commonlib/bsd/compiler.h

-OBJS = $(PROGRAM).o
+OBJS = $(PROGRAM).o $(COMMONLIB)/bsd/ipchksum.o

all: $(PROGRAM)

$(PROGRAM): $(OBJS)

clean:
-	rm -f $(PROGRAM) *.o .dependencies *~ junit.xml
+	rm -f $(PROGRAM) $(OBJS:.c=.o) .dependencies *~ junit.xml

install: $(PROGRAM)
    $(INSTALL) -d $(DESTDIR)$(PREFIX)/sbin/
diff --git a/util/cbmem/cbmem.c b/util/cbmem/cbmem.c
index d33b714..15b6770 100644
--- a/util/cbmem/cbmem.c
+++ b/util/cbmem/cbmem.c
@@ -19,6 +19,7 @@
 #include <assert.h>
 #include <regex.h>
 #include <commonlib/bsd/cbmem_id.h>
+#include <commonlib/bsd/ipchksum.h>
 #include <commonlib/bsd/tpm_log_defs.h>
 #include <commonlib/loglevel.h>
 #include <commonlib/timestamp_serialized.h>
@@ -199,25 +200,6 @@
    return dest;
 }

-/*
- * calculate ip checksum (16 bit quantities) on a passed in buffer. In case
- * the buffer length is odd last byte is excluded from the calculation
- */
-static u16 ipchcksum(const void *addr, unsigned size)
-{
-	const u16 *p = addr;
-	unsigned i, n = size / 2; /* don't expect odd sized blocks */
-	u32 sum = 0;
-
-	for (i = 0; i < n; i++)
-		sum += p[i];
-
-	sum = (sum >> 16) + (sum & 0xffff);
-	sum += (sum >> 16);
-	sum = ~sum & 0xffff;
-	return (u16) sum;
-}
-
 /* Find the first cbmem entry filling in the details. */
 static int find_cbmem_entry(uint32_t id, uint64_t *addr, size_t *size)
 {
@@ -400,7 +382,7 @@
    	lbh = buf + i;
    	if (memcmp(lbh->signature, "LBIO", sizeof(lbh->signature)) ||
    	    !lbh->header_bytes ||
-		    ipchcksum(lbh, sizeof(*lbh))) {
+		    ipchksum(lbh, sizeof(*lbh))) {
    		continue;
    	}

@@ -411,7 +393,7 @@
    		continue;
    	}

-		if (ipchcksum(mapping_virt(&table_mapping), lbh->table_bytes) !=
+		if (ipchksum(mapping_virt(&table_mapping), lbh->table_bytes) !=
    	    lbh->table_checksum) {
    		debug("Signature found, but wrong checksum.\n");
    		unmap_memory(&table_mapping);