summaryrefslogtreecommitdiffstats
path: root/sbin
diff options
context:
space:
mode:
authorpb <pb@FreeBSD.org>1999-11-15 20:04:53 +0000
committerpb <pb@FreeBSD.org>1999-11-15 20:04:53 +0000
commit4dcdfee42a3ffb9def479161d2e2ab80b5162267 (patch)
treefa6369b19a12b8c2b2309ae0d02395e84bb77599 /sbin
parentac2cbe7bd7b4cd82c4b592681b966a773eb7fcab (diff)
downloadFreeBSD-src-4dcdfee42a3ffb9def479161d2e2ab80b5162267.zip
FreeBSD-src-4dcdfee42a3ffb9def479161d2e2ab80b5162267.tar.gz
Fix aliasing bug causing in_cksum() to fail on odd packet sizes
due to compiler optimization. PR: bin/13292 Suggested by: wollman
Diffstat (limited to 'sbin')
-rw-r--r--sbin/ping/ping.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/sbin/ping/ping.c b/sbin/ping/ping.c
index edbc82a..f96774d 100644
--- a/sbin/ping/ping.c
+++ b/sbin/ping/ping.c
@@ -929,7 +929,10 @@ in_cksum(addr, len)
register int nleft = len;
register u_short *w = addr;
register int sum = 0;
- u_short answer = 0;
+ union {
+ u_int16_t us;
+ u_int8_t uc[2];
+ } answer;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum), we add
@@ -943,15 +946,16 @@ in_cksum(addr, len)
/* mop up an odd byte, if necessary */
if (nleft == 1) {
- *(u_char *)(&answer) = *(u_char *)w ;
- sum += answer;
+ answer.uc[0] = *(u_char *)w;
+ answer.uc[1] = 0;
+ sum += answer.us;
}
/* add back carry outs from top 16 bits to low 16 bits */
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
- answer = ~sum; /* truncate to 16 bits */
- return(answer);
+ answer.us = ~sum; /* truncate to 16 bits */
+ return(answer.us);
}
/*
OpenPOWER on IntegriCloud