Check for, and squelch, signed vs. unsigned comparison errors.

Use -Wsign-compare if the compiler supports it.

If we're comparing an unsigned value with a signed value, and we've
already determined that the signed value is >= 0, just cast it to an
unsigned type.

Use 0xffffffffU instead of -1 as the "unknown"/"unset"/etc. value for
unsigned variables and fields.

Assign the result of str2tok() to an int, not a u_int, as it can return
-1.

Declare some variables and fields unsigned if they don't need to be
signed.  Make sure some arguments passed into "set" functions are
non-negative (and otherwise not invalid).

In the BPF optimizer, cast the "constant" fields of a struct block to an
unsigned type - the actual constant field of a BPF instruction is
unsigned.

Also, cast away one warning from MSVC.

1 files changed, 2 insertions, 2 deletions

diff --git a/sf-pcap.c b/sf-pcap.c
index 55c9a579..061964d1 100644
--- a/sf-pcap.c
+++ b/sf-pcap.c
@@ -876,13 +876,13 @@ pcap_dump_open_append(pcap_t *p, const char *fname)
 			fclose(f);
 			return (NULL);
 		}
-		if (linktype != ph.linktype) {
+		if ((bpf_u_int32)linktype != ph.linktype) {
 			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "%s: different linktype, cannot append to file", fname);
 			fclose(f);
 			return (NULL);
 		}
-		if (p->snapshot != ph.snaplen) {
+		if ((bpf_u_int32)p->snapshot != ph.snaplen) {
 			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 			    "%s: different snaplen, cannot append to file", fname);
 			fclose(f);