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/pcap-bpf.c b/pcap-bpf.c
index b7fe0856..17732056 100644
--- a/pcap-bpf.c
+++ b/pcap-bpf.c
@@ -2123,7 +2123,7 @@ pcap_activate_bpf(pcap_t *p)
 					 * the default mode, attempt to
 					 * select the new mode.
 					 */
-					if (new_dlt != v) {
+					if ((u_int)new_dlt != v) {
 						if (ioctl(p->fd, BIOCSDLT,
 						    &new_dlt) != -1) {
 							/*
@@ -2765,7 +2765,7 @@ static int
 find_802_11(struct bpf_dltlist *bdlp)
 {
 	int new_dlt;
-	int i;
+	u_int i;
 
 	/*
 	 * Scan the list of DLT_ values, looking for 802.11 values,