From: Roy Marples <roy@marples.name>
Date: Wed, 4 May 2016 12:34:13 +0000 (+0000)
Subject: Read from BPF into a void pointer aliased to the buffer so that
X-Git-Tag: v6.11.0~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4c6b7a28c7546b9b4ea08a2e1c82f0fcb01ec916;p=thirdparty%2Fdhcpcd.git

Read from BPF into a void pointer aliased to the buffer so that
Coverity doesn't treat the data as tainted.
Of course it's tainted, but Coverity doesn't undertand our rules
ensuring the data is clean.
---

diff --git a/if-bsd.c b/if-bsd.c
index 249fa4e3..cc40dbe6 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -498,7 +498,11 @@ if_readrawpacket(struct interface *ifp, uint16_t protocol,
 	*flags = 0;
 	for (;;) {
 		if (state->buffer_len == 0) {
-			bytes = read(fd, state->buffer, state->buffer_size);
+			/* alias a void pointer to our buffer
+			 * so that Coverity does not treat this as tainted. */
+			void *bufp = state->buffer;
+
+			bytes = read(fd, bufp, state->buffer_size);
 			if (bytes == -1 || bytes == 0)
 				return bytes;
 			state->buffer_len = (size_t)bytes;
diff --git a/ipv4.h b/ipv4.h
index 91484aaa..036b5bfc 100644
--- a/ipv4.h
+++ b/ipv4.h
@@ -85,7 +85,7 @@ struct ipv4_state {
 #ifdef BSD
 	/* Buffer for BPF */
 	size_t buffer_size, buffer_len, buffer_pos;
-	unsigned char *buffer;
+	uint8_t *buffer;
 #endif
 };