Add versions sanity checks for pcap and pcap-ng savefiles

pcap:
    Currently only versions 2.[0-4] are supported with the exception
    of 543.0 for DG/UX tcpdump.
    Versions < 2.x were already rejected as "archaic".

pcap-ng:
    Currently only SHB version 1.0 is supported.
    (reference: https://github.com/pcapng/pcapng)

2 files changed, 22 insertions, 4 deletions

diff --git a/sf-pcap-ng.c b/sf-pcap-ng.c
index 15962a10..9bee799a 100644
--- a/sf-pcap-ng.c
+++ b/sf-pcap-ng.c
@@ -121,6 +121,7 @@ struct section_header_block {
  * that means that this code can't read the file.
  */
 #define PCAP_NG_VERSION_MAJOR	1
+#define PCAP_NG_VERSION_MINOR	0
 
 /*
  * Interface Description Block.
@@ -891,10 +892,12 @@ pcap_ng_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf,
 		 * XXX - we don't care about the section length.
 		 */
 	}
-	if (shbp->major_version != PCAP_NG_VERSION_MAJOR) {
+	/* currently only SHB version 1.0 is supported */
+	if (! (shbp->major_version == PCAP_NG_VERSION_MAJOR &&
+	       shbp->minor_version == PCAP_NG_VERSION_MINOR)) {
 		snprintf(errbuf, PCAP_ERRBUF_SIZE,
-		    "unknown pcap-ng savefile major version number %u",
-		    shbp->major_version);
+		    "unsupported pcap-ng savefile version %u.%u",
+		    shbp->major_version, shbp->minor_version);
 		goto fail;
 	}
 	p->version_major = shbp->major_version;
diff --git a/sf-pcap.c b/sf-pcap.c
index 593a30db..c950f778 100644
--- a/sf-pcap.c
+++ b/sf-pcap.c
@@ -149,7 +149,7 @@ struct pcap_sf {
  */
 pcap_t *
 pcap_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf,
-    int *err)
+		  int *err)
 {
 	struct pcap_file_header hdr;
 	size_t amt_read;
@@ -218,6 +218,21 @@ pcap_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf,
 	}
 
 	/*
+	 * currently only versions 2.[0-4] are supported with
+	 * the exception of 543.0 for DG/UX tcpdump.
+	 */
+	if (! ((hdr.version_major == PCAP_VERSION_MAJOR &&
+		hdr.version_minor <= PCAP_VERSION_MINOR) ||
+	       (hdr.version_major == 543 &&
+		hdr.version_minor == 0))) {
+		snprintf(errbuf, PCAP_ERRBUF_SIZE,
+			 "unsupported pcap savefile version %u.%u",
+			 hdr.version_major, hdr.version_minor);
+		*err = 1;
+		return NULL;
+	}
+
+	/*
 	 * OK, this is a good pcap file.
 	 * Allocate a pcap_t for it.
 	 */