Clean up handling of files without a known encapsulation.

Fail with an "unsupported encapsulation" error for MTP2 and SSCOP,
rather than just returning "unknown encapsulation", and fail with that
if the encapsulation isn't filled in as well, although that might be a
deeper problem.

(Not that people should be handing text output files from K12 analyzers
anyway - they should hand us RF5 files and, if we can't handle their
file, file a bug and give us the file so we can further reverse-engineer
the format.)

Change-Id: I6bbd5f81787d69bd3b41eaedf2893d179f11ad6a
Reviewed-on: https://code.wireshark.org/review/5792
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 24 insertions, 16 deletions

diff --git a/wiretap/k12text.l b/wiretap/k12text.l
index 376ea2ce5a..449534b2ae 100644
--- a/wiretap/k12text.l
+++ b/wiretap/k12text.l
@@ -141,8 +141,8 @@ bytes_junk \174[A-F0-9][A-F0-9\040][A-F0-9\040][A-F0-9\040]\174
 byte [a-f0-9][a-f0-9]\174
 end_bytes \015?\012\015?\012
 eth ETHER
- /* mtp2 MTP-L2 ;; XXX: Not supported until it's determined how to fill in the pseudo_header req'd by packet-mtp2 */
- /* sscop SSCOP ;; XXX: Not supported until it's determined how to fill in the pseudo_header req'd by packet-atm  */
+mtp2 MTP-L2
+sscop SSCOP
 sscfnni SSCF
 hdlc HDLC
 
@@ -162,11 +162,11 @@ hdlc HDLC
 <M2N>{comma}  { BEGIN(NS); }
 <NS>{threedigits} { SET_NS(yytext); BEGIN(ENCAP);}
 <ENCAP>{eth} {g_encap = WTAP_ENCAP_ETHERNET; BEGIN(STARTBYTES); }
- /* <ENCAP>{mtp2} {g_encap = WTAP_ENCAP_MTP2; BEGIN(STARTBYTES); }      Not supported as yet */
- /* <ENCAP>{sscop} {g_encap = WTAP_ENCAP_ATM_PDUS; BEGIN(STARTBYTES); } Not supported as yet */
+<ENCAP>{mtp2} {g_encap = WTAP_ENCAP_MTP2; BEGIN(STARTBYTES); }
+<ENCAP>{sscop} {g_encap = WTAP_ENCAP_ATM_PDUS; BEGIN(STARTBYTES); }
 <ENCAP>{sscfnni} {g_encap = WTAP_ENCAP_MTP3; BEGIN(STARTBYTES); }
 <ENCAP>{hdlc} {g_encap = WTAP_ENCAP_CHDLC; BEGIN(STARTBYTES); }
-<ENCAP,STARTBYTES>{start_bytes} { BEGIN(BYTE); }
+<ENCAP,STARTBYTES>{start_bytes} { fprintf(stderr, "OUCH: %s\b", yytext); BEGIN(BYTE); }
 <BYTE>{byte} { ADD_BYTE(yytext); }
 <BYTE>{bytes_junk} ;
 <BYTE>{end_bytes} { FINALIZE_FRAME(); yyterminate(); }
@@ -182,8 +182,8 @@ static void finalize_frame(void) {
 
 /* Fill in pkthdr */
 
-static void
-k12text_set_headers(struct wtap_pkthdr *phdr)
+static gboolean
+k12text_set_headers(struct wtap_pkthdr *phdr, int *err, gchar **err_info)
 {
 	phdr->rec_type = REC_TYPE_PACKET;
 	phdr->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
@@ -204,18 +204,24 @@ k12text_set_headers(struct wtap_pkthdr *phdr)
 	    case WTAP_ENCAP_CHDLC:
 		    /* no pseudo_header to fill in for these types */
 		    break;
-#if 0
 	    case WTAP_ENCAP_MTP2:      /* not (yet) supported		*/
+		    /* XXX: I don't know how to fill in the		*/
+		    /* pseudo_header for these types.			*/
+		    *err = WTAP_ERR_UNSUPPORTED_ENCAP;
+		    *err_info = g_strdup("k12text: MTP2 packets not yet supported");
+		    return FALSE;
 	    case WTAP_ENCAP_ATM_PDUS:  /* not (yet) supported		*/
 		    /* XXX: I don't know how to fill in the		*/
-		    /* pseudo_header for these types. So: The Lexer	*/
-		    /* has recognition for these types commented	*/
-		    /* out ....						*/
-		    break;
-#endif
+		    /* pseudo_header for these types.			*/
+		    *err = WTAP_ERR_UNSUPPORTED_ENCAP;
+		    *err_info = g_strdup("k12text: SSCOP packets not yet supported");
+		    return FALSE;
 	    default:
-		    break;
+		    *err = WTAP_ERR_UNSUPPORTED_ENCAP;
+		    *err_info = g_strdup("k12text: unknown encapsulation type");
+		    return FALSE;
 	}
+	return TRUE;
 }
 
 /* Note: k12text_reset is called each time data is to be processed from	*/
@@ -281,7 +287,8 @@ k12text_read(wtap *wth, int *err, char ** err_info, gint64 *data_offset)
 	*data_offset = k12text->next_frame_offset;       /* file position for beginning of this frame   */
 	k12text->next_frame_offset += file_bytes_read;   /* file position after end of this frame       */
 
-	k12text_set_headers(&wth->phdr);
+	if (!k12text_set_headers(&wth->phdr, err, err_info))
+		return FALSE;
 
 	ws_buffer_assure_space(wth->frame_buffer, wth->phdr.caplen);
 	memcpy(ws_buffer_start_ptr(wth->frame_buffer), bb, wth->phdr.caplen);
@@ -311,7 +318,8 @@ k12text_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *
 		return FALSE;
 	}
 
-	k12text_set_headers(phdr);
+	if (!k12text_set_headers(phdr, err, err_info))
+		return FALSE;
 
 	ws_buffer_assure_space(buf, phdr->caplen);
 	memcpy(ws_buffer_start_ptr(buf), bb, phdr->caplen);