Make the Flex scanners and YACC parser in libraries reentrant.

master-branch libpcap now generates a reentrant Flex scanner and
Bison/Berkeley YACC parser for capture filter expressions, so it
requires versions of Flex and Bison/Berkeley YACC that support that.

We might as well do the same.  For libwiretap, it means we could
actually have multiple K12 text or Ascend/Lucent text files open at the
same time.  For libwireshark, it might not be as useful, as we only read
configuration files at startup (which should only happen once, in one
thread) or on demand (in which case, if we ever support multiple threads
running libwireshark, we'd need a mutex to ensure that only one file
reads it), but it's still the right thing to do.

We also require a version of Flex that can write out a header file, so
we change the runlex script to generate the header file ourselves. This
means we require a version of Flex new enough to support --header-file.

Clean up some other stuff encountered in the process.

Change-Id: Id23078c6acea549a52fc687779bb55d715b55c16
Reviewed-on: https://code.wireshark.org/review/14719
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 159 insertions, 236 deletions

diff --git a/wiretap/ascend.y b/wiretap/ascend.y
index dc30a9e78f..31f9cbc88e 100644
--- a/wiretap/ascend.y
+++ b/wiretap/ascend.y
@@ -1,3 +1,28 @@
+/*
+ * We want a reentrant parser.
+ */
+%pure-parser
+
+/*
+ * We also want a reentrant scanner, so we have to pass the
+ * handle for the reentrant scanner to the parser, and the
+ * parser has to pass it to the lexical analyzer.
+ *
+ * We use void * rather than yyscan_t because, at least with some
+ * versions of Flex and Bison, if you use yyscan_t in %parse-param and
+ * %lex-param, you have to include the ascend_lex_scanner.h before
+ * ascend.h to get yyscan_t declared, and you have to include ascend.h
+ * before ascend_lex_scanner.h to get YYSTYPE declared.  Using void *
+ * breaks the cycle; the Flex documentation says yyscan_t is just a void *.
+ */
+%parse-param {void *yyscanner}
+%lex-param {void *yyscanner}
+
+/*
+ * And we need to pass the parser state to the scanner.
+ */
+%parse-param {ascend_state_t *parser_state}
+
 %{
 /* ascend.y
  *
@@ -135,22 +160,13 @@ XMIT-Max7:20: (task "_brouterControlTask" at 0xb094ac20, time: 1481.51) 20 octet
 #include <wsutil/buffer.h>
 #include "ascendtext.h"
 #include "ascend-int.h"
+#include "ascend.h"
+#include "ascend_scanner_lex.h"
 #include "file_wrappers.h"
 
 #define NO_USER "<none>"
 
-int yyparse(FILE_T fh);
-void yyerror(FILE_T fh _U_, const char *);
-
-const gchar *ascend_parse_error;
-
-static unsigned int bcur;
-static guint32 start_time, usecs, caplen, wirelen;
-static time_t secs;
-struct ascend_phdr *pseudo_header;
-static guint8 *pkt_data;
-static gint64 first_hexbyte;
-
+extern void yyerror (void *yyscanner, ascend_state_t *state, FILE_T fh _U_, const char *s);
 %}
 
 %union {
@@ -208,19 +224,19 @@ PRI-XMIT-0/2 (task "l1Task" at 0x80152b20, time: 283529.65) 10 octets @
 
 */
 deferred_isdn_hdr: isdn_prefix decnum SLASH_SUFFIX KEYWORD string KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen += $11;
-  caplen += $11;
-  secs = $9;
-  usecs = $10;
-  if (pseudo_header != NULL) {
-    pseudo_header->type = $1;
-    pseudo_header->sess = $2;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $7;
+  parser_state->wirelen += $11;
+  parser_state->caplen += $11;
+  parser_state->secs = $9;
+  parser_state->usecs = $10;
+  if (parser_state->pseudo_header != NULL) {
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $2;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $7;
   }
   /* because we have two data groups */
-  first_hexbyte = 0;
+  parser_state->first_hexbyte = 0;
 }
 ;
 
@@ -230,18 +246,18 @@ PRI-XMIT-19:  (task "l1Task" at 0x10216840, time: 274758.67) 4 octets @ 0x1027c1
 PRI-RCV-27:  (task "idle task" at 0x10123570, time: 560194.01) 4 octets @ 0x1027fb00
 */
 isdn_hdr: isdn_prefix decnum KEYWORD string KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $10;
-  caplen = $10;
-  secs = $8;
-  usecs = $9;
-  if (pseudo_header != NULL) {
-    pseudo_header->type = $1;
-    pseudo_header->sess = $2;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $6;
+  parser_state->wirelen = $10;
+  parser_state->caplen = $10;
+  parser_state->secs = $8;
+  parser_state->usecs = $9;
+  if (parser_state->pseudo_header != NULL) {
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $2;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $6;
   }
-  first_hexbyte = 0;
+  parser_state->first_hexbyte = 0;
 }
 ;
 
@@ -251,15 +267,15 @@ ETHER3ND XMIT: (task "_sarTask" at 0x802c6eb0, time: 259848.11) 414 octets @ 0xa
 */
 ether_hdr: ether_prefix string KEYWORD string KEYWORD hexnum KEYWORD decnum decnum
  decnum KEYWORD HEXNUM {
-  wirelen = $10;
-  caplen = $10;
-  secs = $8;
-  usecs = $9;
-  if (pseudo_header != NULL) {
-    pseudo_header->type = $1;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $6;
+  parser_state->wirelen = $10;
+  parser_state->caplen = $10;
+  parser_state->secs = $8;
+  parser_state->usecs = $9;
+  if (parser_state->pseudo_header != NULL) {
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $6;
   }
 }
 ;
@@ -267,17 +283,17 @@ ether_hdr: ether_prefix string KEYWORD string KEYWORD hexnum KEYWORD decnum decn
 /* RECV-iguana:241:(task: B02614C0, time: 1975432.85) 49 octets @ 8003BD94 */
 /*            1        2      3      4       5      6       7      8      9      10     11 */
 wds_hdr: wds_prefix string decnum KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $9;
-  caplen = $9;
-  secs = $7;
-  usecs = $8;
-  if (pseudo_header != NULL) {
-    /* pseudo_header->user is set in ascend_scanner.l */
-    pseudo_header->type = $1;
-    pseudo_header->sess = $3;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $5;
+  parser_state->wirelen = $9;
+  parser_state->caplen = $9;
+  parser_state->secs = $7;
+  parser_state->usecs = $8;
+  if (parser_state->pseudo_header != NULL) {
+    /* parser_state->pseudo_header->user is set in ascend_scanner.l */
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $3;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $5;
   }
 }
 ;
@@ -285,17 +301,17 @@ wds_hdr: wds_prefix string decnum KEYWORD hexnum KEYWORD decnum decnum decnum KE
 /* RECV-Max7:20: (task "_brouterControlTask" at 0xb094ac20, time: 1481.50) 20 octets @ 0x8000d198 */
 /*                1       2       3     4       5       6      7       8      9      10     11     12      13 */
 wds8_hdr: wds_prefix string decnum KEYWORD string KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $11;
-  caplen = $11;
-  secs = $9;
-  usecs = $10;
-  if (pseudo_header != NULL) {
-    /* pseudo_header->user is set in ascend_scanner.l */
-    pseudo_header->type = $1;
-    pseudo_header->sess = $3;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $7;
+  parser_state->wirelen = $11;
+  parser_state->caplen = $11;
+  parser_state->secs = $9;
+  parser_state->usecs = $10;
+  if (parser_state->pseudo_header != NULL) {
+    /* parser_state->pseudo_header->user is set in ascend_scanner.l */
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $3;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $7;
   }
 }
 ;
@@ -303,17 +319,17 @@ wds8_hdr: wds_prefix string decnum KEYWORD string KEYWORD hexnum KEYWORD decnum
 /* RECV-187:(task: B050B480, time: 18042248.03) 100 octets @ 800012C0 */
 /*            1        2       3      4       5       6      7      8      9      10    */
 wdp7_hdr: wds_prefix decnum KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $8;
-  caplen = $8;
-  secs = $6;
-  usecs = $7;
-  if (pseudo_header != NULL) {
-    /* pseudo_header->user is set in ascend_scanner.l */
-    pseudo_header->type = $1;
-    pseudo_header->sess = $2;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $4;
+  parser_state->wirelen = $8;
+  parser_state->caplen = $8;
+  parser_state->secs = $6;
+  parser_state->usecs = $7;
+  if (parser_state->pseudo_header != NULL) {
+    /* parser_state->pseudo_header->user is set in ascend_scanner.l */
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $2;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $4;
   }
 }
 ;
@@ -321,17 +337,17 @@ wdp7_hdr: wds_prefix decnum KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD
 /* XMIT-44: (task "freedm_task" at 0xe051fd10, time: 6258.66) 29 octets @ 0x606d1f00 */
 /*              1        2       3      4       5      6      7       8      9      10     11      12 */
 wdp8_hdr: wds_prefix decnum KEYWORD string KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $10;
-  caplen = $10;
-  secs = $8;
-  usecs = $9;
-  if (pseudo_header != NULL) {
-    /* pseudo_header->user is set in ascend_scanner.l */
-    pseudo_header->type = $1;
-    pseudo_header->sess = $2;
-    pseudo_header->call_num[0] = '\0';
-    pseudo_header->chunk = 0;
-    pseudo_header->task = $6;
+  parser_state->wirelen = $10;
+  parser_state->caplen = $10;
+  parser_state->secs = $8;
+  parser_state->usecs = $9;
+  if (parser_state->pseudo_header != NULL) {
+    /* parser_state->pseudo_header->user is set in ascend_scanner.l */
+    parser_state->pseudo_header->type = $1;
+    parser_state->pseudo_header->sess = $2;
+    parser_state->pseudo_header->call_num[0] = '\0';
+    parser_state->pseudo_header->chunk = 0;
+    parser_state->pseudo_header->task = $6;
   }
 }
 ;
@@ -356,7 +372,8 @@ wdd_date: WDD_DATE decnum decnum decnum KEYWORD decnum decnum decnum KEYWORD str
   wddt.tm_year = ($4 > 1970) ? $4 - 1900 : 70;
   wddt.tm_isdst = -1;
 
-  start_time = (guint32) mktime(&wddt);
+  parser_state->timestamp = (guint32) mktime(&wddt);
+  parser_state->saw_timestamp = TRUE;
 }
 ;
 
@@ -366,17 +383,17 @@ WD_DIALOUT_DISP: chunk 2515EE type IP.
 */
 /*           1        2      3       4       5      6       7      8      9      10     11*/
 wdd_hdr: WDD_CHUNK hexnum KEYWORD KEYWORD hexnum KEYWORD decnum decnum decnum KEYWORD HEXNUM {
-  wirelen = $9;
-  caplen = $9;
-  secs = $7;
-  usecs = $8;
-  if (pseudo_header != NULL) {
-    /* pseudo_header->call_num is set in ascend_scanner.l */
-    pseudo_header->type = ASCEND_PFX_WDD;
-    pseudo_header->user[0] = '\0';
-    pseudo_header->sess = 0;
-    pseudo_header->chunk = $2;
-    pseudo_header->task = $5;
+  parser_state->wirelen = $9;
+  parser_state->caplen = $9;
+  parser_state->secs = $7;
+  parser_state->usecs = $8;
+  if (parser_state->pseudo_header != NULL) {
+    /* parser_state->pseudo_header->call_num is set in ascend_scanner.l */
+    parser_state->pseudo_header->type = ASCEND_PFX_WDD;
+    parser_state->pseudo_header->user[0] = '\0';
+    parser_state->pseudo_header->sess = 0;
+    parser_state->pseudo_header->chunk = $2;
+    parser_state->pseudo_header->task = $5;
   }
 }
 ;
@@ -384,16 +401,16 @@ wdd_hdr: WDD_CHUNK hexnum KEYWORD KEYWORD hexnum KEYWORD decnum decnum decnum KE
 byte: HEXBYTE {
   /* remember the position of the data group in the trace, to tip
      off ascend_seek() as to where to look for the next header. */
-  if (first_hexbyte == 0)
-    first_hexbyte = file_tell(fh);
+  if (parser_state->first_hexbyte == 0)
+    parser_state->first_hexbyte = file_tell(fh);
 
-  if (bcur < caplen) {
-    pkt_data[bcur] = $1;
-    bcur++;
+  if (parser_state->bcur < parser_state->caplen) {
+    parser_state->pkt_data[parser_state->bcur] = $1;
+    parser_state->bcur++;
   }
 
   /* arbitrary safety maximum... */
-  if (bcur >= ASCEND_MAX_PKT_LEN)
+  if (parser_state->bcur >= ASCEND_MAX_PKT_LEN)
     YYACCEPT;
 }
 ;
@@ -431,27 +448,42 @@ datagroup: dataln
 
 %%
 
-void
-init_parse_ascend(void)
-{
-  start_time = 0;	/* we haven't see a date/time yet */
-}
-
 /* Run the parser. */
-static int
-run_ascend_parser(FILE_T fh, struct wtap_pkthdr *phdr, guint8 *pd)
+int
+run_ascend_parser(FILE_T fh, struct wtap_pkthdr *phdr, guint8 *pd,
+                  ascend_state_t *parser_state, int *err, gchar **err_info)
 {
-  /* yydebug = 1; */
+  yyscan_t scanner = NULL;
   int retval;
 
-  ascend_init_lexer(fh);
-  pseudo_header = &phdr->pseudo_header.ascend;
-  pkt_data = pd;
+  if (ascendlex_init(&scanner) != 0) {
+    /* errno is set if this fails */
+    *err = errno;
+    *err_info = NULL;
+    return 1;
+  }
+  /* Associate the parser state with the lexical analyzer state */
+  ascendset_extra(parser_state, scanner);
+  parser_state->fh = fh;
+  parser_state->ascend_parse_error = NULL;
+  parser_state->err = err;
+  parser_state->err_info = err_info;
+  parser_state->pseudo_header = &phdr->pseudo_header.ascend;
+  parser_state->pkt_data = pd;
+
+  /*
+   * We haven't seen a time stamp yet.
+   */
+  parser_state->saw_timestamp = FALSE;
+  parser_state->timestamp = 0;
 
-  bcur = 0;
-  first_hexbyte = 0;
-  wirelen = 0;
-  caplen = 0;
+  parser_state->bcur = 0;
+  parser_state->first_hexbyte = 0;
+  parser_state->wirelen = 0;
+  parser_state->caplen = 0;
+
+  parser_state->secs = 0;
+  parser_state->usecs = 0;
 
   /*
    * Not all packets in a "wdd" dump necessarily have a "Cause an
@@ -464,125 +496,16 @@ run_ascend_parser(FILE_T fh, struct wtap_pkthdr *phdr, guint8 *pd)
    * phone number from the last call, and remember that for use
    * when doing random access.
    */
-  pseudo_header->call_num[0] = '\0';
-
-  retval = yyparse(fh);
-
-  caplen = bcur;
+  parser_state->pseudo_header->call_num[0] = '\0';
 
+  retval = yyparse(scanner, parser_state, fh);
+  if (retval == 0)
+    parser_state->caplen = parser_state->bcur;
   return retval;
 }
 
-/* Parse the capture file.
-   Returns:
-     TRUE if we got a packet
-     FALSE otherwise. */
-gboolean
-check_ascend(FILE_T fh, struct wtap_pkthdr *phdr)
-{
-  guint8 buf[ASCEND_MAX_PKT_LEN];
-
-  run_ascend_parser(fh, phdr, buf);
-  
-  /* if we got at least some data, return success even if the parser
-     reported an error. This is because the debug header gives the number
-     of bytes on the wire, not actually how many bytes are in the trace.
-     We won't know where the data ends until we run into the next packet. */
-  return (caplen != 0);
-}
-
-/* Parse the capture file.
-   Returns:
-     PARSED_RECORD if we got a packet
-     PARSED_NONRECORD if the parser succeeded but didn't see a packet
-     PARSE_FAILED if the parser failed. */
-parse_t
-parse_ascend(ascend_t *ascend, FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf,
-             guint length)
-{
-  int retval;
-
-  ws_buffer_assure_space(buf, length);
-  retval = run_ascend_parser(fh, phdr, ws_buffer_start_ptr(buf));
-
-  /* did we see any data (hex bytes)? if so, tip off ascend_seek()
-     as to where to look for the next packet, if any. If we didn't,
-     maybe this record was broken. Advance so we don't get into
-     an infinite loop reading a broken trace. */
-  if (first_hexbyte) {
-    ascend->next_packet_seek_start = first_hexbyte;
-  } else {
-    /* Sometimes, a header will be printed but the data will be omitted, or
-       worse -- two headers will be printed, followed by the data for each.
-       Because of this, we need to be fairly tolerant of what we accept
-       here.  If we didn't find any hex bytes, skip over what we've read so
-       far so we can try reading a new packet. */
-    ascend->next_packet_seek_start = file_tell(fh);
-    retval = 0;
-  }
-
-  /* if we got at least some data, return success even if the parser
-     reported an error. This is because the debug header gives the number
-     of bytes on the wire, not actually how many bytes are in the trace.
-     We won't know where the data ends until we run into the next packet. */
-  if (caplen) {
-    if (! ascend->adjusted) {
-      ascend->adjusted = TRUE;
-      if (start_time != 0) {
-        /*
-         * Capture file contained a date and time.
-         * We do this only if this is the very first packet we've seen -
-         * i.e., if "ascend->adjusted" is false - because
-         * if we get a date and time after the first packet, we can't
-         * go back and adjust the time stamps of the packets we've already
-         * processed, and basing the time stamps of this and following
-         * packets on the time stamp from the file text rather than the
-         * ctime of the capture file means times before this and after
-         * this can't be compared.
-         */
-        ascend->inittime = start_time;
-      }
-      if (ascend->inittime > secs)
-        ascend->inittime -= secs;
-    }
-    phdr->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
-    phdr->ts.secs = secs + ascend->inittime;
-    phdr->ts.nsecs = usecs * 1000;
-    phdr->caplen = caplen;
-    phdr->len = wirelen;
- 
-    /*
-     * For these types, the encapsulation we use is not WTAP_ENCAP_ASCEND,
-     * so set the pseudo-headers appropriately for the type (WTAP_ENCAP_ISDN
-     * or WTAP_ENCAP_ETHERNET).
-     */
-    switch(phdr->pseudo_header.ascend.type) {
-      case ASCEND_PFX_ISDN_X:
-        phdr->pseudo_header.isdn.uton = TRUE;
-        phdr->pseudo_header.isdn.channel = 0;
-        break;
-
-      case ASCEND_PFX_ISDN_R:
-        phdr->pseudo_header.isdn.uton = FALSE;
-        phdr->pseudo_header.isdn.channel = 0;
-        break;
-
-      case ASCEND_PFX_ETHER:
-        phdr->pseudo_header.eth.fcs_len = 0;
-        break;
-    }
-    return PARSED_RECORD;
-  }
-
-  /* Didn't see any data. Still, perhaps the parser was happy.  */
-  if (retval)
-    return PARSE_FAILED;
-  else
-    return PARSED_NONRECORD;
-}
-
 void
-yyerror (FILE_T fh _U_, const char *s)
+yyerror (void *yyscanner, ascend_state_t *state _U_, FILE_T fh _U_, const char *s)
 {
-  ascend_parse_error = s;
+  ascendget_extra(yyscanner)->ascend_parse_error = s;
 }