/*
** Copyright (C) 2003-2008 Christophe Kalt
**
** This file is part of shush,
** see the LICENSE file for details on your rights.
*/

#include "os.h"

#include <sys/types.h>
#if defined(HAVE_MD5_H)
# include <md5.h>
#endif
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <regex.h>
#if defined(HAVE_PCRE_H)
# include <pcre.h>
#endif

#include "analyzer.h"
#include "byteset.h"
#include "cf.h"
#include "debug.h"
#include "mmap.h"
#include "variable.h"

static char const rcsid[] = "@(#)$Id: analyzer.c 1404 2008-03-08 23:25:46Z kalt $";

time_t out_timestamp, err_timestamp;
size_t out_size, err_size;
char out_md5[33], err_md5[33];

struct condition
{
    int code;
    char *expression;
    union
    {
	regex_t re;
#if defined(HAVE_PCRE_H)
	pcre *pcre;
#endif
    } val;
};

struct marker
{
    size_t offset;
    char type;
};

#define NONE	0
#define LT	0x01 /* Lower Than character may need to be escaped */
#define GT	0x02 /* Grater Than character may need to be escaped */
#define AMP	0x04 /* Lower Than character may need to be escaped */
#define TOGGLE  0x10 /* Toggle rendering */
#define NL      0x40 /* End of line */

#define RE 1
#define PCRE 2

static int outtype, errtype;
static struct condition *out, *err;
static struct marker *outmarks, *errmarks;

/*
** compile_re
**	Regular expression (regex_t) initialization
*/
static int
compile_re(void *reptr, char *str)
{
    regex_t *re;
    int errcode;

    re = reptr;
    errcode = regcomp(re, str, REG_EXTENDED);
    if (errcode != 0)
      {
	char buf[1024];
	
	if (regerror(errcode, re, buf, 1024) != 0)
	    error("Bad regular expression: %s", buf);
	else
	    error("Failed to compile regular expression and to obtain error code: %s", str);
	return -1;
      }
    return 0;
}

#if defined(HAVE_PCRE_H)
/*
** compile_pcre
**	Perl Compatible Regular Expression (pcre) initialization
*/
static int
compile_pcre(void *pcreptr, char *str)
{
    pcre **re;
    const char *errmsg;
    int erroffset;

    re = pcreptr;
    *re = pcre_compile(str, 0, &errmsg, &erroffset, NULL);
    if (*re == NULL)
      {
	error("Bad PCRE (offset %d): %s", erroffset, errmsg);
	return -1;
      }
    return 0;
}
#endif

/*
** loadfile
**	Read a list of one line conditions from a file
*/
static int
loadfile(int *type, char *file, struct condition **list)
{
    int lineno, cond, max;
    size_t len;
    char *str, *ln, *lndup, *nl;

    assert( *list == NULL );

    *type = RE;

    /* Allocate a list of conditions */
    max = 10;
    *list = (struct condition *) malloc(max * sizeof(struct condition));
    if (*list == NULL)
      {
	error("malloc() failed: %s", ERRSTR);
	return -1;
      }
    cond = 0;
    (*list)[cond].code = -1;

    err_timestamp = 0;
    /* Map the configuration file to memory so it can be parsed */
    switch (mapfile(file, -1, (void **)&str, &len))
      {
      case 0:
	  /* OK! */
	  err_timestamp = mapstat()->st_mtime;
	  break;
      case 1:
	  /* ENOENT */
	  return 0;
      default:
	  /* Failure */
	  return -1;
      }

    if (len == 0)
	return 0;

    err_size = len;
    MD5((unsigned char *) str, len, err_md5);

    ln = str; nl = str;
    lineno = 1;
    lndup = NULL;
    while (ln - str < len)
    {
      /* Parse the file line by line */
      while (nl - str < len && *nl != '\n')
	  nl += 1;

      if ((nl - str) == len)
	{
	  if (*(nl - 1) != '\0')
	    {
	      assert( lndup == NULL );
	      lndup = (char *) malloc(len - (ln - str) + 1);
              if (lndup == NULL)
                {
                  error("malloc() failed: %s", ERRSTR);
                  return -1;
                }
	      memcpy(lndup, ln, len - (ln - str));
	      lndup[len - (ln - str)] = '\0';
	      ln = lndup;
	    }
	}
      else
	  *nl = '\0';

      if (*ln == '#')
	{
	  /* Parse configuration directives */
	  if (strcasecmp(ln, "#pcre") == 0)
	    {
	      if (cond != 0)
		{
		  error("\"#pcre\" directive must be specified before any condition.");
		  if (lndup != NULL)
		      free(lndup);
		  return -1;
		}
	      else
	        {
#if defined(HAVE_PCRE_H)
		  *type = PCRE;
#else
		  error("This binary was built without PCRE support.");
		  if (lndup != NULL)
		      free(lndup);
		  return -1;
#endif
		}
	    }
	}
      else
	{
	  /* Make sure the list structure is big enough */
	  if (cond == max-2)
	    {
	      max *= 2;
	      *list = (struct condition *) realloc(*list,
					      max * sizeof(struct condition));
	      if (*list == NULL) /* leakage */
		{
		  error("realloc() failed: %s", ERRSTR);
		  if (lndup != NULL)
		      free(lndup);
		  return -1;
		}
	    }

	  /* Finally, compile the expression */
	  if (*ln != '\0')
	    {
	      (*list)[cond].code = *ln;
	      (*list)[cond].expression = strdup(ln + 1);
	      if ((*list)[cond].expression == NULL)
		{
		  error("strdup() failed: %s", ERRSTR);
		  if (lndup != NULL)
		      free(lndup);
		  return -1;
		}
	      if (*type == RE)
		{
		  if (compile_re((void *) &((*list)[cond].val.re), ln + 1) != 0)
		    {
		      if (lndup != NULL)
			  free(lndup);
		      return -1;
		    }
		}
	      else if (*type == PCRE)
		{
#if defined(HAVE_PCRE_H)
		  if (compile_pcre((void *) &((*list)[cond].val.pcre), ln + 1) != 0)
		    {
		      if (lndup != NULL)
			  free(lndup);
		      return -1;
		    }
#else
		  error("This binary was built without PCRE support.");
		  if (lndup != NULL)
		      free(lndup);
		  return -1;
#endif
		}
	      else
		  abort();
	      cond += 1;
	    }
	}
      ln = nl + 1;
      lineno += 1;
    }

    if (lndup != NULL)
	free(lndup);

    (*list)[cond].code = -1; /* Mark the end of the list */

    if (unmapfile(file, str, len) != 0)
	return -1;

    return 0;
}

/*
** analyzer_init
**	Initialization for the analyzer.
*/
int
analyzer_init(char *outdef, char *errdef)
{
    assert( outdef != NULL && errdef != NULL );

    outmarks = errmarks = NULL;
    if (loadfile(&outtype, outdef, &out) != 0)
	return -1;
    out_timestamp = err_timestamp; err_timestamp = 0;
    out_size = err_size;
    strcpy(out_md5, err_md5);
    if (cf_getrptnum(0, CF_RPTSTDERR) != CF_STDERR_MIXED)
	return loadfile(&errtype, errdef, &err);
    else
	return 0;
}

/*
** grow_marks
**	Grow a list of marker
*/
static void
grow_marks(struct marker **marks, int *max)
{
    struct marker *new;

    *max *= 2;
    new = (struct marker *) realloc(*marks, *max * sizeof(struct marker));
    if (new == NULL)
      {
	error("realloc() failed: %s", ERRSTR);
	free(*marks);
	*marks = NULL;
      }
    else
	*marks = new;
}

/*
** set_mark
**	Set 1 mark
*/
static void
set_mark(struct marker **marks, int *mark, int *max, size_t offset, int type)
{
    int i;

    i = *mark - 1;
    while (i >= 0 && (*marks)[i].offset > offset)
	i -= 1;

    if (i >= 0 && (*marks)[i].offset == offset)
	(*marks)[i].type |= type;
    else
      {
	int j;

	if (*mark == *max-2)
	    grow_marks(marks, max);

	j = *mark;
	while (j > i)
	  {
	    (*marks)[j+1].offset = (*marks)[j].offset;
	    (*marks)[j+1].type = (*marks)[j].type;
	    j -= 1;
	  }
	(*marks)[i+1].type = type;
	(*marks)[i+1].offset = offset;
	*mark += 1;
      }
}

/*
** analyze_file
**	Analyze a file according to user specified regular expressions.
*/
static int
analyze_file(char *str, size_t len, int type,
	     struct condition *list, struct marker **marks)
{
    char *ln, *lndup, *nl;
    int max, mark, lineno, condno;

    assert( type == RE || type == PCRE );
    assert( list != NULL );
    assert( *marks == NULL );

    if (len == 0)
	return 0;

    assert( str != NULL );

    /* Allocate the marks array */
    max = 10;
    *marks = (struct marker *) malloc(max * sizeof(struct marker));
    if (*marks == NULL)
      {
	error("malloc() failed: %s", ERRSTR);
        return -1;
      }        
    mark = 0;
    (*marks)[mark].type = NONE;

    ln = str; nl = str;
    lineno = 0;
    lndup = NULL;
    while (ln - str < len)
    {
      /* Parse the file line by line */
      while (nl - str < len && *nl != '\n' && *nl != '\0')
	{
	  if (*marks != NULL)
	    {
	      if (*nl == '<')
		  set_mark(marks, &mark, &max, nl - str, LT);
	      else if (*nl == '>')
		  set_mark(marks, &mark, &max, nl - str, GT);
	      else if (*nl == '&')
		  set_mark(marks, &mark, &max, nl - str, AMP);
	    }
	  nl += 1;
	}

      if (*nl == '\0')
	  break;

      if (*nl == '\n')
	{
	  set_mark(marks, &mark, &max, nl-str, NL);
	  *nl = '\0';
	}
      lineno += 1;

      if (*nl != '\0' && (nl - str) == len)
	{
	  assert( lndup == NULL );
	  lndup = (char *) malloc(nl - str + 1);
          if (lndup == NULL)
            {
              error("malloc() failed: %s", ERRSTR);
              return -1;
            }
	  memcpy(lndup, ln, nl - str);
	  lndup[nl - str] = '\0';
	  ln = lndup;
	}

      debug(DDATA, "Data line: [%s]", ln);

      condno = 0;
      while (list[condno].code != -1)
	{
	  int r;
	      
	  if (type == RE)
	    {
	      regmatch_t pmatch[1024];

	      r = regexec(&(list[condno].val.re), ln, 1024, pmatch, 0);
	      if (r != 0 && r != REG_NOMATCH)
		{
		  /* Something bad happened */
		  char buf[1024];

		  if (regerror(r, &(list[condno].val.re), buf, 1024) != 0)
		      error("Fatal error during output analysis: regexec() failed: %s", buf);
		  else
		      error("Fatal error during output analysis: regexec() failed with code %d", r);
		  error("Regular expression used was: %s",
			list[condno].expression);
		  error("Trying to match the following line of data: %s", buf);
		  if (lndup != NULL)
		      free(lndup);
		  else
		      *nl = '\n';
		  return -1;
		}
	      else
		{
		  if (r == 0)
		    {
		      /* Matched */
		      debug(DDATA, "Matched: #%d %d[%c] (REG_NOMATCH=%d)",
			    condno+1, r, list[condno].code, REG_NOMATCH);
		      byteset_set(list[condno].code,
				  1 + byteset_get(list[condno].code));
		      /* Check for substrings */
		      r = 1;
		      while (r < 1024)
			{
			  if (pmatch[r].rm_so == -1)
			      break;
			  set_mark(marks, &mark, &max,
				   ln - str + pmatch[r].rm_so, TOGGLE);
			  set_mark(marks, &mark, &max,
				   ln - str + pmatch[r].rm_eo, TOGGLE);
			  r += 1;
			}
		      break;
		    }
		  else
		      debug(DVDATA, "Failed: #%d %d[%c] (REG_NOMATCH=%d)",
			    condno+1, r, list[condno].code, REG_NOMATCH);
		}
	    }
#if defined(HAVE_PCRE_H)
	  else if (type == PCRE)
	    {
	      int ovector[3072];

	      r = pcre_exec(list[condno].val.pcre, NULL, ln,
			    (lndup != NULL) ? strlen(lndup) : nl - ln,
			    0, 0, ovector, 3072);
	      if (r < 0 && r != PCRE_ERROR_NOMATCH)
		{
		  /* Something bad happened */
		  error("Fatal error during output analysis: pcre_exec() failed with code %d", r);
		  error("Regular expression used was: %s",
			list[condno].expression);
		  error("Trying to match the following line of data: %s", ln);
		  if (lndup != NULL)
		      free(lndup);
		  else
		      *nl = '\n';
		  return -1;
		}
	      else
		{
		  if (r >= 0)
		    {
		      int i;

		      /* Matched */
		      debug(DDATA,
			    "Matched: #%d %d[%c] (PCRE_ERROR_NOMATCH=%d)",
			    condno+1, r, list[condno].code, PCRE_ERROR_NOMATCH);
		      byteset_set(list[condno].code, 1);
		      /* Check for substrings */
		      i = 1;
		      while (i < r)
			{
			  if (ovector[i*2] < 0 || ovector[i*2+1] < 0)
			      continue;
			  set_mark(marks, &mark, &max,
				   ln - str + ovector[i*2], TOGGLE);
			  set_mark(marks, &mark, &max,
				   ln - str + ovector[i*2+1], TOGGLE);
			  i += 1;
			}
		      break;
		    }
		  else
		      debug(DVDATA,
			    "Failed: #%d %d[%c] (PCRE_ERROR_NOMATCH=%d)",
			    condno+1, r, list[condno].code, PCRE_ERROR_NOMATCH);
		}
	    }
#endif
	  else
	      abort();

	  condno += 1;
	}
      if (list[condno].code == -1)
	  debug(DDATA, "No match!");

      if (lndup == NULL)
	  *nl = '\n';

      ln = ++nl;
    }

    if (lndup != NULL)
	free(lndup);

    return lineno;
}

/*
** analyzer_run
**	Analyze the given files according to user specified regular expressions.
*/
int
analyzer_run(char *ostr, size_t olen, char *estr, size_t elen)
{
    int o, e;

    o = analyze_file(ostr, olen, outtype, out, &outmarks);
    if (estr != NULL)
	e = analyze_file(estr, elen, errtype, err, &errmarks);
    else
	e = 0;

    variable_set(V_LINES, o + e);
    variable_set(V_OUTLINES, o);
    variable_set(V_ERRLINES, e);

    if (o < 0 || e < 0)
	return -1;
    return 0;
}

/*
** output_file
**	Output a single file
*/
static int
output_file(FILE *mail, char *name, int format, size_t limit,
	    char *str, size_t len, struct marker *marks)
{
    size_t ptr;
    char toggle, trunc;

    if (name != NULL)
      {
	if (format == CF_FORMAT_RICH)
	    toggle = fprintf(mail, "<Center>----- <Underline>Command standard %s follows</Underline> -----</Center>", name);
	else if (format == CF_FORMAT_HTML)
	    toggle = fprintf(mail, "<p align=center>----- <em>Command standard %s follows</em> -----</p>", name);
	else
	    toggle = 1;
	if (toggle <= 0)
	  {
	    error("fprintf() failed: %s", ERRSTR);
	    return -1;
	  }
      }

    if (format == CF_FORMAT_RICH && fprintf(mail, "<Nofill>") != 8)
      {
	error("fprintf() failed: %s", ERRSTR);
	return -1;
      }
    if (format == CF_FORMAT_HTML && fprintf(mail, "<pre>") != 5)
      {
	error("fprintf() failed: %s", ERRSTR);
	return -1;
      }
    ptr = 0;
    toggle = 0; trunc = 0;
    while (marks->type != NONE)
      {
	if (marks->offset - ptr > 0)
	  {
	    if (fwrite(str + ptr, marks->offset - ptr, 1, mail) != 1)
	      {
		error("fwrite() failed: %s", ERRSTR);
		return -1;
	      }
	    ptr = marks->offset;
	  }

	if (format != CF_FORMAT_TEXT && (marks->type & TOGGLE) == TOGGLE)
	  {
	    char *tag;

	    if (toggle == 0)
		tag = (format == CF_FORMAT_RICH) ? "<Bold>" : "<b>";
	    else
		tag = (format == CF_FORMAT_RICH) ? "</Bold>" : "</b>";

	    if (fprintf(mail, tag) != strlen(tag))
	      {
		error("fprintf() failed: %s", ERRSTR);
		return -1;
	      }
	    toggle = 1 - toggle;
	  }

	if (format == CF_FORMAT_HTML && (marks->type & (LT|GT|AMP)) != 0)
	  {
	    char *esc;

	    if ((marks->type & LT) == LT)
		esc = "&lt;";
	    else if ((marks->type & GT) == GT)
		esc = "&gt;";
	    else if ((marks->type & AMP) == AMP)
		esc = "&amp;";
	    else
		abort();

	    if (fprintf(mail, esc) != strlen(esc))
	      {
		error("fprintf() failed: %s", ERRSTR);
		return -1;
	      }

	    /* Skip the character, it was escaped! */
	    ptr += 1;
	  }

	if (format == CF_FORMAT_RICH && (marks->type & LT) == LT
	    && fprintf(mail, "<") != 1)
	  {
	    error("fprintf() failed: %s", ERRSTR);
	    return -1;
	  }

	if (trunc == 0 && (marks->type & NL) == NL)
	  {
	    if (len > limit && marks->offset > limit / 2)
	      {
		struct marker *hole;
		u_long lines;

		lines = 0;
		hole = marks;
		while ((marks->type & NL) != NL
		       || hole->offset + len - marks->offset > limit)
		  {
		    if ((marks->type & NL) == NL)
			lines += 1;
		    marks += 1;
		  }

		if (format == CF_FORMAT_TEXT
		    && fprintf(mail, "\n[... %lu lines (%ld bytes) of output truncated ...]\n", lines, marks->offset - hole->offset) <=0 )
		  {
		    error("fprintf() failed: %s", ERRSTR);
		    return -1;
		  }		
		if (format == CF_FORMAT_RICH
		    && fprintf(mail, "</Nofill><Center>----- <Underline>%lu lines (%ld bytes) of output truncated</Underline> -----</Center><Nofill>", lines, marks->offset - hole->offset) <= 0)
		  {
		    error("fprintf() failed: %s", ERRSTR);
		    return -1;
		  }
		if (format == CF_FORMAT_HTML
		    && fprintf(mail, "</pre><p align=center>----- <em>%lu lines (%ld bytes) of output truncated</em> -----</p><pre>", lines, marks->offset - hole->offset) <= 0)
		  {
		    error("fprintf() failed: %s", ERRSTR);
		    return -1;
		  }		

		ptr = marks->offset + 1;
		trunc = 1;
	      }
	  }

	marks += 1;
      }

    if (ptr < len && fwrite(str + ptr, len - ptr, 1, mail) != 1)
      {
	error("fwrite() failed: %s", ERRSTR);
	return -1;
      }
    if (str[len - 1] != '\n' && fprintf(mail, "\n") != 1)
      {
	error("fprintf() failed: %s", ERRSTR);
	return -1;
      }

    if (format == CF_FORMAT_RICH && fprintf(mail, "</Nofill>") != 9)
      {
	error("fprintf() failed: %s", ERRSTR);
	return -1;
      }
    if (format == CF_FORMAT_HTML && fprintf(mail, "</pre>") != 6)
      {
	error("fprintf() failed: %s", ERRSTR);
	return -1;
      }
	
    return 0;
}

/*
** analyzer_output
**	Output the result of an analysis
*/
int
analyzer_output(FILE *mail, int format, int output, size_t limit,
		char *ostr, size_t olen, char *estr, size_t elen)
{
    size_t olimit, elimit;
    int o, e, over;

    over = 0;
    if (limit <= 0)
	olimit = elimit = olen + elen;
    else if (output == CF_STDERR_OUT)
      {
        olimit = elimit = limit;
        if (olen > limit)
            over = 1;
      }
    else if (output == CF_STDERR_ERR)
      {
        olimit = elimit = limit;
        if (elen > limit)
            over = 1;
      }
    else
      {
	if (output == CF_STDERR_MIXED)
	    olimit = limit;
	else 
	  {
	    olimit = elimit = limit / 2;
	    if (olen < olimit)
		elimit = limit - olen;
	    if (elen < elimit)
		olimit = limit - elen;
	  }
        if (olen + elen > limit)
            over = 1;
      }

    if (over == 1)
      {
	if (format == CF_FORMAT_TEXT
	    && fprintf(mail, "WARNING: The following output is truncated!\n         (Total of %ld bytes is over the limit of %ld)\n\n", olen + elen, limit) <= 0)
	  {
	    error("fprintf() failed: %s", ERRSTR);
	    return -1;
	  }		
	if (format == CF_FORMAT_RICH
	    && fprintf(mail, "<Nofill><Bold>WARNING</Bold>: The following output is truncated!\n         (Total of %ld bytes is over the limit of %ld)</Nofill>\n\n", olen + elen, limit) <= 0)
	  {
	    error("fprintf() failed: %s", ERRSTR);
	    return -1;
	  }
	if (format == CF_FORMAT_HTML
	    && fprintf(mail, "<p><b>WARNING</b>: The following output is truncated! (Total of %ld bytes is over the limit of %ld)</p>", olen + elen, limit) <= 0)
	  {
	    error("fprintf() failed: %s", ERRSTR);
	    return -1;
	  }		
      }

    o = e = 0;
    if (output == CF_STDERR_ERR)
      {
        if (elen > 0)
            e = output_file(mail, "error ", format, elimit,
                            estr, elen, errmarks);
      }
    else if (output == CF_STDERR_OUT)
      {
        if (olen > 0)
            o = output_file(mail, "output ", format, olimit,
                            ostr, olen, outmarks);
      }
    else
      {
        if (elen > 0 && output == CF_STDERR_FIRST)
            e = output_file(mail, (olen > 0) ? "error " : NULL,
                            format, elimit, estr, elen, errmarks);
        if (olen > 0)
            o = output_file(mail, (output != CF_STDERR_MIXED
                                   && elen > 0) ? "output" : NULL,
                            format, olimit, ostr, olen, outmarks);
        
        if (elen > 0 && output == CF_STDERR_LAST)
            e = output_file(mail, (olen > 0) ? "error " : NULL,
                            format, elimit, estr, elen, errmarks);
      }

    if (o != 0 || e != 0)
	return -1;
    return 0;
}