src/src/debug.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 #include "exim.h"
  10
  11 static uschar  debug_buffer[2048];
  12 static uschar *debug_ptr = debug_buffer;
  13 static int     debug_prefix_length = 0;
  14
  15
  16
  17 /*************************************************
  18 *               Print tree                       *
  19 *************************************************/
  20
  21 /* Recursive tree-printing subroutine. It uses a static vector of uschar to
  22 hold the line-drawing characters that need to be printed on every line as it
  23 moves down the page. This function is used only in debugging circumstances. The
  24 output is done via debug_printf(). */
  25
  26 #define tree_printlinesize 132   /* line size for printing */
  27 static uschar tree_printline[tree_printlinesize];
  28
  29 /* Internal recursive subroutine.
  30
  31 Arguments:
  32   p          tree node
  33   pos        amount of indenting & vertical bars to print
  34   barswitch  if TRUE print | at the pos value
  35
  36 Returns:     nothing
  37 */
  38
  39 static void
  40 tree_printsub(tree_node *p, int pos, int barswitch)
  41 {
  42 int i;
  43 if (p->right != NULL) tree_printsub(p->right, pos+2, 1);
  44 for (i = 0; i <= pos-1; i++) debug_printf("%c", tree_printline[i]);
  45 debug_printf("-->%s [%d]\n", p->name, p->balance);
  46 tree_printline[pos] = barswitch? '|' : ' ';
  47 if (p->left != NULL)
  48   {
  49   tree_printline[pos+2] = '|';
  50   tree_printsub(p->left, pos+2, 0);
  51   }
  52 }
  53
  54 /* The external function, with just a tree node argument. */
  55
  56 void
  57 debug_print_tree(tree_node *p)
  58 {
  59 int i;
  60 for (i = 0; i < tree_printlinesize; i++) tree_printline[i] = ' ';
  61 if (p == NULL) debug_printf("Empty Tree\n"); else tree_printsub(p, 0, 0);
  62 debug_printf("---- End of tree ----\n");
  63 }
  64
  65
  66
  67 /*************************************************
  68 *          Print an argv vector                  *
  69 *************************************************/
  70
  71 /* Called when about to obey execv().
  72
  73 Argument:    the argv vector
  74 Returns:     nothing
  75 */
  76
  77 void
  78 debug_print_argv(const uschar ** argv)
  79 {
  80 debug_printf("exec");
  81 while (*argv != NULL) debug_printf(" %.256s", *argv++);
  82 debug_printf("\n");
  83 }
  84
  85
  86
  87 /*************************************************
  88 *      Expand and print debugging string         *
  89 *************************************************/
  90
  91 /* The string is expanded and written as debugging output. If
  92 expansion fails, a message is written instead.
  93
  94 Argument:    the string
  95 Returns:     nothing
  96 */
  97
  98 void
  99 debug_print_string(uschar *debug_string)
 100 {
 101 if (debug_string == NULL) return;
 102 HDEBUG(D_any|D_v)
 103   {
 104   uschar *s = expand_string(debug_string);
 105   if (s == NULL)
 106     debug_printf("failed to expand debug_output \"%s\": %s\n", debug_string,
 107       expand_string_message);
 108   else if (s[0] != 0)
 109     debug_printf("%s%s", s, (s[Ustrlen(s)-1] == '\n')? "" : "\n");
 110   }
 111 }
 112
 113
 114
 115 /*************************************************
 116 *      Print current uids and gids               *
 117 *************************************************/
 118
 119 /*
 120 Argument:   an introductory string
 121 Returns:    nothing
 122 */
 123
 124 void
 125 debug_print_ids(uschar *s)
 126 {
 127 debug_printf("%s uid=%ld gid=%ld euid=%ld egid=%ld\n", s,
 128   (long int)getuid(), (long int)getgid(), (long int)geteuid(),
 129   (long int)getegid());
 130 }
 131
 132
 133
 134
 135 /*************************************************
 136 *           Print debugging message              *
 137 *************************************************/
 138
 139 /* There are two entries, one for use when being called directly from a
 140 function with a variable argument list.
 141
 142 If debug_pid is nonzero, print the pid at the start of each line. This is for
 143 tidier output when running parallel remote deliveries with debugging turned on.
 144 Must do the whole thing with a single printf and flush, as otherwise output may
 145 get interleaved. Since some calls to debug_printf() don't end with newline,
 146 we save up the text until we do get the newline.
 147 Take care to not disturb errno. */
 148
 149 void
 150 debug_printf(const char *format, ...)
 151 {
 152 va_list ap;
 153 va_start(ap, format);
 154 debug_vprintf(format, ap);
 155 va_end(ap);
 156 }
 157
 158 void
 159 debug_vprintf(const char *format, va_list ap)
 160 {
 161 int save_errno = errno;
 162
 163 if (!debug_file) return;
 164
 165 /* Various things can be inserted at the start of a line. Don't use the
 166 tod_stamp() function for the timestamp, because that will overwrite the
 167 timestamp buffer, which may contain something useful. (This was a bug fix: the
 168 +memory debugging with +timestamp did cause a problem.) */
 169
 170 if (debug_ptr == debug_buffer)
 171   {
 172   DEBUG(D_timestamp)
 173     {
 174     time_t now = time(NULL);
 175     struct tm *t = timestamps_utc? gmtime(&now) : localtime(&now);
 176     (void) sprintf(CS debug_ptr, "%02d:%02d:%02d ", t->tm_hour, t->tm_min,
 177       t->tm_sec);
 178     while(*debug_ptr != 0) debug_ptr++;
 179     }
 180
 181   DEBUG(D_pid)
 182     {
 183     sprintf(CS debug_ptr, "%5d ", (int)getpid());
 184     while(*debug_ptr != 0) debug_ptr++;
 185     }
 186
 187   /* Set up prefix if outputting for host checking and not debugging */
 188
 189   if (host_checking && debug_selector == 0)
 190     {
 191     Ustrcpy(debug_ptr, ">>> ");
 192     debug_ptr += 4;
 193     }
 194
 195   debug_prefix_length = debug_ptr - debug_buffer;
 196   }
 197
 198 /* Use the checked formatting routine to ensure that the buffer
 199 does not overflow. Ensure there's space for a newline at the end. */
 200
 201 if (!string_vformat(debug_ptr,
 202      sizeof(debug_buffer) - (debug_ptr - debug_buffer) - 1, format, ap))
 203   {
 204   uschar *s = US"**** debug string too long - truncated ****\n";
 205   uschar *p = debug_buffer + Ustrlen(debug_buffer);
 206   int maxlen = sizeof(debug_buffer) - Ustrlen(s) - 3;
 207   if (p > debug_buffer + maxlen) p = debug_buffer + maxlen;
 208   if (p > debug_buffer && p[-1] != '\n') *p++ = '\n';
 209   Ustrcpy(p, s);
 210   }
 211
 212 while(*debug_ptr != 0) debug_ptr++;
 213
 214 /* Output the line if it is complete. If we added any prefix data and there
 215 are internal newlines, make sure the prefix is on the continuation lines,
 216 as long as there is room in the buffer. We want to do just a single fprintf()
 217 so as to avoid interleaving. */
 218
 219 if (debug_ptr[-1] == '\n')
 220   {
 221   if (debug_prefix_length > 0)
 222     {
 223     uschar *p = debug_buffer;
 224     int left = sizeof(debug_buffer) - (debug_ptr - debug_buffer) - 1;
 225     while ((p = Ustrchr(p, '\n') + 1) != debug_ptr &&
 226            left >= debug_prefix_length)
 227       {
 228       int len = debug_ptr - p;
 229       memmove(p + debug_prefix_length, p, len + 1);
 230       memmove(p, debug_buffer, debug_prefix_length);
 231       debug_ptr += debug_prefix_length;
 232       left -= debug_prefix_length;
 233       }
 234     }
 235
 236   fprintf(debug_file, "%s", CS debug_buffer);
 237   fflush(debug_file);
 238   debug_ptr = debug_buffer;
 239   debug_prefix_length = 0;
 240   }
 241 errno = save_errno;
 242 }
 243
 244 /* End of debug.c */