git.distorted.org.uk Git - u/mdw/putty/blob - logging.c

   1 /*
   2  * Session logging.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <ctype.h>
   8
   9 #include <time.h>
  10 #include <assert.h>
  11
  12 #include "putty.h"
  13
  14 /* log session to file stuff ... */
  15 struct LogContext {
  16     FILE *lgfp;
  17     enum { L_CLOSED, L_OPENING, L_OPEN, L_ERROR } state;
  18     bufchain queue;
  19     Filename *currlogfilename;
  20     void *frontend;
  21     Conf *conf;
  22     int logtype;                       /* cached out of conf */
  23 };
  24
  25 static Filename *xlatlognam(Filename *s, char *hostname, struct tm *tm);
  26
  27 /*
  28  * Internal wrapper function which must be called for _all_ output
  29  * to the log file. It takes care of opening the log file if it
  30  * isn't open, buffering data if it's in the process of being
  31  * opened asynchronously, etc.
  32  */
  33 static void logwrite(struct LogContext *ctx, void *data, int len)
  34 {
  35     /*
  36      * In state L_CLOSED, we call logfopen, which will set the state
  37      * to one of L_OPENING, L_OPEN or L_ERROR. Hence we process all of
  38      * those three _after_ processing L_CLOSED.
  39      */
  40     if (ctx->state == L_CLOSED)
  41         logfopen(ctx);
  42
  43     if (ctx->state == L_OPENING) {
  44         bufchain_add(&ctx->queue, data, len);
  45     } else if (ctx->state == L_OPEN) {
  46         assert(ctx->lgfp);
  47         if (fwrite(data, 1, len, ctx->lgfp) < (size_t)len) {
  48             logfclose(ctx);
  49             ctx->state = L_ERROR;
  50             /* Log state is L_ERROR so this won't cause a loop */
  51             logevent(ctx->frontend,
  52                      "Disabled writing session log due to error while writing");
  53         }
  54     }                                  /* else L_ERROR, so ignore the write */
  55 }
  56
  57 /*
  58  * Convenience wrapper on logwrite() which printf-formats the
  59  * string.
  60  */
  61 static void logprintf(struct LogContext *ctx, const char *fmt, ...)
  62 {
  63     va_list ap;
  64     char *data;
  65
  66     va_start(ap, fmt);
  67     data = dupvprintf(fmt, ap);
  68     va_end(ap);
  69
  70     logwrite(ctx, data, strlen(data));
  71     sfree(data);
  72 }
  73
  74 /*
  75  * Flush any open log file.
  76  */
  77 void logflush(void *handle) {
  78     struct LogContext *ctx = (struct LogContext *)handle;
  79     if (ctx->logtype > 0)
  80         if (ctx->state == L_OPEN)
  81             fflush(ctx->lgfp);
  82 }
  83
  84 static void logfopen_callback(void *handle, int mode)
  85 {
  86     struct LogContext *ctx = (struct LogContext *)handle;
  87     char buf[256], *event;
  88     struct tm tm;
  89     const char *fmode;
  90
  91     if (mode == 0) {
  92         ctx->state = L_ERROR;          /* disable logging */
  93     } else {
  94         fmode = (mode == 1 ? "ab" : "wb");
  95         ctx->lgfp = f_open(ctx->currlogfilename, fmode, FALSE);
  96         if (ctx->lgfp)
  97             ctx->state = L_OPEN;
  98         else
  99             ctx->state = L_ERROR;
 100     }
 101
 102     if (ctx->state == L_OPEN) {
 103         /* Write header line into log file. */
 104         tm = ltime();
 105         strftime(buf, 24, "%Y.%m.%d %H:%M:%S", &tm);
 106         logprintf(ctx, "=~=~=~=~=~=~=~=~=~=~=~= PuTTY log %s"
 107                   " =~=~=~=~=~=~=~=~=~=~=~=\r\n", buf);
 108     }
 109
 110     event = dupprintf("%s session log (%s mode) to file: %s",
 111                       ctx->state == L_ERROR ?
 112                       (mode == 0 ? "Disabled writing" : "Error writing") :
 113                       (mode == 1 ? "Appending" : "Writing new"),
 114                       (ctx->logtype == LGTYP_ASCII ? "ASCII" :
 115                        ctx->logtype == LGTYP_DEBUG ? "raw" :
 116                        ctx->logtype == LGTYP_PACKETS ? "SSH packets" :
 117                        ctx->logtype == LGTYP_SSHRAW ? "SSH raw data" :
 118                        "unknown"),
 119                       filename_to_str(ctx->currlogfilename));
 120     logevent(ctx->frontend, event);
 121     sfree(event);
 122
 123     /*
 124      * Having either succeeded or failed in opening the log file,
 125      * we should write any queued data out.
 126      */
 127     assert(ctx->state != L_OPENING);   /* make _sure_ it won't be requeued */
 128     while (bufchain_size(&ctx->queue)) {
 129         void *data;
 130         int len;
 131         bufchain_prefix(&ctx->queue, &data, &len);
 132         logwrite(ctx, data, len);
 133         bufchain_consume(&ctx->queue, len);
 134     }
 135 }
 136
 137 /*
 138  * Open the log file. Takes care of detecting an already-existing
 139  * file and asking the user whether they want to append, overwrite
 140  * or cancel logging.
 141  */
 142 void logfopen(void *handle)
 143 {
 144     struct LogContext *ctx = (struct LogContext *)handle;
 145     struct tm tm;
 146     int mode;
 147
 148     /* Prevent repeat calls */
 149     if (ctx->state != L_CLOSED)
 150         return;
 151
 152     if (!ctx->logtype)
 153         return;
 154
 155     tm = ltime();
 156
 157     /* substitute special codes in file name */
 158     if (ctx->currlogfilename)
 159         filename_free(ctx->currlogfilename);
 160     ctx->currlogfilename =
 161         xlatlognam(conf_get_filename(ctx->conf, CONF_logfilename),
 162                    conf_get_str(ctx->conf, CONF_host), &tm);
 163
 164     ctx->lgfp = f_open(ctx->currlogfilename, "r", FALSE);  /* file already present? */
 165     if (ctx->lgfp) {
 166         int logxfovr = conf_get_int(ctx->conf, CONF_logxfovr);
 167         fclose(ctx->lgfp);
 168         if (logxfovr != LGXF_ASK) {
 169             mode = ((logxfovr == LGXF_OVR) ? 2 : 1);
 170         } else
 171             mode = askappend(ctx->frontend, ctx->currlogfilename,
 172                              logfopen_callback, ctx);
 173     } else
 174         mode = 2;                      /* create == overwrite */
 175
 176     if (mode < 0)
 177         ctx->state = L_OPENING;
 178     else
 179         logfopen_callback(ctx, mode);  /* open the file */
 180 }
 181
 182 void logfclose(void *handle)
 183 {
 184     struct LogContext *ctx = (struct LogContext *)handle;
 185     if (ctx->lgfp) {
 186         fclose(ctx->lgfp);
 187         ctx->lgfp = NULL;
 188     }
 189     ctx->state = L_CLOSED;
 190 }
 191
 192 /*
 193  * Log session traffic.
 194  */
 195 void logtraffic(void *handle, unsigned char c, int logmode)
 196 {
 197     struct LogContext *ctx = (struct LogContext *)handle;
 198     if (ctx->logtype > 0) {
 199         if (ctx->logtype == logmode)
 200             logwrite(ctx, &c, 1);
 201     }
 202 }
 203
 204 /*
 205  * Log an Event Log entry. Used in SSH packet logging mode; this is
 206  * also as convenient a place as any to put the output of Event Log
 207  * entries to stderr when a command-line tool is in verbose mode.
 208  * (In particular, this is a better place to put it than in the
 209  * front ends, because it only has to be done once for all
 210  * platforms. Platforms which don't have a meaningful stderr can
 211  * just avoid defining FLAG_STDERR.
 212  */
 213 void log_eventlog(void *handle, const char *event)
 214 {
 215     struct LogContext *ctx = (struct LogContext *)handle;
 216     if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) {
 217         fprintf(stderr, "%s\n", event);
 218         fflush(stderr);
 219     }
 220     /* If we don't have a context yet (eg winnet.c init) then skip entirely */
 221     if (!ctx)
 222         return;
 223     if (ctx->logtype != LGTYP_PACKETS &&
 224         ctx->logtype != LGTYP_SSHRAW)
 225         return;
 226     logprintf(ctx, "Event Log: %s\r\n", event);
 227     logflush(ctx);
 228 }
 229
 230 /*
 231  * Log an SSH packet.
 232  * If n_blanks != 0, blank or omit some parts.
 233  * Set of blanking areas must be in increasing order.
 234  */
 235 void log_packet(void *handle, int direction, int type,
 236                 char *texttype, const void *data, int len,
 237                 int n_blanks, const struct logblank_t *blanks,
 238                 const unsigned long *seq)
 239 {
 240     struct LogContext *ctx = (struct LogContext *)handle;
 241     char dumpdata[80], smalldata[5];
 242     int p = 0, b = 0, omitted = 0;
 243     int output_pos = 0; /* NZ if pending output in dumpdata */
 244
 245     if (!(ctx->logtype == LGTYP_SSHRAW ||
 246           (ctx->logtype == LGTYP_PACKETS && texttype)))
 247         return;
 248
 249     /* Packet header. */
 250     if (texttype) {
 251         if (seq) {
 252             logprintf(ctx, "%s packet #0x%lx, type %d / 0x%02x (%s)\r\n",
 253                       direction == PKT_INCOMING ? "Incoming" : "Outgoing",
 254                       *seq, type, type, texttype);
 255         } else {
 256             logprintf(ctx, "%s packet type %d / 0x%02x (%s)\r\n",
 257                       direction == PKT_INCOMING ? "Incoming" : "Outgoing",
 258                       type, type, texttype);
 259         }
 260     } else {
 261         /*
 262          * Raw data is logged with a timestamp, so that it's possible
 263          * to determine whether a mysterious delay occurred at the
 264          * client or server end. (Timestamping the raw data avoids
 265          * cluttering the normal case of only logging decrypted SSH
 266          * messages, and also adds conceptual rigour in the case where
 267          * an SSH message arrives in several pieces.)
 268          */
 269         char buf[256];
 270         struct tm tm;
 271         tm = ltime();
 272         strftime(buf, 24, "%Y-%m-%d %H:%M:%S", &tm);
 273         logprintf(ctx, "%s raw data at %s\r\n",
 274                   direction == PKT_INCOMING ? "Incoming" : "Outgoing",
 275                   buf);
 276     }
 277
 278     /*
 279      * Output a hex/ASCII dump of the packet body, blanking/omitting
 280      * parts as specified.
 281      */
 282     while (p < len) {
 283         int blktype;
 284
 285         /* Move to a current entry in the blanking array. */
 286         while ((b < n_blanks) &&
 287                (p >= blanks[b].offset + blanks[b].len))
 288             b++;
 289         /* Work out what type of blanking to apply to
 290          * this byte. */
 291         blktype = PKTLOG_EMIT; /* default */
 292         if ((b < n_blanks) &&
 293             (p >= blanks[b].offset) &&
 294             (p < blanks[b].offset + blanks[b].len))
 295             blktype = blanks[b].type;
 296
 297         /* If we're about to stop omitting, it's time to say how
 298          * much we omitted. */
 299         if ((blktype != PKTLOG_OMIT) && omitted) {
 300             logprintf(ctx, "  (%d byte%s omitted)\r\n",
 301                       omitted, (omitted==1?"":"s"));
 302             omitted = 0;
 303         }
 304
 305         /* (Re-)initialise dumpdata as necessary
 306          * (start of row, or if we've just stopped omitting) */
 307         if (!output_pos && !omitted)
 308             sprintf(dumpdata, "  %08x%*s\r\n", p-(p%16), 1+3*16+2+16, "");
 309
 310         /* Deal with the current byte. */
 311         if (blktype == PKTLOG_OMIT) {
 312             omitted++;
 313         } else {
 314             int c;
 315             if (blktype == PKTLOG_BLANK) {
 316                 c = 'X';
 317                 sprintf(smalldata, "XX");
 318             } else {  /* PKTLOG_EMIT */
 319                 c = ((unsigned char *)data)[p];
 320                 sprintf(smalldata, "%02x", c);
 321             }
 322             dumpdata[10+2+3*(p%16)] = smalldata[0];
 323             dumpdata[10+2+3*(p%16)+1] = smalldata[1];
 324             dumpdata[10+1+3*16+2+(p%16)] = (isprint(c) ? c : '.');
 325             output_pos = (p%16) + 1;
 326         }
 327
 328         p++;
 329
 330         /* Flush row if necessary */
 331         if (((p % 16) == 0) || (p == len) || omitted) {
 332             if (output_pos) {
 333                 strcpy(dumpdata + 10+1+3*16+2+output_pos, "\r\n");
 334                 logwrite(ctx, dumpdata, strlen(dumpdata));
 335                 output_pos = 0;
 336             }
 337         }
 338
 339     }
 340
 341     /* Tidy up */
 342     if (omitted)
 343         logprintf(ctx, "  (%d byte%s omitted)\r\n",
 344                   omitted, (omitted==1?"":"s"));
 345     logflush(ctx);
 346 }
 347
 348 void *log_init(void *frontend, Conf *conf)
 349 {
 350     struct LogContext *ctx = snew(struct LogContext);
 351     ctx->lgfp = NULL;
 352     ctx->state = L_CLOSED;
 353     ctx->frontend = frontend;
 354     ctx->conf = conf_copy(conf);
 355     ctx->logtype = conf_get_int(ctx->conf, CONF_logtype);
 356     ctx->currlogfilename = NULL;
 357     bufchain_init(&ctx->queue);
 358     return ctx;
 359 }
 360
 361 void log_free(void *handle)
 362 {
 363     struct LogContext *ctx = (struct LogContext *)handle;
 364
 365     logfclose(ctx);
 366     bufchain_clear(&ctx->queue);
 367     if (ctx->currlogfilename)
 368         filename_free(ctx->currlogfilename);
 369     sfree(ctx);
 370 }
 371
 372 void log_reconfig(void *handle, Conf *conf)
 373 {
 374     struct LogContext *ctx = (struct LogContext *)handle;
 375     int reset_logging;
 376
 377     if (!filename_equal(conf_get_filename(ctx->conf, CONF_logfilename),
 378                         conf_get_filename(conf, CONF_logfilename)) ||
 379         conf_get_int(ctx->conf, CONF_logtype) !=
 380         conf_get_int(conf, CONF_logtype))
 381         reset_logging = TRUE;
 382     else
 383         reset_logging = FALSE;
 384
 385     if (reset_logging)
 386         logfclose(ctx);
 387
 388     conf_free(ctx->conf);
 389     ctx->conf = conf_copy(conf);
 390
 391     ctx->logtype = conf_get_int(ctx->conf, CONF_logtype);
 392
 393     if (reset_logging)
 394         logfopen(ctx);
 395 }
 396
 397 /*
 398  * translate format codes into time/date strings
 399  * and insert them into log file name
 400  *
 401  * "&Y":YYYY   "&m":MM   "&d":DD   "&T":hhmmss   "&h":<hostname>   "&&":&
 402  */
 403 static Filename *xlatlognam(Filename *src, char *hostname, struct tm *tm)
 404 {
 405     char buf[10], *bufp;
 406     int size;
 407     char *buffer;
 408     int buflen, bufsize;
 409     const char *s;
 410     Filename *ret;
 411
 412     bufsize = FILENAME_MAX;
 413     buffer = snewn(bufsize, char);
 414     buflen = 0;
 415     s = filename_to_str(src);
 416
 417     while (*s) {
 418         /* Let (bufp, len) be the string to append. */
 419         bufp = buf;                    /* don't usually override this */
 420         if (*s == '&') {
 421             char c;
 422             s++;
 423             size = 0;
 424             if (*s) switch (c = *s++, tolower((unsigned char)c)) {
 425               case 'y':
 426                 size = strftime(buf, sizeof(buf), "%Y", tm);
 427                 break;
 428               case 'm':
 429                 size = strftime(buf, sizeof(buf), "%m", tm);
 430                 break;
 431               case 'd':
 432                 size = strftime(buf, sizeof(buf), "%d", tm);
 433                 break;
 434               case 't':
 435                 size = strftime(buf, sizeof(buf), "%H%M%S", tm);
 436                 break;
 437               case 'h':
 438                 bufp = hostname;
 439                 size = strlen(bufp);
 440                 break;
 441               default:
 442                 buf[0] = '&';
 443                 size = 1;
 444                 if (c != '&')
 445                     buf[size++] = c;
 446             }
 447         } else {
 448             buf[0] = *s++;
 449             size = 1;
 450         }
 451         if (bufsize <= buflen + size) {
 452             bufsize = (buflen + size) * 5 / 4 + 512;
 453             buffer = sresize(buffer, bufsize, char);
 454         }
 455         memcpy(buffer + buflen, bufp, size);
 456         buflen += size;
 457     }
 458     buffer[buflen] = '\0';
 459
 460     ret = filename_from_str(buffer);
 461     sfree(buffer);
 462     return ret;
 463 }