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 void xlatlognam(Filename *d, 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     xlatlognam(&ctx->currlogfilename,
 159                *conf_get_filename(ctx->conf, CONF_logfilename),
 160                conf_get_str(ctx->conf, CONF_host), &tm);
 161
 162     ctx->lgfp = f_open(ctx->currlogfilename, "r", FALSE);  /* file already present? */
 163     if (ctx->lgfp) {
 164         int logxfovr = conf_get_int(ctx->conf, CONF_logxfovr);
 165         fclose(ctx->lgfp);
 166         if (logxfovr != LGXF_ASK) {
 167             mode = ((logxfovr == LGXF_OVR) ? 2 : 1);
 168         } else
 169             mode = askappend(ctx->frontend, ctx->currlogfilename,
 170                              logfopen_callback, ctx);
 171     } else
 172         mode = 2;                      /* create == overwrite */
 173
 174     if (mode < 0)
 175         ctx->state = L_OPENING;
 176     else
 177         logfopen_callback(ctx, mode);  /* open the file */
 178 }
 179
 180 void logfclose(void *handle)
 181 {
 182     struct LogContext *ctx = (struct LogContext *)handle;
 183     if (ctx->lgfp) {
 184         fclose(ctx->lgfp);
 185         ctx->lgfp = NULL;
 186     }
 187     ctx->state = L_CLOSED;
 188 }
 189
 190 /*
 191  * Log session traffic.
 192  */
 193 void logtraffic(void *handle, unsigned char c, int logmode)
 194 {
 195     struct LogContext *ctx = (struct LogContext *)handle;
 196     if (ctx->logtype > 0) {
 197         if (ctx->logtype == logmode)
 198             logwrite(ctx, &c, 1);
 199     }
 200 }
 201
 202 /*
 203  * Log an Event Log entry. Used in SSH packet logging mode; this is
 204  * also as convenient a place as any to put the output of Event Log
 205  * entries to stderr when a command-line tool is in verbose mode.
 206  * (In particular, this is a better place to put it than in the
 207  * front ends, because it only has to be done once for all
 208  * platforms. Platforms which don't have a meaningful stderr can
 209  * just avoid defining FLAG_STDERR.
 210  */
 211 void log_eventlog(void *handle, const char *event)
 212 {
 213     struct LogContext *ctx = (struct LogContext *)handle;
 214     if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) {
 215         fprintf(stderr, "%s\n", event);
 216         fflush(stderr);
 217     }
 218     /* If we don't have a context yet (eg winnet.c init) then skip entirely */
 219     if (!ctx)
 220         return;
 221     if (ctx->logtype != LGTYP_PACKETS &&
 222         ctx->logtype != LGTYP_SSHRAW)
 223         return;
 224     logprintf(ctx, "Event Log: %s\r\n", event);
 225     logflush(ctx);
 226 }
 227
 228 /*
 229  * Log an SSH packet.
 230  * If n_blanks != 0, blank or omit some parts.
 231  * Set of blanking areas must be in increasing order.
 232  */
 233 void log_packet(void *handle, int direction, int type,
 234                 char *texttype, const void *data, int len,
 235                 int n_blanks, const struct logblank_t *blanks,
 236                 const unsigned long *seq)
 237 {
 238     struct LogContext *ctx = (struct LogContext *)handle;
 239     char dumpdata[80], smalldata[5];
 240     int p = 0, b = 0, omitted = 0;
 241     int output_pos = 0; /* NZ if pending output in dumpdata */
 242
 243     if (!(ctx->logtype == LGTYP_SSHRAW ||
 244           (ctx->logtype == LGTYP_PACKETS && texttype)))
 245         return;
 246
 247     /* Packet header. */
 248     if (texttype) {
 249         if (seq) {
 250             logprintf(ctx, "%s packet #0x%lx, type %d / 0x%02x (%s)\r\n",
 251                       direction == PKT_INCOMING ? "Incoming" : "Outgoing",
 252                       *seq, type, type, texttype);
 253         } else {
 254             logprintf(ctx, "%s packet type %d / 0x%02x (%s)\r\n",
 255                       direction == PKT_INCOMING ? "Incoming" : "Outgoing",
 256                       type, type, texttype);
 257         }
 258     } else {
 259         logprintf(ctx, "%s raw data\r\n",
 260                   direction == PKT_INCOMING ? "Incoming" : "Outgoing");
 261     }
 262
 263     /*
 264      * Output a hex/ASCII dump of the packet body, blanking/omitting
 265      * parts as specified.
 266      */
 267     while (p < len) {
 268         int blktype;
 269
 270         /* Move to a current entry in the blanking array. */
 271         while ((b < n_blanks) &&
 272                (p >= blanks[b].offset + blanks[b].len))
 273             b++;
 274         /* Work out what type of blanking to apply to
 275          * this byte. */
 276         blktype = PKTLOG_EMIT; /* default */
 277         if ((b < n_blanks) &&
 278             (p >= blanks[b].offset) &&
 279             (p < blanks[b].offset + blanks[b].len))
 280             blktype = blanks[b].type;
 281
 282         /* If we're about to stop omitting, it's time to say how
 283          * much we omitted. */
 284         if ((blktype != PKTLOG_OMIT) && omitted) {
 285             logprintf(ctx, "  (%d byte%s omitted)\r\n",
 286                       omitted, (omitted==1?"":"s"));
 287             omitted = 0;
 288         }
 289
 290         /* (Re-)initialise dumpdata as necessary
 291          * (start of row, or if we've just stopped omitting) */
 292         if (!output_pos && !omitted)
 293             sprintf(dumpdata, "  %08x%*s\r\n", p-(p%16), 1+3*16+2+16, "");
 294
 295         /* Deal with the current byte. */
 296         if (blktype == PKTLOG_OMIT) {
 297             omitted++;
 298         } else {
 299             int c;
 300             if (blktype == PKTLOG_BLANK) {
 301                 c = 'X';
 302                 sprintf(smalldata, "XX");
 303             } else {  /* PKTLOG_EMIT */
 304                 c = ((unsigned char *)data)[p];
 305                 sprintf(smalldata, "%02x", c);
 306             }
 307             dumpdata[10+2+3*(p%16)] = smalldata[0];
 308             dumpdata[10+2+3*(p%16)+1] = smalldata[1];
 309             dumpdata[10+1+3*16+2+(p%16)] = (isprint(c) ? c : '.');
 310             output_pos = (p%16) + 1;
 311         }
 312
 313         p++;
 314
 315         /* Flush row if necessary */
 316         if (((p % 16) == 0) || (p == len) || omitted) {
 317             if (output_pos) {
 318                 strcpy(dumpdata + 10+1+3*16+2+output_pos, "\r\n");
 319                 logwrite(ctx, dumpdata, strlen(dumpdata));
 320                 output_pos = 0;
 321             }
 322         }
 323
 324     }
 325
 326     /* Tidy up */
 327     if (omitted)
 328         logprintf(ctx, "  (%d byte%s omitted)\r\n",
 329                   omitted, (omitted==1?"":"s"));
 330     logflush(ctx);
 331 }
 332
 333 void *log_init(void *frontend, Conf *conf)
 334 {
 335     struct LogContext *ctx = snew(struct LogContext);
 336     ctx->lgfp = NULL;
 337     ctx->state = L_CLOSED;
 338     ctx->frontend = frontend;
 339     ctx->conf = conf_copy(conf);
 340     ctx->logtype = conf_get_int(ctx->conf, CONF_logtype);
 341     bufchain_init(&ctx->queue);
 342     return ctx;
 343 }
 344
 345 void log_free(void *handle)
 346 {
 347     struct LogContext *ctx = (struct LogContext *)handle;
 348
 349     logfclose(ctx);
 350     bufchain_clear(&ctx->queue);
 351     sfree(ctx);
 352 }
 353
 354 void log_reconfig(void *handle, Conf *conf)
 355 {
 356     struct LogContext *ctx = (struct LogContext *)handle;
 357     int reset_logging;
 358
 359     if (!filename_equal(*conf_get_filename(ctx->conf, CONF_logfilename),
 360                         *conf_get_filename(conf, CONF_logfilename)) ||
 361         conf_get_int(ctx->conf, CONF_logtype) !=
 362         conf_get_int(conf, CONF_logtype))
 363         reset_logging = TRUE;
 364     else
 365         reset_logging = FALSE;
 366
 367     if (reset_logging)
 368         logfclose(ctx);
 369
 370     conf_free(ctx->conf);
 371     ctx->conf = conf_copy(conf);
 372
 373     ctx->logtype = conf_get_int(ctx->conf, CONF_logtype);
 374
 375     if (reset_logging)
 376         logfopen(ctx);
 377 }
 378
 379 /*
 380  * translate format codes into time/date strings
 381  * and insert them into log file name
 382  *
 383  * "&Y":YYYY   "&m":MM   "&d":DD   "&T":hhmmss   "&h":<hostname>   "&&":&
 384  */
 385 static void xlatlognam(Filename *dest, Filename src,
 386                        char *hostname, struct tm *tm) {
 387     char buf[10], *bufp;
 388     int size;
 389     char buffer[FILENAME_MAX];
 390     int len = sizeof(buffer)-1;
 391     char *d;
 392     const char *s;
 393
 394     d = buffer;
 395     s = filename_to_str(&src);
 396
 397     while (*s) {
 398         /* Let (bufp, len) be the string to append. */
 399         bufp = buf;                    /* don't usually override this */
 400         if (*s == '&') {
 401             char c;
 402             s++;
 403             size = 0;
 404             if (*s) switch (c = *s++, tolower((unsigned char)c)) {
 405               case 'y':
 406                 size = strftime(buf, sizeof(buf), "%Y", tm);
 407                 break;
 408               case 'm':
 409                 size = strftime(buf, sizeof(buf), "%m", tm);
 410                 break;
 411               case 'd':
 412                 size = strftime(buf, sizeof(buf), "%d", tm);
 413                 break;
 414               case 't':
 415                 size = strftime(buf, sizeof(buf), "%H%M%S", tm);
 416                 break;
 417               case 'h':
 418                 bufp = hostname;
 419                 size = strlen(bufp);
 420                 break;
 421               default:
 422                 buf[0] = '&';
 423                 size = 1;
 424                 if (c != '&')
 425                     buf[size++] = c;
 426             }
 427         } else {
 428             buf[0] = *s++;
 429             size = 1;
 430         }
 431         if (size > len)
 432             size = len;
 433         memcpy(d, bufp, size);
 434         d += size;
 435         len -= size;
 436     }
 437     *d = '\0';
 438
 439     *dest = filename_from_str(buffer);
 440 }