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