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