2 * Platform-independent routines shared between all PuTTY programs.
12 /* ----------------------------------------------------------------------
13 * String handling routines.
16 char *dupstr(const char *s)
21 p = snewn(len + 1, char);
27 /* Allocate the concatenation of N strings. Terminate arg list with NULL. */
28 char *dupcat(const char *s1, ...)
37 sn = va_arg(ap, char *);
44 p = snewn(len + 1, char);
50 sn = va_arg(ap, char *);
62 * Do an sprintf(), but into a custom-allocated buffer.
64 * Currently I'm doing this via vsnprintf. This has worked so far,
65 * but it's not good, because:
67 * - vsnprintf is not available on all platforms. There's an ifdef
68 * to use `_vsnprintf', which seems to be the local name for it
69 * on Windows. Other platforms may lack it completely, in which
70 * case it'll be time to rewrite this function in a totally
73 * - technically you can't reuse a va_list like this: it is left
74 * unspecified whether advancing a va_list pointer modifies its
75 * value or something it points to, so on some platforms calling
76 * vsnprintf twice on the same va_list might fail hideously. It
77 * would be better to use the `va_copy' macro mandated by C99,
78 * but that too is not yet ubiquitous.
80 * The only `properly' portable solution I can think of is to
81 * implement my own format string scanner, which figures out an
82 * upper bound for the length of each formatting directive,
83 * allocates the buffer as it goes along, and calls sprintf() to
84 * actually process each directive. If I ever need to actually do
87 * - It's very hard to find a reliable upper bound for
88 * floating-point values. %f, in particular, when supplied with
89 * a number near to the upper or lower limit of representable
90 * numbers, could easily take several hundred characters. It's
91 * probably feasible to predict this statically using the
92 * constants in <float.h>, or even to predict it dynamically by
93 * looking at the exponent of the specific float provided, but
96 * - Don't forget to _check_, after calling sprintf, that it's
97 * used at most the amount of space we had available.
99 * - Fault any formatting directive we don't fully understand. The
100 * aim here is to _guarantee_ that we never overflow the buffer,
101 * because this is a security-critical function. If we see a
102 * directive we don't know about, we should panic and die rather
105 char *dupprintf(const char *fmt, ...)
110 ret = dupvprintf(fmt, ap);
114 char *dupvprintf(const char *fmt, va_list ap)
119 buf = snewn(512, char);
124 #define vsnprintf _vsnprintf
126 len = vsnprintf(buf, size, fmt, ap);
127 if (len >= 0 && len < size) {
128 /* This is the C99-specified criterion for snprintf to have
129 * been completely successful. */
131 } else if (len > 0) {
132 /* This is the C99 error condition: the returned length is
133 * the required buffer size not counting the NUL. */
136 /* This is the pre-C99 glibc error condition: <0 means the
137 * buffer wasn't big enough, so we enlarge it a bit and hope. */
140 buf = sresize(buf, size, char);
145 * Read an entire line of text from a file. Return a buffer
146 * malloced to be as big as necessary (caller must free).
148 char *fgetline(FILE *fp)
150 char *ret = snewn(512, char);
151 int size = 512, len = 0;
152 while (fgets(ret + len, size - len, fp)) {
153 len += strlen(ret + len);
154 if (ret[len-1] == '\n')
155 break; /* got a newline, we're done */
157 ret = sresize(ret, size, char);
159 if (len == 0) { /* first fgets returned NULL */
167 /* ----------------------------------------------------------------------
168 * Base64 encoding routine. This is required in public-key writing
169 * but also in HTTP proxy handling, so it's centralised here.
172 void base64_encode_atom(unsigned char *data, int n, char *out)
174 static const char base64_chars[] =
175 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
179 word = data[0] << 16;
181 word |= data[1] << 8;
184 out[0] = base64_chars[(word >> 18) & 0x3F];
185 out[1] = base64_chars[(word >> 12) & 0x3F];
187 out[2] = base64_chars[(word >> 6) & 0x3F];
191 out[3] = base64_chars[word & 0x3F];
196 /* ----------------------------------------------------------------------
197 * Generic routines to deal with send buffers: a linked list of
198 * smallish blocks, with the operations
200 * - add an arbitrary amount of data to the end of the list
201 * - remove the first N bytes from the list
202 * - return a (pointer,length) pair giving some initial data in
203 * the list, suitable for passing to a send or write system
205 * - retrieve a larger amount of initial data from the list
206 * - return the current size of the buffer chain in bytes
209 #define BUFFER_GRANULE 512
211 struct bufchain_granule {
212 struct bufchain_granule *next;
214 char buf[BUFFER_GRANULE];
217 void bufchain_init(bufchain *ch)
219 ch->head = ch->tail = NULL;
223 void bufchain_clear(bufchain *ch)
225 struct bufchain_granule *b;
228 ch->head = ch->head->next;
235 int bufchain_size(bufchain *ch)
237 return ch->buffersize;
240 void bufchain_add(bufchain *ch, const void *data, int len)
242 const char *buf = (const char *)data;
244 if (len == 0) return;
246 ch->buffersize += len;
248 if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) {
249 int copylen = min(len, BUFFER_GRANULE - ch->tail->buflen);
250 memcpy(ch->tail->buf + ch->tail->buflen, buf, copylen);
253 ch->tail->buflen += copylen;
256 int grainlen = min(len, BUFFER_GRANULE);
257 struct bufchain_granule *newbuf;
258 newbuf = snew(struct bufchain_granule);
260 newbuf->buflen = grainlen;
261 memcpy(newbuf->buf, buf, grainlen);
265 ch->tail->next = newbuf;
267 ch->head = ch->tail = newbuf;
273 void bufchain_consume(bufchain *ch, int len)
275 struct bufchain_granule *tmp;
277 assert(ch->buffersize >= len);
280 assert(ch->head != NULL);
281 if (remlen >= ch->head->buflen - ch->head->bufpos) {
282 remlen = ch->head->buflen - ch->head->bufpos;
284 ch->head = tmp->next;
289 ch->head->bufpos += remlen;
290 ch->buffersize -= remlen;
295 void bufchain_prefix(bufchain *ch, void **data, int *len)
297 *len = ch->head->buflen - ch->head->bufpos;
298 *data = ch->head->buf + ch->head->bufpos;
301 void bufchain_fetch(bufchain *ch, void *data, int len)
303 struct bufchain_granule *tmp;
304 char *data_c = (char *)data;
308 assert(ch->buffersize >= len);
313 if (remlen >= tmp->buflen - tmp->bufpos)
314 remlen = tmp->buflen - tmp->bufpos;
315 memcpy(data_c, tmp->buf + tmp->bufpos, remlen);
323 /* ----------------------------------------------------------------------
324 * My own versions of malloc, realloc and free. Because I want
325 * malloc and realloc to bomb out and exit the program if they run
326 * out of memory, realloc to reliably call malloc if passed a NULL
327 * pointer, and free to reliably do nothing if passed a NULL
328 * pointer. We can also put trace printouts in, if we need to; and
329 * we can also replace the allocator with an ElectricFence-like
334 void *minefield_c_malloc(size_t size);
335 void minefield_c_free(void *p);
336 void *minefield_c_realloc(void *p, size_t size);
340 static FILE *fp = NULL;
342 static char *mlog_file = NULL;
343 static int mlog_line = 0;
345 void mlog(char *file, int line)
350 fp = fopen("putty_mem.log", "w");
351 setvbuf(fp, NULL, _IONBF, BUFSIZ);
354 fprintf(fp, "%s:%d: ", file, line);
358 void *safemalloc(size_t size)
362 p = minefield_c_malloc(size);
369 sprintf(str, "Out of memory! (%s:%d, size=%d)",
370 mlog_file, mlog_line, size);
371 fprintf(fp, "*** %s\n", str);
374 strcpy(str, "Out of memory!");
380 fprintf(fp, "malloc(%d) returns %p\n", size, p);
385 void *saferealloc(void *ptr, size_t size)
390 p = minefield_c_malloc(size);
396 p = minefield_c_realloc(ptr, size);
398 p = realloc(ptr, size);
404 sprintf(str, "Out of memory! (%s:%d, size=%d)",
405 mlog_file, mlog_line, size);
406 fprintf(fp, "*** %s\n", str);
409 strcpy(str, "Out of memory!");
415 fprintf(fp, "realloc(%p,%d) returns %p\n", ptr, size, p);
420 void safefree(void *ptr)
425 fprintf(fp, "free(%p)\n", ptr);
428 minefield_c_free(ptr);
435 fprintf(fp, "freeing null pointer - no action taken\n");
439 /* ----------------------------------------------------------------------
440 * Debugging routines.
444 extern void dputs(char *); /* defined in per-platform *misc.c */
446 void debug_printf(char *fmt, ...)
452 buf = dupvprintf(fmt, ap);
459 void debug_memdump(void *buf, int len, int L)
462 unsigned char *p = buf;
466 debug_printf("\t%d (0x%x) bytes:\n", len, len);
467 delta = 15 & (int) p;
471 for (; 0 < len; p += 16, len -= 16) {
474 debug_printf("%p: ", p);
475 strcpy(foo, "................"); /* sixteen dots */
476 for (i = 0; i < 16 && i < len; ++i) {
477 if (&p[i] < (unsigned char *) buf) {
478 dputs(" "); /* 3 spaces */
481 debug_printf("%c%02.2x",
482 &p[i] != (unsigned char *) buf
483 && i % 4 ? '.' : ' ', p[i]
485 if (p[i] >= ' ' && p[i] <= '~')
486 foo[i] = (char) p[i];
490 debug_printf("%*s%s\n", (16 - i) * 3 + 2, "", foo);
494 #endif /* def DEBUG */