#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <limits.h>
#include <ctype.h>
#include <assert.h>
#include "putty.h"
+/*
+ * Parse a string block size specification. This is approximately a
+ * subset of the block size specs supported by GNU fileutils:
+ * "nk" = n kilobytes
+ * "nM" = n megabytes
+ * "nG" = n gigabytes
+ * All numbers are decimal, and suffixes refer to powers of two.
+ * Case-insensitive.
+ */
+unsigned long parse_blocksize(const char *bs)
+{
+ char *suf;
+ unsigned long r = strtoul(bs, &suf, 10);
+ if (*suf != '\0') {
+ while (isspace(*suf)) suf++;
+ switch (*suf) {
+ case 'k': case 'K':
+ r *= 1024ul;
+ break;
+ case 'm': case 'M':
+ r *= 1024ul * 1024ul;
+ break;
+ case 'g': case 'G':
+ r *= 1024ul * 1024ul * 1024ul;
+ break;
+ case '\0':
+ default:
+ break;
+ }
+ }
+ return r;
+}
+
/* ----------------------------------------------------------------------
* String handling routines.
*/
/*
* Do an sprintf(), but into a custom-allocated buffer.
*
- * Irritatingly, we don't seem to be able to do this portably using
- * vsnprintf(), because there appear to be issues with re-using the
- * same va_list for two calls, and the excellent C99 va_copy is not
- * yet widespread. Bah. Instead I'm going to do a horrid, horrid
- * hack, in which I trawl the format string myself, work out the
- * maximum length of each format component, and resize the buffer
- * before printing it.
+ * Currently I'm doing this via vsnprintf. This has worked so far,
+ * but it's not good, because:
+ *
+ * - vsnprintf is not available on all platforms. There's an ifdef
+ * to use `_vsnprintf', which seems to be the local name for it
+ * on Windows. Other platforms may lack it completely, in which
+ * case it'll be time to rewrite this function in a totally
+ * different way.
+ *
+ * - technically you can't reuse a va_list like this: it is left
+ * unspecified whether advancing a va_list pointer modifies its
+ * value or something it points to, so on some platforms calling
+ * vsnprintf twice on the same va_list might fail hideously. It
+ * would be better to use the `va_copy' macro mandated by C99,
+ * but that too is not yet ubiquitous.
+ *
+ * The only `properly' portable solution I can think of is to
+ * implement my own format string scanner, which figures out an
+ * upper bound for the length of each formatting directive,
+ * allocates the buffer as it goes along, and calls sprintf() to
+ * actually process each directive. If I ever need to actually do
+ * this, some caveats:
+ *
+ * - It's very hard to find a reliable upper bound for
+ * floating-point values. %f, in particular, when supplied with
+ * a number near to the upper or lower limit of representable
+ * numbers, could easily take several hundred characters. It's
+ * probably feasible to predict this statically using the
+ * constants in <float.h>, or even to predict it dynamically by
+ * looking at the exponent of the specific float provided, but
+ * it won't be fun.
+ *
+ * - Don't forget to _check_, after calling sprintf, that it's
+ * used at most the amount of space we had available.
+ *
+ * - Fault any formatting directive we don't fully understand. The
+ * aim here is to _guarantee_ that we never overflow the buffer,
+ * because this is a security-critical function. If we see a
+ * directive we don't know about, we should panic and die rather
+ * than run any risk.
*/
char *dupprintf(const char *fmt, ...)
{
}
}
+/*
+ * Read an entire line of text from a file. Return a buffer
+ * malloced to be as big as necessary (caller must free).
+ */
+char *fgetline(FILE *fp)
+{
+ char *ret = snewn(512, char);
+ int size = 512, len = 0;
+ while (fgets(ret + len, size - len, fp)) {
+ len += strlen(ret + len);
+ if (ret[len-1] == '\n')
+ break; /* got a newline, we're done */
+ size = len + 512;
+ ret = sresize(ret, size, char);
+ }
+ if (len == 0) { /* first fgets returned NULL */
+ sfree(ret);
+ return NULL;
+ }
+ ret[len] = '\0';
+ return ret;
+}
+
/* ----------------------------------------------------------------------
* Base64 encoding routine. This is required in public-key writing
* but also in HTTP proxy handling, so it's centralised here.
}
#endif
-void *safemalloc(size_t size)
+void *safemalloc(size_t n, size_t size)
{
void *p;
+
+ if (n > INT_MAX / size) {
+ p = NULL;
+ } else {
+ size *= n;
#ifdef MINEFIELD
- p = minefield_c_malloc(size);
+ p = minefield_c_malloc(size);
#else
- p = malloc(size);
+ p = malloc(size);
#endif
+ }
+
if (!p) {
char str[200];
#ifdef MALLOC_LOG
return p;
}
-void *saferealloc(void *ptr, size_t size)
+void *saferealloc(void *ptr, size_t n, size_t size)
{
void *p;
- if (!ptr) {
+
+ if (n > INT_MAX / size) {
+ p = NULL;
+ } else {
+ size *= n;
+ if (!ptr) {
#ifdef MINEFIELD
- p = minefield_c_malloc(size);
+ p = minefield_c_malloc(size);
#else
- p = malloc(size);
+ p = malloc(size);
#endif
- } else {
+ } else {
#ifdef MINEFIELD
- p = minefield_c_realloc(ptr, size);
+ p = minefield_c_realloc(ptr, size);
#else
- p = realloc(ptr, size);
+ p = realloc(ptr, size);
#endif
+ }
}
+
if (!p) {
char str[200];
#ifdef MALLOC_LOG