+/*
+ * 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.
+ */
+
+char *dupstr(const char *s)
+{
+ char *p = NULL;
+ if (s) {
+ int len = strlen(s);
+ p = snewn(len + 1, char);
+ strcpy(p, s);
+ }
+ return p;
+}
+
+/* Allocate the concatenation of N strings. Terminate arg list with NULL. */
+char *dupcat(const char *s1, ...)
+{
+ int len;
+ char *p, *q, *sn;
+ va_list ap;
+
+ len = strlen(s1);
+ va_start(ap, s1);
+ while (1) {
+ sn = va_arg(ap, char *);
+ if (!sn)
+ break;
+ len += strlen(sn);
+ }
+ va_end(ap);
+
+ p = snewn(len + 1, char);
+ strcpy(p, s1);
+ q = p + strlen(p);
+
+ va_start(ap, s1);
+ while (1) {
+ sn = va_arg(ap, char *);
+ if (!sn)
+ break;
+ strcpy(q, sn);
+ q += strlen(q);
+ }
+ va_end(ap);
+
+ return p;
+}
+
+/*
+ * Do an sprintf(), but into a custom-allocated buffer.
+ *
+ * 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, ...)
+{
+ char *ret;
+ va_list ap;
+ va_start(ap, fmt);
+ ret = dupvprintf(fmt, ap);
+ va_end(ap);
+ return ret;
+}
+char *dupvprintf(const char *fmt, va_list ap)
+{
+ char *buf;
+ int len, size;
+
+ buf = snewn(512, char);
+ size = 512;
+
+ while (1) {
+#ifdef _WINDOWS
+#define vsnprintf _vsnprintf
+#endif
+ len = vsnprintf(buf, size, fmt, ap);
+ if (len >= 0 && len < size) {
+ /* This is the C99-specified criterion for snprintf to have
+ * been completely successful. */
+ return buf;
+ } else if (len > 0) {
+ /* This is the C99 error condition: the returned length is
+ * the required buffer size not counting the NUL. */
+ size = len + 1;
+ } else {
+ /* This is the pre-C99 glibc error condition: <0 means the
+ * buffer wasn't big enough, so we enlarge it a bit and hope. */
+ size += 512;
+ }
+ buf = sresize(buf, size, char);
+ }
+}
+
+/*
+ * 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.
+ */
+
+void base64_encode_atom(unsigned char *data, int n, char *out)
+{
+ static const char base64_chars[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+ unsigned word;
+
+ word = data[0] << 16;
+ if (n > 1)
+ word |= data[1] << 8;
+ if (n > 2)
+ word |= data[2];
+ out[0] = base64_chars[(word >> 18) & 0x3F];
+ out[1] = base64_chars[(word >> 12) & 0x3F];
+ if (n > 1)
+ out[2] = base64_chars[(word >> 6) & 0x3F];
+ else
+ out[2] = '=';
+ if (n > 2)
+ out[3] = base64_chars[word & 0x3F];
+ else
+ out[3] = '=';
+}
+
+/* ----------------------------------------------------------------------
+ * Generic routines to deal with send buffers: a linked list of
+ * smallish blocks, with the operations
+ *
+ * - add an arbitrary amount of data to the end of the list
+ * - remove the first N bytes from the list
+ * - return a (pointer,length) pair giving some initial data in
+ * the list, suitable for passing to a send or write system
+ * call
+ * - retrieve a larger amount of initial data from the list
+ * - return the current size of the buffer chain in bytes
+ */
+
+#define BUFFER_GRANULE 512
+
+struct bufchain_granule {
+ struct bufchain_granule *next;
+ int buflen, bufpos;
+ char buf[BUFFER_GRANULE];
+};
+
+void bufchain_init(bufchain *ch)
+{
+ ch->head = ch->tail = NULL;
+ ch->buffersize = 0;
+}
+
+void bufchain_clear(bufchain *ch)
+{
+ struct bufchain_granule *b;
+ while (ch->head) {
+ b = ch->head;
+ ch->head = ch->head->next;
+ sfree(b);
+ }
+ ch->tail = NULL;
+ ch->buffersize = 0;
+}
+
+int bufchain_size(bufchain *ch)
+{
+ return ch->buffersize;
+}
+
+void bufchain_add(bufchain *ch, const void *data, int len)
+{
+ const char *buf = (const char *)data;
+
+ if (len == 0) return;
+
+ ch->buffersize += len;
+
+ if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) {
+ int copylen = min(len, BUFFER_GRANULE - ch->tail->buflen);
+ memcpy(ch->tail->buf + ch->tail->buflen, buf, copylen);
+ buf += copylen;
+ len -= copylen;
+ ch->tail->buflen += copylen;
+ }
+ while (len > 0) {
+ int grainlen = min(len, BUFFER_GRANULE);
+ struct bufchain_granule *newbuf;
+ newbuf = snew(struct bufchain_granule);
+ newbuf->bufpos = 0;
+ newbuf->buflen = grainlen;
+ memcpy(newbuf->buf, buf, grainlen);
+ buf += grainlen;
+ len -= grainlen;
+ if (ch->tail)
+ ch->tail->next = newbuf;
+ else
+ ch->head = ch->tail = newbuf;
+ newbuf->next = NULL;
+ ch->tail = newbuf;
+ }
+}
+
+void bufchain_consume(bufchain *ch, int len)
+{
+ struct bufchain_granule *tmp;
+
+ assert(ch->buffersize >= len);
+ while (len > 0) {
+ int remlen = len;
+ assert(ch->head != NULL);
+ if (remlen >= ch->head->buflen - ch->head->bufpos) {
+ remlen = ch->head->buflen - ch->head->bufpos;
+ tmp = ch->head;
+ ch->head = tmp->next;
+ sfree(tmp);
+ if (!ch->head)
+ ch->tail = NULL;
+ } else
+ ch->head->bufpos += remlen;
+ ch->buffersize -= remlen;
+ len -= remlen;
+ }
+}
+
+void bufchain_prefix(bufchain *ch, void **data, int *len)
+{
+ *len = ch->head->buflen - ch->head->bufpos;
+ *data = ch->head->buf + ch->head->bufpos;
+}
+
+void bufchain_fetch(bufchain *ch, void *data, int len)
+{
+ struct bufchain_granule *tmp;
+ char *data_c = (char *)data;
+
+ tmp = ch->head;
+
+ assert(ch->buffersize >= len);
+ while (len > 0) {
+ int remlen = len;
+
+ assert(tmp != NULL);
+ if (remlen >= tmp->buflen - tmp->bufpos)
+ remlen = tmp->buflen - tmp->bufpos;
+ memcpy(data_c, tmp->buf + tmp->bufpos, remlen);
+
+ tmp = tmp->next;
+ len -= remlen;
+ data_c += remlen;
+ }
+}
+
+/* ----------------------------------------------------------------------
+ * My own versions of malloc, realloc and free. Because I want
+ * malloc and realloc to bomb out and exit the program if they run
+ * out of memory, realloc to reliably call malloc if passed a NULL
+ * pointer, and free to reliably do nothing if passed a NULL
+ * pointer. We can also put trace printouts in, if we need to; and
+ * we can also replace the allocator with an ElectricFence-like
+ * one.
+ */
+
+#ifdef MINEFIELD
+void *minefield_c_malloc(size_t size);
+void minefield_c_free(void *p);
+void *minefield_c_realloc(void *p, size_t size);
+#endif