*
* @param[in] dbuff buffer containing the option
* @param[in] hdr marker (with dbuff as parent) set to where the option starts
- * @param[in] len length of the data being written
+ * @param[in] len length of the data being written
* @return
- * - false if we can't extend the option
- * - true if we can, with hdr set to where the next option should start
+ * - <0 if we can't extend the option
+ * - >0 if we can, with hdr set to where the next option should start
* @note The option starts with a two-byte (type, length) header, where
* the length does *not* include the two bytes for the header.
* The starting length may be non-zero, hence its counting towards
* (All those following start out empty, hence the initialization
* of their lengths to zero.)
*/
-static bool extend_option(fr_dbuff_t *dbuff, fr_dbuff_marker_t *hdr, int len)
+static ssize_t extend_option(fr_dbuff_t *dbuff, fr_dbuff_marker_t *hdr, size_t len)
{
- size_t header_bytes;
+ size_t header_bytes;
uint8_t type = 0, option_len = 0;
- fr_dbuff_marker_t src, dest, hdr_io;
+ fr_dbuff_marker_t dst, tmp;
/*
* This can't follow the convention of operating on
* already-written data.
*/
- fr_dbuff_marker(&src, dbuff);
- fr_dbuff_marker(&dest, dbuff);
- fr_dbuff_marker(&hdr_io, dbuff);
+ fr_dbuff_marker(&dst, dbuff);
+ fr_dbuff_marker(&tmp, dbuff);
- fr_dbuff_set(&hdr_io, hdr);
- if (fr_dbuff_out(&type, &hdr_io) < 0 || fr_dbuff_out(&option_len, &hdr_io) < 0) {
+ fr_dbuff_set(&tmp, hdr);
+
+ /*
+ * Read the current header.
+ */
+ if (fr_dbuff_out(&type, &tmp) < 0 || fr_dbuff_out(&option_len, &tmp) < 0) {
error:
- fr_dbuff_marker_release(&dest);
- fr_dbuff_marker_release(&src);
- fr_dbuff_marker_release(&hdr_io);
- return false;
+ fr_dbuff_marker_release(&dst);
+ fr_dbuff_marker_release(&tmp);
+ return -1;
}
+ len += option_len;
+
/*
- * How many bytes we will need to add for headers.
+ * How many bytes we will need to add for all headers.
*/
- header_bytes = ((option_len + len) / 255) * 2;
+ header_bytes = (option_len / 255) * 2;
/*
* No room for the new headers and data, we're done.
*/
if (fr_dbuff_extend_lowat(NULL, dbuff, header_bytes) < header_bytes) goto error;
- fr_dbuff_advance(dbuff, header_bytes);
/*
* Moving the same data repeatedly in a loop is simpler
* and less error-prone than anything smarter.
*/
- while (len > 0) {
- int sublen;
+ while (true) {
+ uint8_t sublen;
- /*
- * Figure out how much data goes into this
- * option, and how much data we have to move out
- * of the way.
- */
- sublen = 255 - option_len;
- if (sublen > len) sublen = len;
+ sublen = (len > 255) ? 255 : len;
/*
- * Add in the data left at the current pointer.
+ * Write the new header, including the (possibly partial) length.
*/
- option_len += sublen;
- len -= sublen;
- fr_dbuff_set(&hdr_io, fr_dbuff_current(hdr) + 1);
- fr_dbuff_in(&hdr_io, option_len);
+ fr_dbuff_set(&tmp, fr_dbuff_current(hdr));
+ fr_dbuff_in_bytes(&tmp, type, sublen);
/*
- * Nothing more to do? Exit.
+ * The data is already where it's supposed to be, and the length is in the header, and
+ * the length is small. We're done.
*/
- if (!len) break;
+ len -= sublen;
+ if (!len) {
+ fr_dbuff_set(dbuff, fr_dbuff_current(hdr) + sublen + 2);
+ len = sublen;
+ break;
+ }
/*
- * The current option is full. So move the
- * trailing data up by 2 bytes, making room
- * for a new header.
+ * Take the current header, skip it, and then skip the data we just encoded. That is the
+ * location of the "next" header.
*/
- fr_dbuff_advance(hdr, option_len + 2);
- fr_dbuff_set(&src, hdr);
- fr_dbuff_set(&dest, fr_dbuff_current(hdr) + 2);
- fr_dbuff_move(&dest, &src, len);
+ fr_dbuff_set(&tmp, fr_dbuff_current(hdr) + 2 + 255);
+ fr_dbuff_set(hdr, &tmp);
/*
- * Initialize the new header.
+ * The data is currently overlapping with the next header. We have to move it two bytes forward to
+ * make room for the header.
*/
- option_len = 0;
- fr_dbuff_set(&hdr_io, hdr);
- fr_dbuff_in_bytes(&hdr_io, type, option_len);
+ fr_dbuff_set(&dst, fr_dbuff_current(&tmp) + 2);
+ fr_dbuff_move(&dst, &tmp, len);
}
- fr_dbuff_marker_release(&dest);
- fr_dbuff_marker_release(&src);
- fr_dbuff_marker_release(&hdr_io);
- return true;
+ fr_dbuff_marker_release(&dst);
+ fr_dbuff_marker_release(&tmp);
+ return len;
}
#define DHCPV4_OPT_HDR_LEN (2)
fr_dbuff_advance(&hdr, 1);
fr_dbuff_in(&hdr, (uint8_t) len);
- } else if (!extend_option(&work_dbuff, &hdr, len)) {
+ } else if (extend_option(&work_dbuff, &hdr, len) < 0) {
return PAIR_ENCODE_FATAL_ERROR;
}
if (len < 0) return len;
if (len == 0) break; /* Insufficient space */
- option_len += len;
-
/*
* If the newly added data fits within the current option, then
* update the header, and go to the next option.
*/
- if (option_len <= 255) {
- fr_dbuff_set(&tmp, fr_dbuff_current(&hdr) + 1);
- fr_dbuff_in_bytes(&tmp, (uint8_t) option_len);
-
- } else {
- next_hdr:
- option_len -= 255;
+ if ((option_len + len) <= 255) {
+ option_len += len;
- /*
- * Ensure that we have room for another TLV header.
- */
- if (fr_dbuff_extend_lowat(NULL, &work_dbuff, 2) < 2) break;
- fr_dbuff_advance(&work_dbuff, 2);
-
- /*
- * The first TLV is length 255
- */
fr_dbuff_set(&tmp, fr_dbuff_current(&hdr) + 1);
- fr_dbuff_in_bytes(&tmp, 255);
-
- /*
- * Point to where the next header should be
- */
- fr_dbuff_set(&tmp, fr_dbuff_current(&hdr) + 255 + 2);
- fr_dbuff_set(&hdr, &tmp);
+ fr_dbuff_in_bytes(&tmp, (uint8_t) option_len);
- /*
- * Move the encoded data 2 bytes forward
- * to account for the new header.
- */
- fr_dbuff_set(&dst, fr_dbuff_current(&tmp) + 2);
- fr_dbuff_move(&dst, &tmp, option_len);
+ } else if ((len = extend_option(&work_dbuff, &hdr, len)) < 0) {
+ return PAIR_ENCODE_FATAL_ERROR;
- /*
- * Update the header length
- */
- fr_dbuff_set(&tmp, &hdr);
- if (option_len < 255) {
- fr_dbuff_in_bytes(&tmp, option_number, (uint8_t) option_len);
- } else {
- fr_dbuff_in_bytes(&tmp, option_number, 0);
- goto next_hdr;
- }
+ } else {
+ option_len = len;
}
FR_PROTO_STACK_PRINT(da_stack, depth);
projects / thirdparty / freeradius-server.git / commitdiff
