diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/lwip/lwip/src/apps/tftp/tftp.c | 54 |
1 files changed, 45 insertions, 9 deletions
diff --git a/lib/lwip/lwip/src/apps/tftp/tftp.c b/lib/lwip/lwip/src/apps/tftp/tftp.c index 56aeabc4d73..63b1e0e0e20 100644 --- a/lib/lwip/lwip/src/apps/tftp/tftp.c +++ b/lib/lwip/lwip/src/apps/tftp/tftp.c @@ -264,19 +264,55 @@ static u16_t payload_size(void) return TFTP_DEFAULT_BLOCK_SIZE; } +/** + * find_option() - check if OACK message contains option + * + * @p: message buffer + * @option: option key + * Return: option value + */ static const char * find_option(struct pbuf *p, const char *option) { - int i; - u16_t optlen = strlen(option); - const char *b = p->payload; - - for (i = 0; i + optlen + 1 < p->len; i++) { - if (lwip_strnstr(b + i, option, optlen)) - return b + i + optlen + 2; - } + const char *pos = p->payload; + int rem = p->len; + + /* + * According to RFC 2347 the OACK packet has the following format: + * + * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ + * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 | + * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ + */ + + /* Skip opc */ + pos += 2; + rem -= 2; + if (rem <= 0) + return NULL; + + for (;;) { + int len; + int diff; + + len = strnlen(pos, rem) + 1; + if (rem < len) + break; + diff = strcmp(pos, option); + /* Skip option */ + pos += len; + rem -= len; + len = strnlen(pos, rem) + 1; + if (rem < len) + break; + if (!diff) + return pos; + /* Skip value */ + pos += len; + rem -= len; + } - return NULL; + return NULL; } static void |