diff options
Diffstat (limited to 'ares_parse_txt_reply.c')
| -rw-r--r-- | ares_parse_txt_reply.c | 133 |
1 files changed, 76 insertions, 57 deletions
diff --git a/ares_parse_txt_reply.c b/ares_parse_txt_reply.c index 5165332..4856b4c 100644 --- a/ares_parse_txt_reply.c +++ b/ares_parse_txt_reply.c @@ -17,9 +17,6 @@ #include "ares_setup.h" -#ifdef HAVE_SYS_SOCKET_H -# include <sys/socket.h> -#endif #ifdef HAVE_NETINET_IN_H # include <netinet/in.h> #endif @@ -42,28 +39,25 @@ # include <strings.h> #endif -#include <stdlib.h> -#include <string.h> - #include "ares.h" #include "ares_dns.h" #include "ares_data.h" #include "ares_private.h" -int -ares_parse_txt_reply (const unsigned char *abuf, int alen, - struct ares_txt_reply **txt_out) +static int +ares__parse_txt_reply (const unsigned char *abuf, int alen, + int ex, void **txt_out) { - size_t substr_len, str_len; + size_t substr_len; unsigned int qdcount, ancount, i; const unsigned char *aptr; const unsigned char *strptr; int status, rr_type, rr_class, rr_len; long len; char *hostname = NULL, *rr_name = NULL; - struct ares_txt_reply *txt_head = NULL; - struct ares_txt_reply *txt_last = NULL; - struct ares_txt_reply *txt_curr; + struct ares_txt_ext *txt_head = NULL; + struct ares_txt_ext *txt_last = NULL; + struct ares_txt_ext *txt_curr; /* Set *txt_out to NULL for all failure cases. */ *txt_out = NULL; @@ -88,7 +82,7 @@ ares_parse_txt_reply (const unsigned char *abuf, int alen, if (aptr + len + QFIXEDSZ > abuf + alen) { - free (hostname); + ares_free (hostname); return ARES_EBADRESP; } aptr += len + QFIXEDSZ; @@ -112,27 +106,15 @@ ares_parse_txt_reply (const unsigned char *abuf, int alen, rr_class = DNS_RR_CLASS (aptr); rr_len = DNS_RR_LEN (aptr); aptr += RRFIXEDSZ; + if (aptr + rr_len > abuf + alen) + { + status = ARES_EBADRESP; + break; + } /* Check if we are really looking at a TXT record */ if (rr_class == C_IN && rr_type == T_TXT) { - /* Allocate storage for this TXT answer appending it to the list */ - txt_curr = ares_malloc_data(ARES_DATATYPE_TXT_REPLY); - if (!txt_curr) - { - status = ARES_ENOMEM; - break; - } - if (txt_last) - { - txt_last->next = txt_curr; - } - else - { - txt_head = txt_curr; - } - txt_last = txt_curr; - /* * There may be multiple substrings in a single TXT record. Each * substring may be up to 255 characters in length, with a @@ -141,40 +123,62 @@ ares_parse_txt_reply (const unsigned char *abuf, int alen, * substrings contained therein. */ - /* Compute total length to allow a single memory allocation */ strptr = aptr; while (strptr < (aptr + rr_len)) { substr_len = (unsigned char)*strptr; - txt_curr->length += substr_len; - strptr += substr_len + 1; - } - - /* Including null byte */ - txt_curr->txt = malloc (txt_curr->length + 1); - if (txt_curr->txt == NULL) - { - status = ARES_ENOMEM; - break; - } + if (strptr + substr_len + 1 > aptr + rr_len) + { + status = ARES_EBADRESP; + break; + } + + /* Allocate storage for this TXT answer appending it to the list */ + txt_curr = ares_malloc_data(ex ? ARES_DATATYPE_TXT_EXT : + ARES_DATATYPE_TXT_REPLY); + if (!txt_curr) + { + status = ARES_ENOMEM; + break; + } + if (txt_last) + { + txt_last->next = txt_curr; + } + else + { + txt_head = txt_curr; + } + txt_last = txt_curr; + + if (ex) + txt_curr->record_start = (strptr == aptr); + txt_curr->length = substr_len; + txt_curr->txt = ares_malloc (substr_len + 1/* Including null byte */); + if (txt_curr->txt == NULL) + { + status = ARES_ENOMEM; + break; + } + + ++strptr; + memcpy ((char *) txt_curr->txt, strptr, substr_len); + + /* Make sure we NULL-terminate */ + txt_curr->txt[substr_len] = 0; - /* Step through the list of substrings, concatenating them */ - str_len = 0; - strptr = aptr; - while (strptr < (aptr + rr_len)) - { - substr_len = (unsigned char)*strptr; - strptr++; - memcpy ((char *) txt_curr->txt + str_len, strptr, substr_len); - str_len += substr_len; strptr += substr_len; } - /* Make sure we NULL-terminate */ - *((char *) txt_curr->txt + txt_curr->length) = '\0'; + } + + /* Propagate any failures */ + if (status != ARES_SUCCESS) + { + break; } /* Don't lose memory in the next iteration */ - free (rr_name); + ares_free (rr_name); rr_name = NULL; /* Move on to the next record */ @@ -182,9 +186,9 @@ ares_parse_txt_reply (const unsigned char *abuf, int alen, } if (hostname) - free (hostname); + ares_free (hostname); if (rr_name) - free (rr_name); + ares_free (rr_name); /* clean up on error */ if (status != ARES_SUCCESS) @@ -199,3 +203,18 @@ ares_parse_txt_reply (const unsigned char *abuf, int alen, return ARES_SUCCESS; } + +int +ares_parse_txt_reply (const unsigned char *abuf, int alen, + struct ares_txt_reply **txt_out) +{ + return ares__parse_txt_reply(abuf, alen, 0, (void **) txt_out); +} + + +int +ares_parse_txt_reply_ext (const unsigned char *abuf, int alen, + struct ares_txt_ext **txt_out) +{ + return ares__parse_txt_reply(abuf, alen, 1, (void **) txt_out); +} |