Import ares 1.7.0 helpers

8 files changed, 363 insertions, 95 deletions

diff --git a/server/resolv/ares/ares_data.c b/server/resolv/ares/ares_data.c
new file mode 100644
index 00000000..1cccaa55
--- /dev/null
+++ b/server/resolv/ares/ares_data.c
@@ -0,0 +1,140 @@
+/* $Id: ares_data.c,v 1.2 2009-11-20 09:06:33 yangtse Exp $ */
+
+/* Copyright (C) 2009 by Daniel Stenberg
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ */
+
+
+#include <stddef.h>
+#include <stdlib.h>
+
+#include "ares.h"
+#include "ares_data.h"
+
+/*
+** ares_free_data() - c-ares external API function.
+**
+** This function must be used by the application to free data memory that
+** has been internally allocated by some c-ares function and for which a
+** pointer has already been returned to the calling application. The list
+** of c-ares functions returning pointers that must be free'ed using this
+** function is:
+**
+**   ares_parse_srv_reply()
+**   ares_parse_txt_reply()
+*/
+
+void _ares_free_data(void *dataptr)
+{
+  struct ares_data *ptr;
+
+  if (!dataptr)
+    return;
+
+  ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
+
+  if (ptr->mark != ARES_DATATYPE_MARK)
+    return;
+
+  switch (ptr->type)
+    {
+      case ARES_DATATYPE_SRV_REPLY:
+
+        if (ptr->data.srv_reply.next)
+          _ares_free_data(ptr->data.srv_reply.next);
+        if (ptr->data.srv_reply.host)
+          free(ptr->data.srv_reply.host);
+        break;
+
+      case ARES_DATATYPE_TXT_REPLY:
+
+        if (ptr->data.txt_reply.next)
+          _ares_free_data(ptr->data.txt_reply.next);
+        if (ptr->data.txt_reply.txt)
+          free(ptr->data.txt_reply.txt);
+        break;
+
+      default:
+        return;
+    }
+
+  free(ptr);
+}
+
+
+/*
+** ares_malloc_data() - c-ares internal helper function.
+**
+** This function allocates memory for a c-ares private ares_data struct
+** for the specified ares_datatype, initializes c-ares private fields
+** and zero initializes those which later might be used from the public
+** API. It returns an interior pointer which can be passed by c-ares
+** functions to the calling application, and that must be free'ed using
+** c-ares external API function ares_free_data().
+*/
+
+void *_ares_malloc_data(ares_datatype type)
+{
+  struct ares_data *ptr;
+
+  ptr = malloc(sizeof(struct ares_data));
+  if (!ptr)
+    return NULL;
+
+  switch (type)
+    {
+      case ARES_DATATYPE_SRV_REPLY:
+        ptr->data.srv_reply.next = NULL;
+        ptr->data.srv_reply.host = NULL;
+        ptr->data.srv_reply.priority = 0;
+        ptr->data.srv_reply.weight = 0;
+        ptr->data.srv_reply.port = 0;
+        break;
+
+      case ARES_DATATYPE_TXT_REPLY:
+        ptr->data.txt_reply.next = NULL;
+        ptr->data.txt_reply.txt = NULL;
+        ptr->data.txt_reply.length  = 0;
+        break;
+
+      default:
+        free(ptr);
+        return NULL;
+    }
+
+  ptr->mark = ARES_DATATYPE_MARK;
+  ptr->type = type;
+
+  return &ptr->data;
+}
+
+
+/*
+** ares_get_datatype() - c-ares internal helper function.
+**
+** This function returns the ares_datatype of the data stored in a
+** private ares_data struct when given the public API pointer.
+*/
+
+ares_datatype ares_get_datatype(void * dataptr)
+{
+  struct ares_data *ptr;
+
+  ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
+
+  if (ptr->mark == ARES_DATATYPE_MARK)
+    return ptr->type;
+
+  return ARES_DATATYPE_UNKNOWN;
+}
diff --git a/server/resolv/ares/ares_data.h b/server/resolv/ares/ares_data.h
new file mode 100644
index 00000000..d3606314
--- /dev/null
+++ b/server/resolv/ares/ares_data.h
@@ -0,0 +1,68 @@
+/* $Id: ares_data.h,v 1.2 2009-11-23 12:03:33 yangtse Exp $ */
+
+/* Copyright (C) 2009 by Daniel Stenberg
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ */
+
+#ifndef HAVE_ARES_DATA
+#include "resolv/ares/ares_parse_txt_reply.h"
+#include "resolv/ares/ares_parse_srv_reply.h"
+#endif /* HAVE_ARES_DATA */
+
+typedef enum {
+  ARES_DATATYPE_UNKNOWN = 1,  /* unknown data type     - introduced in 1.7.0 */
+  ARES_DATATYPE_SRV_REPLY,    /* struct ares_srv_reply - introduced in 1.7.0 */
+  ARES_DATATYPE_TXT_REPLY,    /* struct ares_txt_reply - introduced in 1.7.0 */
+#if 0
+  ARES_DATATYPE_ADDR6TTL,     /* struct ares_addrttl   */
+  ARES_DATATYPE_ADDRTTL,      /* struct ares_addr6ttl  */
+  ARES_DATATYPE_HOSTENT,      /* struct hostent        */
+  ARES_DATATYPE_OPTIONS,      /* struct ares_options   */
+#endif
+  ARES_DATATYPE_LAST          /* not used              - introduced in 1.7.0 */
+} ares_datatype;
+
+#define ARES_DATATYPE_MARK 0xbead
+
+/*
+ * ares_data struct definition is internal to c-ares and shall not
+ * be exposed by the public API in order to allow future changes
+ * and extensions to it without breaking ABI.  This will be used
+ * internally by c-ares as the container of multiple types of data
+ * dynamically allocated for which a reference will be returned
+ * to the calling application.
+ *
+ * c-ares API functions returning a pointer to c-ares internally
+ * allocated data will actually be returning an interior pointer
+ * into this ares_data struct.
+ *
+ * All this is 'invisible' to the calling application, the only
+ * requirement is that this kind of data must be free'ed by the
+ * calling application using ares_free_data() with the pointer
+ * it has received from a previous c-ares function call.
+ */
+
+struct ares_data {
+  ares_datatype type;  /* Actual data type identifier. */
+  unsigned int  mark;  /* Private ares_data signature. */
+  union {
+    struct ares_txt_reply txt_reply;
+    struct ares_srv_reply srv_reply;
+  } data;
+};
+
+void *_ares_malloc_data(ares_datatype type);
+void _ares_free_data(void *dataptr);
+
+ares_datatype ares_get_datatype(void * dataptr);
diff --git a/server/resolv/ares/ares_parse_srv_reply.c b/server/resolv/ares/ares_parse_srv_reply.c
index 9745fb07..086c4dba 100644
--- a/server/resolv/ares/ares_parse_srv_reply.c
+++ b/server/resolv/ares/ares_parse_srv_reply.c
@@ -51,25 +51,24 @@
 #include "ares.h"
 /* this drags in some private macros c-ares uses */
 #include "ares_dns.h"
+#include "ares_data.h"
 
 #include "ares_parse_srv_reply.h"
 
 int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
-                           struct srv_reply **srv_out, int *nsrvreply)
+                           struct ares_srv_reply **srv_out)
 {
-  unsigned int qdcount, ancount;
-  const unsigned char *aptr;
-  int status, i, rr_type, rr_class, rr_len;
+  unsigned int qdcount, ancount, i;
+  const unsigned char *aptr, *vptr;
+  int status, rr_type, rr_class, rr_len;
   long len;
   char *hostname = NULL, *rr_name = NULL;
-  struct srv_reply *srv = NULL;
+  struct ares_srv_reply *srv_head = NULL;
+  struct ares_srv_reply *srv_last = NULL;
+  struct ares_srv_reply *srv_curr;
 
   /* Set *srv_out to NULL for all failure cases. */
-  if (srv_out)
-    *srv_out = NULL;
-  /* Same with *nsrvreply. */
-  if (nsrvreply)
-    *nsrvreply = 0;
+  *srv_out = NULL;
 
   /* Give up if abuf doesn't have room for a header. */
   if (alen < HFIXEDSZ)
@@ -96,14 +95,6 @@ int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
     }
   aptr += len + QFIXEDSZ;
 
-  /* Allocate srv_reply array; ancount gives an upper bound */
-  srv = malloc ((ancount) * sizeof (struct srv_reply));
-  if (!srv)
-    {
-      free (hostname);
-      return ARES_ENOMEM;
-    }
-
   /* Examine each answer resource record (RR) in turn. */
   for (i = 0; i < (int) ancount; i++)
     {
@@ -134,40 +125,59 @@ int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
               break;
             }
 
-          srv[i].priority = ntohs (*((const uint16_t *)aptr));
-          aptr += sizeof(uint16_t);
-          srv[i].weight = ntohs (*((const uint16_t *)aptr));
-          aptr += sizeof(uint16_t);
-          srv[i].port = ntohs (*((const uint16_t *)aptr));
-          aptr += sizeof(uint16_t);
+          /* Allocate storage for this SRV answer appending it to the list */
+          srv_curr = _ares_malloc_data(ARES_DATATYPE_SRV_REPLY);
+          if (!srv_curr)
+            {
+              status = ARES_ENOMEM;
+              break;
+            }
+          if (srv_last)
+            {
+              srv_last->next = srv_curr;
+            }
+          else
+            {
+              srv_head = srv_curr;
+            }
+          srv_last = srv_curr;
+
+          vptr = aptr;
+          srv_curr->priority = ntohs (*((const unsigned short *)vptr));
+          vptr += sizeof(const unsigned short);
+          srv_curr->weight = ntohs (*((const unsigned short *)vptr));
+          vptr += sizeof(const unsigned short);
+          srv_curr->port = ntohs (*((const unsigned short *)vptr));
+          vptr += sizeof(const unsigned short);
 
-          status = ares_expand_name (aptr, abuf, alen, &srv[i].host, &len);
+          status = ares_expand_name (vptr, abuf, alen, &srv_curr->host, &len);
           if (status != ARES_SUCCESS)
             break;
+        }
 
-          /* Move on to the next record */
-          aptr += len;
+      /* Don't lose memory in the next iteration */
+      free(rr_name);
+      rr_name = NULL;
 
-          /* Don't lose memory in the next iteration */
-          free (rr_name);
-          rr_name = NULL;
-        }
+      /* Move on to the next record */
+      aptr += rr_len;
     }
 
+  if (hostname)
+    free (hostname);
+  if (rr_name)
+    free (rr_name);
+
   /* clean up on error */
   if (status != ARES_SUCCESS)
     {
-      free (srv);
-      free (hostname);
-      free (rr_name);
+      if (srv_head)
+        _ares_free_data (srv_head);
       return status;
     }
 
   /* everything looks fine, return the data */
-  *srv_out = srv;
-  *nsrvreply = ancount;
+  *srv_out = srv_head;
 
-  free (hostname);
-  free (rr_name);
-  return status;
+  return ARES_SUCCESS;
 }
diff --git a/server/resolv/ares/ares_parse_srv_reply.h b/server/resolv/ares/ares_parse_srv_reply.h
index caf93cd2..29c6e08d 100644
--- a/server/resolv/ares/ares_parse_srv_reply.h
+++ b/server/resolv/ares/ares_parse_srv_reply.h
@@ -21,14 +21,15 @@
 #ifndef __ARES_PARSE_SRV_REPLY_H__
 #define __ARES_PARSE_SRV_REPLY_H__
 
-struct srv_reply {
-    u_int16_t weight;
-    u_int16_t priority;
-    u_int16_t port;
-    char *host;
+struct ares_srv_reply {
+    struct ares_srv_reply  *next;
+    char                   *host;
+    unsigned short          priority;
+    unsigned short          weight;
+    unsigned short          port;
 };
 
 int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
-                           struct srv_reply **srv_out, int *nsrvreply);
+                           struct ares_srv_reply **srv_out);
 
 #endif /* __ARES_PARSE_SRV_REPLY_H__ */
diff --git a/server/resolv/ares/ares_parse_txt_reply.c b/server/resolv/ares/ares_parse_txt_reply.c
index feb6af23..d710e8f9 100644
--- a/server/resolv/ares/ares_parse_txt_reply.c
+++ b/server/resolv/ares/ares_parse_txt_reply.c
@@ -50,21 +50,26 @@
 #include "ares.h"
 /* this drags in some private macros c-ares uses */
 #include "ares_dns.h"
+#include "ares_data.h"
 
 #include "ares_parse_txt_reply.h"
 
-int _ares_parse_txt_reply(const unsigned char* abuf, int alen,
-                          struct txt_reply **txt_out, int *ntxtreply)
+int _ares_parse_txt_reply (const unsigned char *abuf, int alen,
+                           struct ares_txt_reply **txt_out)
 {
-  unsigned int qdcount, ancount;
+  size_t substr_len, str_len;
+  unsigned int qdcount, ancount, i;
   const unsigned char *aptr;
-  int status, i, rr_type, rr_class, rr_len;
+  const unsigned char *strptr;
+  int status, rr_type, rr_class, rr_len;
   long len;
   char *hostname = NULL, *rr_name = NULL;
-  struct txt_reply *txt = NULL;
+  struct ares_txt_reply *txt_head = NULL;
+  struct ares_txt_reply *txt_last = NULL;
+  struct ares_txt_reply *txt_curr;
 
-  if (txt_out)
-      *txt_out = NULL;
+  /* Set *txt_out to NULL for all failure cases. */
+  *txt_out = NULL;
 
   /* Give up if abuf doesn't have room for a header. */
   if (alen < HFIXEDSZ)
@@ -91,29 +96,21 @@ int _ares_parse_txt_reply(const unsigned char* abuf, int alen,
     }
   aptr += len + QFIXEDSZ;
 
-  /* Allocate txt_reply array; ancount gives an upper bound */
-  txt = malloc ((ancount) * sizeof (struct txt_reply));
-  if (!txt)
-    {
-      free (hostname);
-      return ARES_ENOMEM;
-    }
-
   /* Examine each answer resource record (RR) in turn. */
   for (i = 0; i < (int) ancount; i++)
     {
       /* Decode the RR up to the data field. */
       status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
       if (status != ARES_SUCCESS)
-	{
-	  break;
-	}
+       {
+         break;
+       }
       aptr += len;
       if (aptr + RRFIXEDSZ > abuf + alen)
-	{
-	  status = ARES_EBADRESP;
-	  break;
-	}
+       {
+         status = ARES_EBADRESP;
+         break;
+       }
       rr_type = DNS_RR_TYPE(aptr);
       rr_class = DNS_RR_CLASS(aptr);
       rr_len = DNS_RR_LEN(aptr);
@@ -121,37 +118,87 @@ int _ares_parse_txt_reply(const unsigned char* abuf, int alen,
 
       /* Check if we are really looking at a TXT record */
       if (rr_class == C_IN && rr_type == T_TXT)
-	{
-            /* Grab the TXT payload */
-            txt[i].length = rr_len;
-            txt[i].txt = malloc(sizeof(unsigned char) * rr_len);
-            if (txt[i].txt == NULL)
+        {
+          /* 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;
             }
-            memcpy((void *) txt[i].txt, aptr+1, sizeof(unsigned char) * rr_len);
-            /* Move on to the next record */
-            aptr += rr_len;
+          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
+           * "length byte" indicating the size of the substring payload.
+           * RDATA contains both the length-bytes and payloads of all
+           * 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;
+            }
+
+          /* 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';
         }
 
       /* Don't lose memory in the next iteration */
       free(rr_name);
       rr_name = NULL;
+
+      /* Move on to the next record */
+      aptr += rr_len;
     }
 
-  free(hostname);
-  free(rr_name);
+  if (hostname)
+    free (hostname);
+  if (rr_name)
+    free (rr_name);
 
   /* clean up on error */
   if (status != ARES_SUCCESS)
     {
-      free (txt);
+      if (txt_head)
+        _ares_free_data (txt_head);
       return status;
     }
 
   /* everything looks fine, return the data */
-  *txt_out = txt;
-  *ntxtreply = ancount;
-  return 0;
+  *txt_out = txt_head;
+
+  return ARES_SUCCESS;
 }
diff --git a/server/resolv/ares/ares_parse_txt_reply.h b/server/resolv/ares/ares_parse_txt_reply.h
index 9fd42787..216e2c0d 100644
--- a/server/resolv/ares/ares_parse_txt_reply.h
+++ b/server/resolv/ares/ares_parse_txt_reply.h
@@ -21,12 +21,13 @@
 #ifndef __ARES_PARSE_TXT_REPLY_H__
 #define __ARES_PARSE_TXT_REPLY_H__
 
-struct txt_reply {
-    int length;         /* length of the text */
-    unsigned char *txt; /* may contain nulls */
+struct ares_txt_reply {
+    struct ares_txt_reply  *next;
+    unsigned char          *txt;
+    size_t                  length;  /* length excludes null termination */
 };
 
 int _ares_parse_txt_reply(const unsigned char* abuf, int alen,
-                          struct txt_reply **txt_out, int *ntxtreply);
+                          struct ares_txt_reply **txt_out);
 
 #endif /* __ARES_PARSE_TXT_REPLY_H__ */
diff --git a/server/resolv/async_resolv.c b/server/resolv/async_resolv.c
index be2107a2..afad4107 100644
--- a/server/resolv/async_resolv.c
+++ b/server/resolv/async_resolv.c
@@ -42,15 +42,16 @@
 #include "util/dlinklist.h"
 #include "util/util.h"
 
-#ifndef HAVE_ARES_PARSE_SRV
+#ifndef HAVE_ARES_DATA
 #define ares_parse_srv_reply(abuf, alen, srv_out) \
     _ares_parse_srv_reply(abuf, alen, srv_out)
-#endif /* HAVE_ARES_PARSE_SRV */
-
-#ifndef HAVE_ARES_PARSE_TXT
 #define ares_parse_txt_reply(abuf, alen, txt_out) \
     _ares_parse_txt_reply(abuf, alen, txt_out)
-#endif /* HAVE_ARES_PARSE_TXT */
+#define ares_free_data(dataptr) \
+    _ares_free_data(dataptr)
+#define ares_malloc_data(data) \
+    _ares_malloc_data(data)
+#endif /* HAVE_ARES_DATA */
 
 struct fd_watch {
     struct fd_watch *prev;
diff --git a/server/resolv/async_resolv.h b/server/resolv/async_resolv.h
index 9d080ec6..dab2fdfc 100644
--- a/server/resolv/async_resolv.h
+++ b/server/resolv/async_resolv.h
@@ -29,13 +29,13 @@
 #include <netdb.h>
 #include <ares.h>
 
-#ifndef HAVE_ARES_PARSE_TXT
-#include "resolv/ares/ares_parse_txt_reply.h"
-#endif /* HAVE_ARES_PARSE_TXT */
+#include "config.h"
 
-#ifndef HAVE_ARES_PARSE_SRV
+#ifndef HAVE_ARES_DATA
 #include "resolv/ares/ares_parse_srv_reply.h"
-#endif /* HAVE_ARES_PARSE_SRV */
+#include "resolv/ares/ares_parse_txt_reply.h"
+#include "resolv/ares/ares_data.h"
+#endif /* HAVE_ARES_DATA */
 
 /*
  * An opaque structure which holds context for a module using the async