-define gnsrecord plugin for DNS

1 files changed, 553 insertions, 0 deletions

diff --git a/src/gnsrecord/plugin_gnsrecord_dns.c b/src/gnsrecord/plugin_gnsrecord_dns.c
new file mode 100644
index 000000000..e5475118d
--- /dev/null
+++ b/src/gnsrecord/plugin_gnsrecord_dns.c
@@ -0,0 +1,553 @@
+/*
+     This file is part of GNUnet
+     (C) 2013 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file gnsrecord/plugin_gnsrecord_dns.c
+ * @brief gnsrecord plugin to provide the API for basic DNS records
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_dnsparser_lib.h"
+#include "gnunet_gnsrecord_plugin.h"
+
+
+/**
+ * Convert the 'value' of a record to a string.
+ *
+ * @param cls closure, unused
+ * @param type type of the record
+ * @param data value in binary encoding
+ * @param data_size number of bytes in @a data
+ * @return NULL on error, otherwise human-readable representation of the value
+ */
+static char *
+dns_value_to_string (void *cls,
+                     uint32_t type,
+                     const void *data,
+                     size_t data_size)
+{
+  const char *cdata;
+  char* result;
+  char tmp[INET6_ADDRSTRLEN];
+
+  switch (type)
+  {
+  case GNUNET_DNSPARSER_TYPE_A:
+    if (data_size != sizeof (struct in_addr))
+      return NULL;
+    if (NULL == inet_ntop (AF_INET, data, tmp, sizeof (tmp)))
+      return NULL;
+    return GNUNET_strdup (tmp);
+  case GNUNET_DNSPARSER_TYPE_NS:
+    {
+      char *ns;
+      size_t off;
+
+      off = 0;
+      ns = GNUNET_DNSPARSER_parse_name (data,
+                                        data_size,
+                                        &off);
+      if ( (NULL == ns) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        return NULL;
+      }
+      return ns;
+    }
+  case GNUNET_DNSPARSER_TYPE_CNAME:
+    {
+      char *cname;
+      size_t off;
+
+      off = 0;
+      cname = GNUNET_DNSPARSER_parse_name (data,
+                                           data_size,
+                                           &off);
+      if ( (NULL == cname) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        GNUNET_free_non_null (cname);
+        return NULL;
+      }
+      return cname;
+    }
+  case GNUNET_DNSPARSER_TYPE_SOA:
+    {
+      struct GNUNET_DNSPARSER_SoaRecord *soa;
+      size_t off;
+
+      off = 0;
+      soa = GNUNET_DNSPARSER_parse_soa (data,
+                                        data_size,
+                                        &off);
+      if ( (NULL == soa) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        return NULL;
+      }
+      GNUNET_asprintf (&result,
+                       "rname=%s mname=%s %lu,%lu,%lu,%lu,%lu",
+                       soa->rname,
+                       soa->mname,
+                       soa->serial,
+                       soa->refresh,
+                       soa->retry,
+                       soa->expire,
+                       soa->minimum_ttl);
+      GNUNET_DNSPARSER_free_soa (soa);
+      return result;
+    }
+  case GNUNET_DNSPARSER_TYPE_PTR:
+    {
+      char *ptr;
+      size_t off;
+
+      off = 0;
+      ptr = GNUNET_DNSPARSER_parse_name (data,
+                                           data_size,
+                                           &off);
+      if ( (NULL == ptr) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        GNUNET_free_non_null (ptr);
+        return NULL;
+      }
+      return ptr;
+    }
+  case GNUNET_DNSPARSER_TYPE_MX:
+    {
+      struct GNUNET_DNSPARSER_MxRecord *mx;
+      size_t off;
+
+      off = 0;
+      mx = GNUNET_DNSPARSER_parse_mx (data,
+                                      data_size,
+                                      &off);
+      if ( (NULL == mx) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        GNUNET_free_non_null (mx);
+        return NULL;
+      }
+      GNUNET_asprintf (&result,
+                       "%hu,%s",
+                       mx->preference,
+                       mx->mxhost);
+      GNUNET_DNSPARSER_free_mx (mx);
+      return result;
+    }
+  case GNUNET_DNSPARSER_TYPE_TXT:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_DNSPARSER_TYPE_AAAA:
+    if (data_size != sizeof (struct in6_addr))
+      return NULL;
+    if (NULL == inet_ntop (AF_INET6, data, tmp, sizeof (tmp)))
+      return NULL;
+    return GNUNET_strdup (tmp);
+  case GNUNET_DNSPARSER_TYPE_SRV:
+    {
+      struct GNUNET_DNSPARSER_SrvRecord *srv;
+      size_t off;
+
+      off = 0;
+      srv = GNUNET_DNSPARSER_parse_srv ("+", /* FIXME: is this OK? */
+                                        data,
+                                        data_size,
+                                        &off);
+      if ( (NULL == srv) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        return NULL;
+      }
+      GNUNET_asprintf (&result,
+                       "%d %d %d _%s._%s.%s",
+                       srv->priority,
+                       srv->weight,
+                       srv->port,
+                       srv->service,
+                       srv->proto,
+                       srv->domain_name);
+      GNUNET_DNSPARSER_free_srv (srv);
+      return result;
+    }
+  case GNUNET_DNSPARSER_TYPE_TLSA:
+    {
+      const struct GNUNET_TUN_DnsTlsaRecord *tlsa;
+      char* tlsa_str;
+
+      cdata = data;
+      if ( (data_size <= sizeof (struct GNUNET_TUN_DnsTlsaRecord)) ||
+           ('\0' != cdata[data_size - 1]) )
+        return NULL; /* malformed */
+      tlsa = data;
+      if (0 == GNUNET_asprintf (&tlsa_str,
+                                "%c %c %c %s",
+                                tlsa->usage,
+                                tlsa->selector,
+                                tlsa->matching_type,
+                                (const char *) &tlsa[1]))
+      {
+        GNUNET_free (tlsa_str);
+        return NULL;
+      }
+      return tlsa_str;
+    }
+  default:
+    return NULL;
+  }
+}
+
+
+/**
+ * Convert human-readable version of a 'value' of a record to the binary
+ * representation.
+ *
+ * @param cls closure, unused
+ * @param type type of the record
+ * @param s human-readable string
+ * @param data set to value in binary encoding (will be allocated)
+ * @param data_size set to number of bytes in @a data
+ * @return #GNUNET_OK on success
+ */
+static int
+dns_string_to_value (void *cls,
+                     uint32_t type,
+                     const char *s,
+                     void **data,
+                     size_t *data_size)
+{
+  struct in_addr value_a;
+  struct in6_addr value_aaaa;
+  struct GNUNET_TUN_DnsTlsaRecord *tlsa;
+
+  if (NULL == s)
+    return GNUNET_SYSERR;
+  switch (type)
+  {
+  case GNUNET_DNSPARSER_TYPE_A:
+    if (1 != inet_pton (AF_INET, s, &value_a))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse IPv4 address `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data = GNUNET_malloc (sizeof (struct in_addr));
+    memcpy (*data, &value_a, sizeof (value_a));
+    *data_size = sizeof (value_a);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_NS:
+    {
+      char nsbuf[256];
+      size_t off;
+
+      off = 0;
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_name (nsbuf,
+                                             sizeof (nsbuf),
+                                             &off,
+                                             s))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize NS record with value `%s'\n"),
+             s);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, nsbuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_DNSPARSER_TYPE_CNAME:
+    {
+      char cnamebuf[256];
+      size_t off;
+
+      off = 0;
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_name (cnamebuf,
+                                             sizeof (cnamebuf),
+                                             &off,
+                                             s))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize CNAME record with value `%s'\n"),
+             s);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, cnamebuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_DNSPARSER_TYPE_SOA:
+    {
+      struct GNUNET_DNSPARSER_SoaRecord soa;
+      char soabuf[540];
+      char soa_rname[253 + 1];
+      char soa_mname[253 + 1];
+      unsigned int soa_serial;
+      unsigned int soa_refresh;
+      unsigned int soa_retry;
+      unsigned int soa_expire;
+      unsigned int soa_min;
+      size_t off;
+
+      if (7 != SSCANF (s,
+                       "rname=%253s mname=%253s %u,%u,%u,%u,%u",
+                       soa_rname, soa_mname,
+                       &soa_serial, &soa_refresh, &soa_retry, &soa_expire, &soa_min))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Unable to parse SOA record `%s'\n"),
+             s);
+        return GNUNET_SYSERR;
+      }
+      soa.mname = soa_mname;
+      soa.rname = soa_rname;
+      soa.serial = (uint32_t) soa_serial;
+      soa.refresh =(uint32_t)  soa_refresh;
+      soa.retry = (uint32_t) soa_retry;
+      soa.expire = (uint32_t) soa_expire;
+      soa.minimum_ttl = (uint32_t) soa_min;
+      off = 0;
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_soa (soabuf,
+                                            sizeof (soabuf),
+                                            &off,
+                                            &soa))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize SOA record with mname `%s' and rname `%s'\n"),
+             soa_mname,
+             soa_rname);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, soabuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_DNSPARSER_TYPE_PTR:
+    {
+      char ptrbuf[256];
+      size_t off;
+
+      off = 0;
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_name (ptrbuf,
+                                             sizeof (ptrbuf),
+                                             &off,
+                                             s))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize PTR record with value `%s'\n"),
+             s);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, ptrbuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_DNSPARSER_TYPE_MX:
+    {
+      struct GNUNET_DNSPARSER_MxRecord mx;
+      char mxbuf[258];
+      char mxhost[253 + 1];
+      uint16_t mx_pref;
+      size_t off;
+
+      if (2 != SSCANF(s, "%hu,%253s", &mx_pref, mxhost))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Unable to parse MX record `%s'\n"),
+             s);
+      return GNUNET_SYSERR;
+      }
+      mx.preference = mx_pref;
+      mx.mxhost = mxhost;
+      off = 0;
+
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_mx (mxbuf,
+                                           sizeof (mxbuf),
+                                           &off,
+                                           &mx))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize MX record with hostname `%s'\n"),
+             mxhost);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, mxbuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_DNSPARSER_TYPE_SRV:
+    GNUNET_break (0); // FIXME: not implemented!
+    return GNUNET_SYSERR;
+  case GNUNET_DNSPARSER_TYPE_TXT:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_AAAA:
+    if (1 != inet_pton (AF_INET6, s, &value_aaaa))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+           _("Unable to parse IPv6 address `%s'\n"),
+           s);
+      return GNUNET_SYSERR;
+    }
+    *data = GNUNET_malloc (sizeof (struct in6_addr));
+    *data_size = sizeof (struct in6_addr);
+    memcpy (*data, &value_aaaa, sizeof (value_aaaa));
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_TLSA:
+    *data_size = sizeof (struct GNUNET_TUN_DnsTlsaRecord) + strlen (s) - 6;
+    *data = tlsa = GNUNET_malloc (*data_size);
+    if (4 != SSCANF (s, "%c %c %c %s",
+                     &tlsa->usage,
+                     &tlsa->selector,
+                     &tlsa->matching_type,
+                     (char*)&tlsa[1]))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse TLSA record string `%s'\n"),
+                  s);
+      *data_size = 0;
+      GNUNET_free (tlsa);
+      return GNUNET_SYSERR;
+    }
+    return GNUNET_OK;
+  default:
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Mapping of record type numbers to human-readable
+ * record type names.
+ */
+static struct {
+  const char *name;
+  uint32_t number;
+} name_map[] = {
+  { "A", GNUNET_DNSPARSER_TYPE_A },
+  { "NS", GNUNET_DNSPARSER_TYPE_NS },
+  { "CNAME", GNUNET_DNSPARSER_TYPE_CNAME },
+  { "SOA", GNUNET_DNSPARSER_TYPE_SOA },
+  { "PTR", GNUNET_DNSPARSER_TYPE_PTR },
+  { "MX", GNUNET_DNSPARSER_TYPE_MX },
+  { "TXT", GNUNET_DNSPARSER_TYPE_TXT },
+  { "AAAA", GNUNET_DNSPARSER_TYPE_AAAA },
+  { "TLSA", GNUNET_DNSPARSER_TYPE_TLSA },
+  { NULL, UINT32_MAX }
+};
+
+
+/**
+ * Convert a type name (i.e. "AAAA") to the corresponding number.
+ *
+ * @param cls closure, unused
+ * @param dns_typename name to convert
+ * @return corresponding number, UINT32_MAX on error
+ */
+static uint32_t
+dns_typename_to_number (void *cls,
+                        const char *dns_typename)
+{
+  unsigned int i;
+
+  i=0;
+  while ( (name_map[i].name != NULL) &&
+          (0 != strcasecmp (dns_typename, name_map[i].name)) )
+    i++;
+  return name_map[i].number;
+}
+
+
+/**
+ * Convert a type number (i.e. 1) to the corresponding type string (i.e. "A")
+ *
+ * @param cls closure, unused
+ * @param type number of a type to convert
+ * @return corresponding typestring, NULL on error
+ */
+static const char *
+dns_number_to_typename (void *cls,
+                        uint32_t type)
+{
+  unsigned int i;
+
+  i=0;
+  while ( (name_map[i].name != NULL) &&
+          (type != name_map[i].number) )
+    i++;
+  return name_map[i].name;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls NULL
+ * @return the exported block API
+ */
+void *
+libgnunet_plugin_gnsrecord_dns_init (void *cls)
+{
+  struct GNUNET_GNSRECORD_PluginFunctions *api;
+
+  api = GNUNET_new (struct GNUNET_GNSRECORD_PluginFunctions);
+  api->value_to_string = &dns_value_to_string;
+  api->string_to_value = &dns_string_to_value;
+  api->typename_to_number = &dns_typename_to_number;
+  api->number_to_typename = &dns_number_to_typename;
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the return value from #libgnunet_plugin_block_test_init
+ * @return NULL
+ */
+void *
+libgnunet_plugin_gnsrecord_dns_done (void *cls)
+{
+  struct GNUNET_GNSRECORD_PluginFunctions *api = cls;
+
+  GNUNET_free (api);
+  return NULL;
+}
+
+/* end of plugin_gnsrecord_dns.c */