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-rw-r--r--src/nt/nt.c410
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diff --git a/src/nt/nt.c b/src/nt/nt.c
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+/*
+ This file is part of GNUnet.
+ Copyright (C) 2010-2015, 2018 GNUnet e.V.
+
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ 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
+ Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @file nt/nt_api_scanner.c
+ * @brief LAN interface scanning to determine IPs in LAN
+ * @author Christian Grothoff
+ * @author Matthias Wachs
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_nt_lib.h"
+
+/**
+ * How frequently do we scan the interfaces for changes to the addresses?
+ */
+#define INTERFACE_PROCESSING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
+
+
+/**
+ * Convert a `enum GNUNET_NetworkType` to a string
+ *
+ * @param net the network type
+ * @return a string or NULL if invalid
+ */
+const char *
+GNUNET_NT_to_string (enum GNUNET_NetworkType net)
+{
+ switch (net)
+ {
+ case GNUNET_NT_UNSPECIFIED:
+ return "UNSPECIFIED";
+ case GNUNET_NT_LOOPBACK:
+ return "LOOPBACK";
+ case GNUNET_NT_LAN:
+ return "LAN";
+ case GNUNET_NT_WAN:
+ return "WAN";
+ case GNUNET_NT_WLAN:
+ return "WLAN";
+ case GNUNET_NT_BT:
+ return "BLUETOOTH";
+ default:
+ return NULL;
+ }
+}
+
+
+/**
+ * We keep a list of our local networks so we can answer
+ * LAN vs. WAN questions. Note: WLAN is not detected yet.
+ * (maybe we can do that heuristically based on interface
+ * name in the future?).
+ */
+struct NT_Network
+{
+ /**
+ * Kept in a DLL.
+ */
+ struct NT_Network *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct NT_Network *prev;
+
+ /**
+ * Network address.
+ */
+ struct sockaddr *network;
+
+ /**
+ * Netmask to determine what is in the LAN.
+ */
+ struct sockaddr *netmask;
+
+ /**
+ * How long are @e network and @e netmask?
+ */
+ socklen_t length;
+};
+
+
+/**
+ * Handle to the interface scanner.
+ */
+struct GNUNET_NT_InterfaceScanner
+{
+
+ /**
+ * Head of LAN networks list.
+ */
+ struct NT_Network *net_head;
+
+ /**
+ * Tail of LAN networks list.
+ */
+ struct NT_Network *net_tail;
+
+ /**
+ * Task for periodically refreshing our LAN network list.
+ */
+ struct GNUNET_SCHEDULER_Task *interface_task;
+
+};
+
+
+/**
+ * Delete all entries from the current network list.
+ *
+ * @param is scanner to clean up
+ */
+static void
+delete_networks (struct GNUNET_NT_InterfaceScanner *is)
+{
+ struct NT_Network *cur;
+
+ while (NULL != (cur = is->net_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (is->net_head,
+ is->net_tail,
+ cur);
+ GNUNET_free (cur);
+ }
+}
+
+
+/**
+ * Function invoked for each interface found. Adds the interface's
+ * network addresses to the respective DLL, so we can distinguish
+ * between LAN and WAN.
+ *
+ * @param cls closure with the `struct GNUNET_NT_InterfaceScanner`
+ * @param name name of the interface (can be NULL for unknown)
+ * @param isDefault is this presumably the default interface
+ * @param addr address of this interface (can be NULL for unknown or unassigned)
+ * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
+ * @param netmask the network mask (can be NULL for unknown or unassigned)
+ * @param addrlen length of the address
+ * @return #GNUNET_OK to continue iteration
+ */
+static int
+interface_proc (void *cls,
+ const char *name,
+ int isDefault,
+ const struct sockaddr *addr,
+ const struct sockaddr *broadcast_addr,
+ const struct sockaddr *netmask,
+ socklen_t addrlen)
+{
+ struct GNUNET_NT_InterfaceScanner *is = cls;
+ /* Calculate network */
+ struct NT_Network *net = NULL;
+
+ /* Skipping IPv4 loopback addresses since we have special check */
+ if (addr->sa_family == AF_INET)
+ {
+ const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
+
+ if ((a4->sin_addr.s_addr & htonl(0xff000000)) == htonl (0x7f000000))
+ return GNUNET_OK;
+ }
+ /* Skipping IPv6 loopback addresses since we have special check */
+ if (addr->sa_family == AF_INET6)
+ {
+ const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
+ if (IN6_IS_ADDR_LOOPBACK (&a6->sin6_addr))
+ return GNUNET_OK;
+ }
+
+ if (addr->sa_family == AF_INET)
+ {
+ const struct sockaddr_in *addr4 = (const struct sockaddr_in *) addr;
+ const struct sockaddr_in *netmask4 = (const struct sockaddr_in *) netmask;
+ struct sockaddr_in *tmp;
+ struct sockaddr_in network4;
+
+ net = GNUNET_malloc (sizeof (struct NT_Network) + 2 * sizeof (struct sockaddr_in));
+ tmp = (struct sockaddr_in *) &net[1];
+ net->network = (struct sockaddr *) &tmp[0];
+ net->netmask = (struct sockaddr *) &tmp[1];
+ net->length = addrlen;
+
+ memset (&network4, 0, sizeof (network4));
+ network4.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ network4.sin_len = sizeof (network4);
+#endif
+ network4.sin_addr.s_addr = (addr4->sin_addr.s_addr & netmask4->sin_addr.s_addr);
+
+ GNUNET_memcpy (net->netmask, netmask4, sizeof (struct sockaddr_in));
+ GNUNET_memcpy (net->network, &network4, sizeof (struct sockaddr_in));
+ }
+
+ if (addr->sa_family == AF_INET6)
+ {
+ const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *) addr;
+ const struct sockaddr_in6 *netmask6 = (const struct sockaddr_in6 *) netmask;
+ struct sockaddr_in6 * tmp;
+ struct sockaddr_in6 network6;
+
+ net = GNUNET_malloc (sizeof (struct NT_Network) + 2 * sizeof (struct sockaddr_in6));
+ tmp = (struct sockaddr_in6 *) &net[1];
+ net->network = (struct sockaddr *) &tmp[0];
+ net->netmask = (struct sockaddr *) &tmp[1];
+ net->length = addrlen;
+
+ memset (&network6, 0, sizeof (network6));
+ network6.sin6_family = AF_INET6;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ network6.sin6_len = sizeof (network6);
+#endif
+ unsigned int c = 0;
+ uint32_t *addr_elem = (uint32_t *) &addr6->sin6_addr;
+ uint32_t *mask_elem = (uint32_t *) &netmask6->sin6_addr;
+ uint32_t *net_elem = (uint32_t *) &network6.sin6_addr;
+ for (c = 0; c < 4; c++)
+ net_elem[c] = addr_elem[c] & mask_elem[c];
+
+ GNUNET_memcpy (net->netmask, netmask6, sizeof (struct sockaddr_in6));
+ GNUNET_memcpy (net->network, &network6, sizeof (struct sockaddr_in6));
+ }
+ if (NULL == net)
+ return GNUNET_OK; /* odd / unsupported address family */
+
+ /* Store in list */
+#if VERBOSE_NT
+ char * netmask = GNUNET_strdup (GNUNET_a2s((struct sockaddr *) net->netmask, addrlen));
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+ "nt",
+ "Adding network `%s', netmask `%s'\n",
+ GNUNET_a2s ((struct sockaddr *) net->network,
+ addrlen),
+ netmask);
+ GNUNET_free (netmask);
+#endif
+ GNUNET_CONTAINER_DLL_insert (is->net_head,
+ is->net_tail,
+ net);
+
+ return GNUNET_OK;
+}
+
+
+/**
+ * Periodically get list of network addresses from our interfaces.
+ *
+ * @param cls closure
+ */
+static void
+get_addresses (void *cls)
+{
+ struct GNUNET_NT_InterfaceScanner *is = cls;
+
+ is->interface_task = NULL;
+ delete_networks (is);
+ GNUNET_OS_network_interfaces_list (&interface_proc,
+ is);
+ is->interface_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_PROCESSING_INTERVAL,
+ &get_addresses,
+ is);
+}
+
+
+/**
+ * Returns where the address is located: LAN or WAN or ...
+ *
+ * @param is the interface scanner handle
+ * @param addr address
+ * @param addrlen address length
+ * @return type of the network the address belongs to
+ */
+enum GNUNET_NetworkType
+GNUNET_NT_scanner_address_get_type (struct GNUNET_NT_InterfaceScanner *is,
+ const struct sockaddr *addr,
+ socklen_t addrlen)
+{
+ struct NT_Network *cur = is->net_head;
+ enum GNUNET_NetworkType type = GNUNET_NT_UNSPECIFIED;
+
+ switch (addr->sa_family)
+ {
+ case AF_UNIX:
+ type = GNUNET_NT_LOOPBACK;
+ break;
+ case AF_INET:
+ {
+ const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
+
+ if ((a4->sin_addr.s_addr & htonl(0xff000000)) == htonl (0x7f000000))
+ type = GNUNET_NT_LOOPBACK;
+ break;
+ }
+ case AF_INET6:
+ {
+ const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
+
+ if (IN6_IS_ADDR_LOOPBACK (&a6->sin6_addr))
+ type = GNUNET_NT_LOOPBACK;
+ break;
+ }
+ default:
+ GNUNET_break (0);
+ break;
+ }
+
+ /* Check local networks */
+ while ((NULL != cur) && (GNUNET_NT_UNSPECIFIED == type))
+ {
+ if (addrlen != cur->length)
+ {
+ cur = cur->next;
+ continue;
+ }
+ if (addr->sa_family == AF_INET)
+ {
+ const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
+ const struct sockaddr_in *net4 = (const struct sockaddr_in *) cur->network;
+ const struct sockaddr_in *mask4 = (const struct sockaddr_in *) cur->netmask;
+
+ if (((a4->sin_addr.s_addr & mask4->sin_addr.s_addr)) == net4->sin_addr.s_addr)
+ type = GNUNET_NT_LAN;
+ }
+ if (addr->sa_family == AF_INET6)
+ {
+ const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
+ const struct sockaddr_in6 *net6 = (const struct sockaddr_in6 *) cur->network;
+ const struct sockaddr_in6 *mask6 = (const struct sockaddr_in6 *) cur->netmask;
+
+ int res = GNUNET_YES;
+ int c = 0;
+ uint32_t *addr_elem = (uint32_t *) &a6->sin6_addr;
+ uint32_t *mask_elem = (uint32_t *) &mask6->sin6_addr;
+ uint32_t *net_elem = (uint32_t *) &net6->sin6_addr;
+ for (c = 0; c < 4; c++)
+ if ((addr_elem[c] & mask_elem[c]) != net_elem[c])
+ res = GNUNET_NO;
+
+ if (res == GNUNET_YES)
+ type = GNUNET_NT_LAN;
+ }
+ cur = cur->next;
+ }
+
+ /* no local network found for this address, default: WAN */
+ if (type == GNUNET_NT_UNSPECIFIED)
+ type = GNUNET_NT_WAN;
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+ "nt-scanner-api",
+ "`%s' is in network `%s'\n",
+ GNUNET_a2s (addr,
+ addrlen),
+ GNUNET_NT_to_string (type));
+ return type;
+}
+
+
+/**
+ * Initialize the interface scanner.
+ *
+ * @return interface scanner
+ */
+struct GNUNET_NT_InterfaceScanner *
+GNUNET_NT_scanner_init ()
+{
+ struct GNUNET_NT_InterfaceScanner *is;
+
+ is = GNUNET_new (struct GNUNET_NT_InterfaceScanner);
+ GNUNET_OS_network_interfaces_list (&interface_proc,
+ is);
+ is->interface_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_PROCESSING_INTERVAL,
+ &get_addresses,
+ is);
+ return is;
+}
+
+
+/**
+ * Client is done with the interface scanner, release resources.
+ *
+ * @param is handle to release
+ */
+void
+GNUNET_NT_scanner_done (struct GNUNET_NT_InterfaceScanner *is)
+{
+ if (NULL != is->interface_task)
+ {
+ GNUNET_SCHEDULER_cancel (is->interface_task);
+ is->interface_task = NULL;
+ }
+ delete_networks (is);
+ GNUNET_free (is);
+}
+
+
+/* end of nt.c */