X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fnat%2Fnat.c;h=907728fb4dd4ea452e83b2742de2457f8a8d4b71;hb=1ed484dfdf1676d92e95b9ed262abc28ca7b3aee;hp=e7c16d44ee0645bda831ef5acb9b55b5a9afa570;hpb=a0c99073d863b08a2b0a495de8c2e1ffadbce9ff;p=oweals%2Fgnunet.git diff --git a/src/nat/nat.c b/src/nat/nat.c index e7c16d44e..907728fb4 100644 --- a/src/nat/nat.c +++ b/src/nat/nat.c @@ -1,10 +1,10 @@ /* This file is part of GNUnet. - (C) 2009 Christian Grothoff (and other contributing authors) + Copyright (C) 2009, 2010, 2011 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 2, or (at your + 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 @@ -18,347 +18,1601 @@ Boston, MA 02111-1307, USA. */ -/* - * Parts of this file have been adapted from the Transmission project: - * Originally licensed by the GPL version 2. - * Copyright (C) 2007-2009 Charles Kerr - */ - /** * @file nat/nat.c * @brief Library handling UPnP and NAT-PMP port forwarding and * external IP address retrieval - * * @author Milan Bouchet-Valat + * @author Christian Grothoff */ -#include -#include -#include - -#include - #include "platform.h" -#include "gnunet_common.h" #include "gnunet_util_lib.h" +#include "gnunet_resolver_service.h" #include "gnunet_nat_lib.h" -#include "natpmp.h" -#include "upnp.h" +#include "nat.h" -/* Component name for logging */ -#define COMP_NAT _("NAT") -#define DEBUG +#define LOG(kind,...) GNUNET_log_from (kind, "nat", __VA_ARGS__) -struct GNUNET_NAT_Handle +/** + * How often do we scan for changes in our IP address from our local + * interfaces? + */ +#define IFC_SCAN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15) + +/** + * How often do we scan for changes in how our hostname resolves? + */ +#define HOSTNAME_DNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 20) + + +/** + * How often do we scan for changes in how our external (dyndns) hostname resolves? + */ +#define DYNDNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 7) + +/** + * How long until we give up trying to resolve our own hostname? + */ +#define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1) + + +/** + * Where did the given local address originate from? + * To be used for debugging as well as in the future + * to remove all addresses from a certain source when + * we reevaluate the source. + */ +enum LocalAddressSource { - int is_enabled; + /** + * Address was obtained by DNS resolution of the external hostname + * given in the configuration (i.e. hole-punched DynDNS setup). + */ + LAL_EXTERNAL_IP, + + /** + * Address was obtained by an external STUN server + */ + LAL_EXTERNAL_STUN_IP, - enum GNUNET_NAT_port_forwarding natpmp_status; - enum GNUNET_NAT_port_forwarding upnp_status; + /** + * Address was obtained by DNS resolution of the external hostname + * given in the configuration (i.e. hole-punched DynDNS setup) + * during the previous iteration (see #3213). + */ + LAL_EXTERNAL_IP_OLD, - int should_change; - u_short public_port; + /** + * Address was obtained by looking up our own hostname in DNS. + */ + LAL_HOSTNAME_DNS, - GNUNET_NAT_UPNP_Handle *upnp; - GNUNET_NAT_NATPMP_Handle *natpmp; + /** + * Address was obtained by scanning our hosts's network interfaces + * and taking their address (no DNS involved). + */ + LAL_INTERFACE_ADDRESS, - struct GNUNET_SCHEDULER_Handle *sched; - GNUNET_SCHEDULER_TaskIdentifier pulse_timer; + /** + * Addresses we were explicitly bound to. + */ + LAL_BINDTO_ADDRESS, - struct sockaddr *local_addr; /* LAN address as passed by the caller */ - struct sockaddr *ext_addr; /* External address as reported by NAT box */ - struct sockaddr *contact_addr; /* External address and port where paquets are redirected*/ - GNUNET_NAT_AddressCallback callback; - void *callback_cls; + /** + * Addresses from UPnP or PMP + */ + LAL_UPNP, + + /** + * End of the list. + */ + LAL_END }; -#ifdef DEBUG -static const char * -get_nat_state_str (int state) + +/** + * List of local addresses that we currently deem valid. Actual + * struct is followed by the 'struct sockaddr'. Note that the code + * intentionally makes no attempt to ensure that a particular address + * is only listed once (especially since it may come from different + * sources, and the source is an "internal" construct). + */ +struct LocalAddressList { - switch (state) - { - /* we're in the process of trying to set up port forwarding */ - case GNUNET_NAT_PORT_MAPPING: - return "Starting"; + /** + * This is a linked list. + */ + struct LocalAddressList *next; - /* we've successfully forwarded the port */ - case GNUNET_NAT_PORT_MAPPED: - return "Forwarded"; + /** + * Previous entry. + */ + struct LocalAddressList *prev; - /* we're cancelling the port forwarding */ - case GNUNET_NAT_PORT_UNMAPPING: - return "Stopping"; + /** + * Number of bytes of address that follow. + */ + socklen_t addrlen; - /* the port isn't forwarded */ - case GNUNET_NAT_PORT_UNMAPPED: - return "Not forwarded"; + /** + * Origin of the local address. + */ + enum LocalAddressSource source; +}; - case GNUNET_NAT_PORT_ERROR: - return "Redirection failed"; - } - return "notfound"; +/** + * Handle for miniupnp-based NAT traversal actions. + */ +struct MiniList +{ + + /** + * Doubly-linked list. + */ + struct MiniList *next; + + /** + * Doubly-linked list. + */ + struct MiniList *prev; + + /** + * Handle to mini-action. + */ + struct GNUNET_NAT_MiniHandle *mini; + + /** + * Local port number that was mapped. + */ + uint16_t port; + +}; + + +/** + * Handle for active NAT registrations. + */ +struct GNUNET_NAT_Handle +{ + + /** + * Configuration to use. + */ + const struct GNUNET_CONFIGURATION_Handle *cfg; + + /** + * Function to call when we learn about a new address. + */ + GNUNET_NAT_AddressCallback address_callback; + + /** + * Function to call when we notice another peer asking for + * connection reversal. + */ + GNUNET_NAT_ReversalCallback reversal_callback; + + /** + * Closure for callbacks (@e address_callback and @e reversal_callback) + */ + void *callback_cls; + + /** + * Handle for (DYN)DNS lookup of our external IP. + */ + struct GNUNET_RESOLVER_RequestHandle *ext_dns; + + /** + * Handle for request of hostname resolution, non-NULL if pending. + */ + struct GNUNET_RESOLVER_RequestHandle *hostname_dns; + + /** + * stdout pipe handle for the gnunet-helper-nat-server process + */ + struct GNUNET_DISK_PipeHandle *server_stdout; + + /** + * stdout file handle (for reading) for the gnunet-helper-nat-server process + */ + const struct GNUNET_DISK_FileHandle *server_stdout_handle; + + /** + * Linked list of currently valid addresses (head). + */ + struct LocalAddressList *lal_head; + + /** + * Linked list of currently valid addresses (tail). + */ + struct LocalAddressList *lal_tail; + + /** + * How long do we wait for restarting a crashed gnunet-helper-nat-server? + */ + struct GNUNET_TIME_Relative server_retry_delay; + + /** + * ID of select gnunet-helper-nat-server stdout read task + */ + struct GNUNET_SCHEDULER_Task * server_read_task; + + /** + * ID of interface IP-scan task + */ + struct GNUNET_SCHEDULER_Task * ifc_task; + + /** + * ID of hostname DNS lookup task + */ + struct GNUNET_SCHEDULER_Task * hostname_task; + + /** + * ID of DynDNS lookup task + */ + struct GNUNET_SCHEDULER_Task *dns_task; + + /** + * How often do we scan for changes in our IP address from our local + * interfaces? + */ + struct GNUNET_TIME_Relative ifc_scan_frequency; + + /** + * How often do we scan for changes in how our hostname resolves? + */ + struct GNUNET_TIME_Relative hostname_dns_frequency; + + /** + * How often do we scan for changes in how our external (dyndns) hostname resolves? + */ + struct GNUNET_TIME_Relative dyndns_frequency; + + /** + * The process id of the server process (if behind NAT) + */ + struct GNUNET_OS_Process *server_proc; + + /** + * LAN address as passed by the caller (array). + */ + struct sockaddr **local_addrs; + + /** + * Length of the @e local_addrs. + */ + socklen_t *local_addrlens; + + /** + * List of handles for UPnP-traversal, one per local port (if + * not IPv6-only). + */ + struct MiniList *mini_head; + + /** + * List of handles for UPnP-traversal, one per local port (if + * not IPv6-only). + */ + struct MiniList *mini_tail; + + /** + * Number of entries in 'local_addrs' array. + */ + unsigned int num_local_addrs; + + /** + * Our external address (according to config, UPnP may disagree...), + * in dotted decimal notation, IPv4-only. Or NULL if not known. + */ + char *external_address; + + /** + * Presumably our internal address (according to config) + */ + char *internal_address; + + /** + * Is this transport configured to be behind a NAT? + */ + int behind_nat; + + /** + * Has the NAT been punched? (according to config) + */ + int nat_punched; + + /** + * Is this transport configured to allow connections to NAT'd peers? + */ + int enable_nat_client; + + /** + * Should we run the gnunet-helper-nat-server? + */ + int enable_nat_server; + + /** + * Are we allowed to try UPnP/PMP for NAT traversal? + */ + int enable_upnp; + + /** + * Should we use local addresses (loopback)? (according to config) + */ + int use_localaddresses; + + /** + * Should we return local addresses to clients + */ + int return_localaddress; + + /** + * Should we do a DNS lookup of our hostname to find out our own IP? + */ + int use_hostname; + + /** + * Is using IPv6 disabled? + */ + int disable_ipv6; + + /** + * Is this TCP or UDP? + */ + int is_tcp; + + /** + * Port we advertise to the outside. + */ + uint16_t adv_port; + +}; + + +/** + * Try to start the gnunet-helper-nat-server (if it is not + * already running). + * + * @param h handle to NAT + */ +static void +start_gnunet_nat_server (struct GNUNET_NAT_Handle *h); + + +/** + * Remove all addresses from the list of 'local' addresses + * that originated from the given source. + * + * @param h handle to NAT + * @param src source that identifies addresses to remove + */ +static void +remove_from_address_list_by_source (struct GNUNET_NAT_Handle *h, + enum LocalAddressSource src) +{ + struct LocalAddressList *pos; + struct LocalAddressList *next; + + next = h->lal_head; + while (NULL != (pos = next)) + { + next = pos->next; + if (pos->source != src) + continue; + GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos); + if (NULL != h->address_callback) + h->address_callback (h->callback_cls, GNUNET_NO, + (const struct sockaddr *) &pos[1], pos->addrlen); + GNUNET_free (pos); + } } -#endif -static int -get_traversal_status (const struct GNUNET_NAT_Handle * s) + +/** + * Add the given address to the list of 'local' addresses, thereby + * making it a 'legal' address for this peer to have. + * + * @param h handle to NAT + * @param src where did the local address originate from? + * @param arg the address, some `struct sockaddr` + * @param arg_size number of bytes in @a arg + */ +static void +add_to_address_list_as_is (struct GNUNET_NAT_Handle *h, + enum LocalAddressSource src, + const struct sockaddr *arg, socklen_t arg_size) { - return MAX (s->natpmp_status, s->upnp_status); + struct LocalAddressList *lal; + + lal = GNUNET_malloc (sizeof (struct LocalAddressList) + arg_size); + memcpy (&lal[1], arg, arg_size); + lal->addrlen = arg_size; + lal->source = src; + GNUNET_CONTAINER_DLL_insert (h->lal_head, h->lal_tail, lal); + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Adding address `%s' from source %d\n", + GNUNET_a2s (arg, arg_size), + src); + if (NULL != h->address_callback) + h->address_callback (h->callback_cls, GNUNET_YES, arg, arg_size); } + /** - * Compare the sin(6)_addr fields of AF_INET or AF_INET(6) sockaddr. - * @param a first sockaddr - * @param b second sockaddr - * @returns 0 if addresses are equal, non-null value otherwise */ -int -GNUNET_NAT_cmp_addr (const struct sockaddr *a, const struct sockaddr *b) + * Add the given address to the list of 'local' addresses, thereby + * making it a 'legal' address for this peer to have. Set the + * port number in the process to the advertised port and possibly + * also to zero (if we have the gnunet-helper-nat-server). + * + * @param h handle to NAT + * @param src where did the local address originate from? + * @param arg the address, some `struct sockaddr` + * @param arg_size number of bytes in @a arg + */ +static void +add_to_address_list (struct GNUNET_NAT_Handle *h, + enum LocalAddressSource src, + const struct sockaddr *arg, + socklen_t arg_size) { - if (!(a && b)) - return -1; - - if (a->sa_family == AF_INET && b->sa_family == AF_INET) - return memcmp (&(((struct sockaddr_in *) a)->sin_addr), - &(((struct sockaddr_in *) b)->sin_addr), - sizeof (struct in_addr)); - else if (a->sa_family == AF_INET6 && b->sa_family == AF_INET6) - return memcmp (&(((struct sockaddr_in6 *) a)->sin6_addr), - &(((struct sockaddr_in6 *) b)->sin6_addr), - sizeof (struct in6_addr)); + struct sockaddr_in s4; + const struct sockaddr_in *in4; + struct sockaddr_in6 s6; + const struct sockaddr_in6 *in6; + + if (arg_size == sizeof (struct sockaddr_in)) + { + in4 = (const struct sockaddr_in *) arg; + s4 = *in4; + s4.sin_port = htons (h->adv_port); + add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4, + sizeof (struct sockaddr_in)); + if (GNUNET_YES == h->enable_nat_server) + { + /* also add with PORT = 0 to indicate NAT server is enabled */ + s4.sin_port = htons (0); + add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4, + sizeof (struct sockaddr_in)); + } + } + else if (arg_size == sizeof (struct sockaddr_in6)) + { + if (GNUNET_YES != h->disable_ipv6) + { + in6 = (const struct sockaddr_in6 *) arg; + s6 = *in6; + s6.sin6_port = htons (h->adv_port); + add_to_address_list_as_is (h, src, (const struct sockaddr *) &s6, + sizeof (struct sockaddr_in6)); + } + } else - return -1; + { + GNUNET_assert (0); + } } -/* Deal with a new IP address or port redirection: - * Send signals with the appropriate sockaddr (IP and port), free and changes - * or nullify the previous sockaddr. Change the port if needed. + +/** + * Add the given IP address to the list of 'local' addresses, thereby + * making it a 'legal' address for this peer to have. + * + * @param h handle to NAT + * @param src where did the local address originate from? + * @param addr the address, some `struct in_addr` or `struct in6_addr` + * @param addrlen number of bytes in addr */ static void -notify_change (struct GNUNET_NAT_Handle *nat, struct sockaddr *addr, int new_port_mapped) +add_ip_to_address_list (struct GNUNET_NAT_Handle *h, + enum LocalAddressSource src, const void *addr, + socklen_t addrlen) { - static int port_mapped = GNUNET_NO; + struct sockaddr_in s4; + const struct in_addr *in4; + struct sockaddr_in6 s6; + const struct in6_addr *in6; - /* Nothing to do. We already check in nat_pulse() that addr has changed */ - if (new_port_mapped == port_mapped) - return; + if (addrlen == sizeof (struct in_addr)) + { + in4 = (const struct in_addr *) addr; + memset (&s4, 0, sizeof (s4)); + s4.sin_family = AF_INET; + s4.sin_port = 0; +#if HAVE_SOCKADDR_IN_SIN_LEN + s4.sin_len = (u_char) sizeof (struct sockaddr_in); +#endif + s4.sin_addr = *in4; + add_to_address_list (h, src, (const struct sockaddr *) &s4, + sizeof (struct sockaddr_in)); + if (GNUNET_YES == h->enable_nat_server) + { + /* also add with PORT = 0 to indicate NAT server is enabled */ + s4.sin_port = htons (0); + add_to_address_list (h, src, (const struct sockaddr *) &s4, + sizeof (struct sockaddr_in)); - port_mapped = new_port_mapped; + } + } + else if (addrlen == sizeof (struct in6_addr)) + { + if (GNUNET_YES != h->disable_ipv6) + { + in6 = (const struct in6_addr *) addr; + memset (&s6, 0, sizeof (s6)); + s6.sin6_family = AF_INET6; + s6.sin6_port = htons (h->adv_port); +#if HAVE_SOCKADDR_IN_SIN_LEN + s6.sin6_len = (u_char) sizeof (struct sockaddr_in6); +#endif + s6.sin6_addr = *in6; + add_to_address_list (h, src, (const struct sockaddr *) &s6, + sizeof (struct sockaddr_in6)); + } + } + else + { + GNUNET_assert (0); + } +} - if (nat->contact_addr && nat->callback) - (*nat->callback) (nat->callback_cls, GNUNET_NO, (struct sockaddr *) &nat->contact_addr, - sizeof (nat->contact_addr)); - /* At this point, we're sure contact_addr has changed */ - if (nat->contact_addr) +/** + * Task to do DNS lookup on our external hostname to + * get DynDNS-IP addresses. + * + * @param cls the NAT handle + * @param tc scheduler context + */ +static void +resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); + + +/** + * Our (external) hostname was resolved and the configuration says that + * the NAT was hole-punched. + * + * @param cls the `struct GNUNET_NAT_Handle` + * @param addr NULL on error, otherwise result of DNS lookup + * @param addrlen number of bytes in @a addr + */ +static void +process_external_ip (void *cls, + const struct sockaddr *addr, + socklen_t addrlen) +{ + struct GNUNET_NAT_Handle *h = cls; + struct in_addr dummy; + + if (NULL == addr) + { + h->ext_dns = NULL; + /* Current iteration is over, remove 'old' IPs now */ + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Purging old IPs for external address\n"); + remove_from_address_list_by_source (h, LAL_EXTERNAL_IP_OLD); + if (1 == inet_pton (AF_INET, + h->external_address, + &dummy)) { - GNUNET_free (nat->contact_addr); - nat->contact_addr = NULL; + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Got numeric IP for external address, not repeating lookup\n"); + return; /* repated lookup pointless: was numeric! */ } + h->dns_task = + GNUNET_SCHEDULER_add_delayed (h->dyndns_frequency, + &resolve_dns, h); + return; + } + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Got IP `%s' for external address `%s'\n", + GNUNET_a2s (addr, addrlen), + h->external_address); + add_to_address_list (h, LAL_EXTERNAL_IP, addr, addrlen); +} - /* No address, don't signal a new one */ - if (!addr) + +/** + * Task to do a lookup on our hostname for IP addresses. + * + * @param cls the NAT handle + * @param tc scheduler context + */ +static void +resolve_hostname (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc); + + +/** + * Function called by the resolver for each address obtained from DNS + * for our own hostname. Add the addresses to the list of our IP + * addresses. + * + * @param cls closure + * @param addr one of the addresses of the host, NULL for the last address + * @param addrlen length of the @a addr + */ +static void +process_hostname_ip (void *cls, + const struct sockaddr *addr, + socklen_t addrlen) +{ + struct GNUNET_NAT_Handle *h = cls; + + if (NULL == addr) + { + h->hostname_dns = NULL; + h->hostname_task = + GNUNET_SCHEDULER_add_delayed (h->hostname_dns_frequency, + &resolve_hostname, h); + return; + } + add_to_address_list (h, LAL_HOSTNAME_DNS, addr, addrlen); +} + + +/** + * Add the IP of our network interface to the list of + * our IP addresses. + * + * @param cls the `struct GNUNET_NAT_Handle` + * @param name name of the interface + * @param isDefault do we think this may be our default interface + * @param addr address of the interface + * @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 number of bytes in @a addr and @a broadcast_addr + * @return #GNUNET_OK to continue iterating + */ +static int +process_interfaces (void *cls, const char *name, int isDefault, + const struct sockaddr *addr, + const struct sockaddr *broadcast_addr, + const struct sockaddr *netmask, socklen_t addrlen) +{ + const static struct in6_addr any6 = IN6ADDR_ANY_INIT; + struct GNUNET_NAT_Handle *h = cls; + const struct sockaddr_in *s4; + const struct sockaddr_in6 *s6; + const void *ip; + char buf[INET6_ADDRSTRLEN]; + unsigned int i; + int have_any; + + switch (addr->sa_family) + { + case AF_INET: + /* check if we're bound to the "ANY" IP address */ + have_any = GNUNET_NO; + for (i=0;inum_local_addrs;i++) + { + if (h->local_addrs[i]->sa_family != AF_INET) + continue; +#ifndef INADDR_ANY +#define INADDR_ANY 0 +#endif + if (INADDR_ANY == ((struct sockaddr_in*) h->local_addrs[i])->sin_addr.s_addr) + { + have_any = GNUNET_YES; + break; + } + } + if (GNUNET_NO == have_any) + return GNUNET_OK; /* not bound to IP 0.0.0.0 but to specific IP addresses, + do not use those from interfaces */ + s4 = (struct sockaddr_in *) addr; + ip = &s4->sin_addr; + + /* Check if address is in 127.0.0.0/8 */ + uint32_t address = ntohl ((uint32_t) (s4->sin_addr.s_addr)); + uint32_t value = (address & 0xFF000000) ^ 0x7F000000; + + if ((h->return_localaddress == GNUNET_NO) && (value == 0)) { - if (nat->ext_addr) - GNUNET_free (nat->ext_addr); - nat->ext_addr = NULL; - return; + return GNUNET_OK; } - /* Copy the new address and use it */ - else if (addr != nat->ext_addr) + if ((GNUNET_YES == h->use_localaddresses) || (value != 0)) { - if (nat->ext_addr) - GNUNET_free (nat->ext_addr); - nat->ext_addr = GNUNET_malloc (sizeof (*addr)); - memcpy (nat->ext_addr, addr, sizeof (*addr)); + add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s4->sin_addr, + sizeof (struct in_addr)); } + break; + case AF_INET6: + /* check if we're bound to the "ANY" IP address */ + have_any = GNUNET_NO; + for (i=0;inum_local_addrs;i++) + { + if (h->local_addrs[i]->sa_family != AF_INET6) + continue; + if (0 == memcmp (&any6, + &((struct sockaddr_in6*) h->local_addrs[i])->sin6_addr, + sizeof (struct in6_addr))) + { + have_any = GNUNET_YES; + break; + } + } + if (GNUNET_NO == have_any) + return GNUNET_OK; /* not bound to "ANY" IP (::0) but to specific IP addresses, + do not use those from interfaces */ - /* Recreate the ext_addr:public_port bogus address to pass to the callback */ - if (nat->ext_addr->sa_family == AF_INET) + s6 = (struct sockaddr_in6 *) addr; + if (IN6_IS_ADDR_LINKLOCAL (&((struct sockaddr_in6 *) addr)->sin6_addr)) { - struct sockaddr_in *tmp_addr; - tmp_addr = GNUNET_malloc (sizeof (struct sockaddr_in)); - tmp_addr->sin_family = AF_INET; -#ifdef HAVE_SOCKADDR_IN_SIN_LEN - tmp_addr->sin_len = sizeof (struct sockaddr_in); -#endif - tmp_addr->sin_port = port_mapped ? htons (nat->public_port) : 0; - tmp_addr->sin_addr = ((struct sockaddr_in *) nat->ext_addr)->sin_addr; - nat->contact_addr = (struct sockaddr *) tmp_addr; - if (nat->callback) - (*nat->callback) (nat->callback_cls, GNUNET_YES, nat->contact_addr, - sizeof (struct sockaddr_in)); + /* skip link local addresses */ + return GNUNET_OK; } - else if (nat->ext_addr->sa_family == AF_INET6) + if ((h->return_localaddress == GNUNET_NO) && + (IN6_IS_ADDR_LOOPBACK (&((struct sockaddr_in6 *) addr)->sin6_addr))) { - struct sockaddr_in6 *tmp_addr; - tmp_addr = GNUNET_malloc (sizeof (struct sockaddr_in6)); - tmp_addr->sin6_family = AF_INET6; -#ifdef HAVE_SOCKADDR_IN_SIN_LEN - tmp_addr->sin6_len = sizeof (struct sockaddr_in6); -#endif - tmp_addr->sin6_port = port_mapped ? htons (nat->public_port) : 0; - tmp_addr->sin6_addr = ((struct sockaddr_in6 *) nat->ext_addr)->sin6_addr; - nat->contact_addr = (struct sockaddr *) tmp_addr; - if (nat->callback) - (*nat->callback) (nat->callback_cls, GNUNET_YES, nat->contact_addr, - sizeof (struct sockaddr_in6)); + return GNUNET_OK; } + ip = &s6->sin6_addr; + if (GNUNET_YES == h->use_localaddresses) + { + add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s6->sin6_addr, + sizeof (struct in6_addr)); + } + break; + default: + GNUNET_break (0); + return GNUNET_OK; + } + if ((h->internal_address == NULL) && (h->server_proc == NULL) && + (h->server_read_task == NULL) && + (GNUNET_YES == isDefault) && ((addr->sa_family == AF_INET) || + (addr->sa_family == AF_INET6))) + { + /* no internal address configured, but we found a "default" + * interface, try using that as our 'internal' address */ + h->internal_address = + GNUNET_strdup (inet_ntop (addr->sa_family, ip, buf, sizeof (buf))); + start_gnunet_nat_server (h); + } + return GNUNET_OK; } + +/** + * Task that restarts the gnunet-helper-nat-server process after a crash + * after a certain delay. + * + * @param cls the `struct GNUNET_NAT_Handle` + * @param tc scheduler context + */ static void -nat_pulse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +restart_nat_server (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { - struct GNUNET_NAT_Handle *nat = cls; - static int first_warning = GNUNET_YES; - int old_status; - int new_status; - int port_mapped; - struct sockaddr *ext_addr_upnp = NULL; - struct sockaddr *ext_addr_natpmp = NULL; - - old_status = get_traversal_status (nat); - - /* Only update the protocol that has been successful until now */ - if (nat->upnp_status >= GNUNET_NAT_PORT_UNMAPPED) - nat->upnp_status = - GNUNET_NAT_UPNP_pulse (nat->upnp, nat->is_enabled, GNUNET_YES, - &ext_addr_upnp); - else if (nat->natpmp_status >= GNUNET_NAT_PORT_UNMAPPED) - nat->natpmp_status = - GNUNET_NAT_NATPMP_pulse (nat->natpmp, nat->is_enabled, - &ext_addr_natpmp); - else - { - nat->upnp_status = - GNUNET_NAT_UPNP_pulse (nat->upnp, nat->is_enabled, GNUNET_YES, - &ext_addr_upnp); - nat->natpmp_status = - GNUNET_NAT_NATPMP_pulse (nat->natpmp, nat->is_enabled, - &ext_addr_natpmp); - } + struct GNUNET_NAT_Handle *h = cls; - new_status = get_traversal_status (nat); + h->server_read_task = NULL; + if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) + return; + start_gnunet_nat_server (h); +} - if (old_status != new_status && - (new_status == GNUNET_NAT_PORT_UNMAPPED || new_status == GNUNET_NAT_PORT_ERROR)) - GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, COMP_NAT, - _("Port redirection failed: no UPnP or NAT-PMP routers supporting this feature found\n")); -#ifdef DEBUG - if (new_status != old_status) - GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, COMP_NAT, - _("State changed from \"%s\" to \"%s\"\n"), - get_nat_state_str (old_status), - get_nat_state_str (new_status)); -#endif +/** + * We have been notified that gnunet-helper-nat-server has written + * something to stdout. Handle the output, then reschedule this + * function to be called again once more is available. + * + * @param cls the NAT handle + * @param tc the scheduling context + */ +static void +nat_server_read (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_NAT_Handle *h = cls; + char mybuf[40]; + ssize_t bytes; + size_t i; + int port; + const char *port_start; + struct sockaddr_in sin_addr; + + h->server_read_task = NULL; + if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) + return; + memset (mybuf, 0, sizeof (mybuf)); + bytes = + GNUNET_DISK_file_read (h->server_stdout_handle, mybuf, sizeof (mybuf)); + if (bytes < 1) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Finished reading from server stdout with code: %d\n", + bytes); + if (0 != GNUNET_OS_process_kill (h->server_proc, GNUNET_TERM_SIG)) + GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill"); + GNUNET_OS_process_wait (h->server_proc); + GNUNET_OS_process_destroy (h->server_proc); + h->server_proc = NULL; + GNUNET_DISK_pipe_close (h->server_stdout); + h->server_stdout = NULL; + h->server_stdout_handle = NULL; + /* now try to restart it */ + h->server_retry_delay = GNUNET_TIME_STD_BACKOFF (h->server_retry_delay); + h->server_read_task = + GNUNET_SCHEDULER_add_delayed (h->server_retry_delay, + &restart_nat_server, h); + return; + } - port_mapped = (new_status == GNUNET_NAT_PORT_MAPPED); - if (!(ext_addr_upnp || ext_addr_natpmp)) + port_start = NULL; + for (i = 0; i < sizeof (mybuf); i++) + { + if (mybuf[i] == '\n') { - /* Address has just changed and we could not get it, or it's the first try */ - if (nat->ext_addr || first_warning) - { - GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, COMP_NAT, - _("Could not determine external IP address\n")); - first_warning = GNUNET_NO; - } - - notify_change (nat, NULL, port_mapped); + mybuf[i] = '\0'; + break; } - else if (ext_addr_upnp && GNUNET_NAT_cmp_addr (nat->ext_addr, ext_addr_upnp) != 0) + if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf))) { - GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, COMP_NAT, - _("External IP address changed from %s to %s\n"), - GNUNET_a2s (nat->ext_addr, sizeof (nat->ext_addr)), - GNUNET_a2s (ext_addr_upnp, sizeof (ext_addr_upnp))); + mybuf[i] = '\0'; + port_start = &mybuf[i + 1]; + } + } + + /* construct socket address of sender */ + memset (&sin_addr, 0, sizeof (sin_addr)); + sin_addr.sin_family = AF_INET; +#if HAVE_SOCKADDR_IN_SIN_LEN + sin_addr.sin_len = sizeof (sin_addr); +#endif + if ((NULL == port_start) || (1 != SSCANF (port_start, "%d", &port)) || + (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr))) + { + /* should we restart gnunet-helper-nat-server? */ + LOG (GNUNET_ERROR_TYPE_WARNING, "nat", + _("gnunet-helper-nat-server generated malformed address `%s'\n"), + mybuf); + h->server_read_task = + GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL, + h->server_stdout_handle, + &nat_server_read, h); + return; + } + sin_addr.sin_port = htons ((uint16_t) port); + LOG (GNUNET_ERROR_TYPE_DEBUG, "gnunet-helper-nat-server read: %s:%d\n", mybuf, + port); + h->reversal_callback (h->callback_cls, (const struct sockaddr *) &sin_addr, + sizeof (sin_addr)); + h->server_read_task = + GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL, + h->server_stdout_handle, &nat_server_read, + h); +} + + +/** + * Try to start the gnunet-helper-nat-server (if it is not + * already running). + * + * @param h handle to NAT + */ +static void +start_gnunet_nat_server (struct GNUNET_NAT_Handle *h) +{ + char *binary; - notify_change (nat, ext_addr_upnp, port_mapped); + if ((h->behind_nat == GNUNET_YES) && (h->enable_nat_server == GNUNET_YES) && + (h->internal_address != NULL) && + (NULL != + (h->server_stdout = + GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES, GNUNET_NO, GNUNET_YES)))) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Starting `%s' at `%s'\n", + "gnunet-helper-nat-server", h->internal_address); + /* Start the server process */ + binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server"); + h->server_proc = + GNUNET_OS_start_process (GNUNET_NO, 0, NULL, h->server_stdout, NULL, + binary, + "gnunet-helper-nat-server", + h->internal_address, NULL); + GNUNET_free (binary); + if (h->server_proc == NULL) + { + LOG (GNUNET_ERROR_TYPE_WARNING, "nat", _("Failed to start %s\n"), + "gnunet-helper-nat-server"); + GNUNET_DISK_pipe_close (h->server_stdout); + h->server_stdout = NULL; } - else if (ext_addr_natpmp && GNUNET_NAT_cmp_addr (nat->ext_addr, ext_addr_natpmp) != 0) + else { - GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, COMP_NAT, - _("External IP address changed from %s to %s\n"), - GNUNET_a2s (nat->ext_addr, sizeof (nat->ext_addr)), - GNUNET_a2s (ext_addr_natpmp, sizeof (ext_addr_natpmp))); - - notify_change (nat, ext_addr_natpmp, port_mapped); + /* Close the write end of the read pipe */ + GNUNET_DISK_pipe_close_end (h->server_stdout, GNUNET_DISK_PIPE_END_WRITE); + h->server_stdout_handle = + GNUNET_DISK_pipe_handle (h->server_stdout, GNUNET_DISK_PIPE_END_READ); + h->server_read_task = + GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL, + h->server_stdout_handle, + &nat_server_read, h); } + } +} + - nat->pulse_timer = GNUNET_SCHEDULER_add_delayed (nat->sched, - GNUNET_TIME_UNIT_SECONDS, - &nat_pulse, nat); +/** + * Task to scan the local network interfaces for IP addresses. + * + * @param cls the NAT handle + * @param tc scheduler context + */ +static void +list_interfaces (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_NAT_Handle *h = cls; + + h->ifc_task = NULL; + remove_from_address_list_by_source (h, LAL_INTERFACE_ADDRESS); + GNUNET_OS_network_interfaces_list (&process_interfaces, h); + h->ifc_task = + GNUNET_SCHEDULER_add_delayed (h->ifc_scan_frequency, + &list_interfaces, h); } -struct GNUNET_NAT_Handle * -GNUNET_NAT_register (struct GNUNET_SCHEDULER_Handle *sched, - const struct sockaddr *addr, socklen_t addrlen, - GNUNET_NAT_AddressCallback callback, void *callback_cls) + +/** + * Task to do a lookup on our hostname for IP addresses. + * + * @param cls the NAT handle + * @param tc scheduler context + */ +static void +resolve_hostname (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) { - struct GNUNET_NAT_Handle *nat = GNUNET_malloc (sizeof (struct GNUNET_NAT_Handle)); + struct GNUNET_NAT_Handle *h = cls; + + h->hostname_task = NULL; + remove_from_address_list_by_source (h, LAL_HOSTNAME_DNS); + h->hostname_dns = + GNUNET_RESOLVER_hostname_resolve (AF_UNSPEC, HOSTNAME_RESOLVE_TIMEOUT, + &process_hostname_ip, h); +} + - if (addr) +/** + * Task to do DNS lookup on our external hostname to + * get DynDNS-IP addresses. + * + * @param cls the NAT handle + * @param tc scheduler context + */ +static void +resolve_dns (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_NAT_Handle *h = cls; + struct LocalAddressList *pos; + + h->dns_task = NULL; + for (pos = h->lal_head; NULL != pos; pos = pos->next) + if (pos->source == LAL_EXTERNAL_IP) + pos->source = LAL_EXTERNAL_IP_OLD; + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Resolving external address `%s'\n", + h->external_address); + h->ext_dns = + GNUNET_RESOLVER_ip_get (h->external_address, AF_INET, + GNUNET_TIME_UNIT_MINUTES, + &process_external_ip, h); +} + + +/** + * Add or remove UPnP-mapped addresses. + * + * @param cls the `struct GNUNET_NAT_Handle` + * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean + * the previous (now invalid) one + * @param addr either the previous or the new public IP address + * @param addrlen actual lenght of @a addr + * @param ret GNUNET_NAT_ERROR_SUCCESS on success, otherwise an error code + */ +static void +upnp_add (void *cls, + int add_remove, + const struct sockaddr *addr, + socklen_t addrlen, + enum GNUNET_NAT_StatusCode ret) +{ + struct GNUNET_NAT_Handle *h = cls; + struct LocalAddressList *pos; + struct LocalAddressList *next; + + + if (GNUNET_NAT_ERROR_SUCCESS != ret) + { + /* Error while running upnp client */ + LOG (GNUNET_ERROR_TYPE_ERROR, + _("Error while running upnp client:\n")); + + //FIXME: convert error code to string + + return; + } + + if (GNUNET_YES == add_remove) + { + add_to_address_list (h, LAL_UPNP, addr, addrlen); + return; + } + else if (GNUNET_NO == add_remove) + { + /* remove address */ + next = h->lal_head; + while (NULL != (pos = next)) { - GNUNET_assert (addr->sa_family == AF_INET - || addr->sa_family == AF_INET6); - nat->local_addr = GNUNET_malloc (addrlen); - memcpy (nat->local_addr, addr, addrlen); - - if (addr->sa_family == AF_INET) - { - nat->public_port = ntohs (((struct sockaddr_in *) addr)->sin_port); - ((struct sockaddr_in *) nat->local_addr)->sin_port = 0; - } - else if (addr->sa_family == AF_INET6) - { - nat->public_port = ntohs (((struct sockaddr_in6 *) addr)->sin6_port); - ((struct sockaddr_in6 *) nat->local_addr)->sin6_port = 0; - } + next = pos->next; + if ((pos->source != LAL_UPNP) || (pos->addrlen != addrlen) || + (0 != memcmp (&pos[1], addr, addrlen))) + continue; + GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos); + if (NULL != h->address_callback) + h->address_callback (h->callback_cls, GNUNET_NO, + (const struct sockaddr *) &pos[1], pos->addrlen); + GNUNET_free (pos); + return; /* only remove once */ } + /* asked to remove address that does not exist */ + LOG (GNUNET_ERROR_TYPE_ERROR, + "Asked to remove unkown address `%s'\n", + GNUNET_a2s(addr, addrlen)); + GNUNET_break (0); + } else + { + + GNUNET_break (0); + } +} + + +/** + * Try to add a port mapping using UPnP. + * + * @param h overall NAT handle + * @param port port to map with UPnP + */ +static void +add_minis (struct GNUNET_NAT_Handle *h, + uint16_t port) +{ + struct MiniList *ml; + + ml = h->mini_head; + while (NULL != ml) + { + if (port == ml->port) + return; /* already got this port */ + ml = ml->next; + } + + ml = GNUNET_new (struct MiniList); + ml->port = port; + ml->mini = GNUNET_NAT_mini_map_start (port, h->is_tcp, &upnp_add, h); + + if (NULL == ml->mini) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to run upnp client for port %u\n"), ml->port); + GNUNET_free (ml); + return; + } + + GNUNET_CONTAINER_DLL_insert (h->mini_head, h->mini_tail, ml); +} + + +/** + * Task to add addresses from original bind to set of valid addrs. + * + * @param h the NAT handle + */ +static void +add_from_bind (struct GNUNET_NAT_Handle *h) +{ + static struct in6_addr any = IN6ADDR_ANY_INIT; + + unsigned int i; + struct sockaddr *sa; + const struct sockaddr_in *v4; + + for (i = 0; i < h->num_local_addrs; i++) + { + sa = h->local_addrs[i]; + switch (sa->sa_family) + { + case AF_INET: + if (sizeof (struct sockaddr_in) != h->local_addrlens[i]) + { + GNUNET_break (0); + break; + } + v4 = (const struct sockaddr_in *) sa; + if (0 != v4->sin_addr.s_addr) + add_to_address_list (h, + LAL_BINDTO_ADDRESS, sa, + sizeof (struct sockaddr_in)); + if (h->enable_upnp) + { + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Running upnp client for address `%s'\n", + GNUNET_a2s (sa,sizeof (struct sockaddr_in))); + add_minis (h, ntohs (v4->sin_port)); + } + break; + case AF_INET6: + if (sizeof (struct sockaddr_in6) != h->local_addrlens[i]) + { + GNUNET_break (0); + break; + } + if (0 != + memcmp (&((const struct sockaddr_in6 *) sa)->sin6_addr, + &any, + sizeof (struct in6_addr))) + add_to_address_list (h, + LAL_BINDTO_ADDRESS, + sa, + sizeof (struct sockaddr_in6)); + break; + default: + break; + } + } +} + + +/** + * Attempt to enable port redirection and detect public IP address contacting + * UPnP or NAT-PMP routers on the local network. Use addr to specify to which + * of the local host's addresses should the external port be mapped. The port + * is taken from the corresponding sockaddr_in[6] field. + * + * @param cfg configuration to use + * @param is_tcp #GNUNET_YES for TCP, #GNUNET_NO for UDP + * @param adv_port advertised port (port we are either bound to or that our OS + * locally performs redirection from to our bound port). + * @param num_addrs number of addresses in @a addrs + * @param addrs the local addresses packets should be redirected to + * @param addrlens actual lengths of the addresses + * @param address_callback function to call everytime the public IP address changes + * @param reversal_callback function to call if someone wants connection reversal from us + * @param callback_cls closure for callbacks + * @return NULL on error, otherwise handle that can be used to unregister + */ +struct GNUNET_NAT_Handle * +GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg, + int is_tcp, + uint16_t adv_port, + unsigned int num_addrs, + const struct sockaddr **addrs, + const socklen_t *addrlens, + GNUNET_NAT_AddressCallback address_callback, + GNUNET_NAT_ReversalCallback reversal_callback, + void *callback_cls) +{ + struct GNUNET_NAT_Handle *h; + struct in_addr in_addr; + unsigned int i; + char *binary; + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Registered with NAT service at port %u with %u IP bound local addresses\n", + (unsigned int) adv_port, num_addrs); + h = GNUNET_new (struct GNUNET_NAT_Handle); + h->server_retry_delay = GNUNET_TIME_UNIT_SECONDS; + h->cfg = cfg; + h->is_tcp = is_tcp; + h->address_callback = address_callback; + h->reversal_callback = reversal_callback; + h->callback_cls = callback_cls; + h->num_local_addrs = num_addrs; + h->adv_port = adv_port; + if (num_addrs != 0) + { + h->local_addrs = GNUNET_malloc (num_addrs * sizeof (struct sockaddr *)); + h->local_addrlens = GNUNET_malloc (num_addrs * sizeof (socklen_t)); + for (i = 0; i < num_addrs; i++) { - nat->local_addr = NULL; - nat->public_port = 0; + GNUNET_assert (addrlens[i] > 0); + GNUNET_assert (addrs[i] != NULL); + h->local_addrlens[i] = addrlens[i]; + h->local_addrs[i] = GNUNET_malloc (addrlens[i]); + memcpy (h->local_addrs[i], addrs[i], addrlens[i]); } + } + if (GNUNET_OK == + GNUNET_CONFIGURATION_have_value (cfg, "nat", "INTERNAL_ADDRESS")) + { + (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat", + "INTERNAL_ADDRESS", + &h->internal_address); + } + if ((h->internal_address != NULL) && + (inet_pton (AF_INET, h->internal_address, &in_addr) != 1)) + { + GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING, + "nat", "INTERNAL_ADDRESS", + _("malformed")); + GNUNET_free (h->internal_address); + h->internal_address = NULL; + } + + if (GNUNET_OK == + GNUNET_CONFIGURATION_have_value (cfg, "nat", "EXTERNAL_ADDRESS")) + { + (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat", + "EXTERNAL_ADDRESS", + &h->external_address); + } + h->behind_nat = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT"); + h->nat_punched = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "PUNCHED_NAT"); + h->enable_nat_client = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_CLIENT"); + h->enable_nat_server = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_SERVER"); + h->enable_upnp = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_UPNP"); + h->use_localaddresses = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_LOCALADDR"); + h->return_localaddress = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", + "RETURN_LOCAL_ADDRESSES"); + + h->use_hostname = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_HOSTNAME"); + h->disable_ipv6 = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "DISABLEV6"); + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "DYNDNS_FREQUENCY", + &h->dyndns_frequency)) + h->dyndns_frequency = DYNDNS_FREQUENCY; + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "IFC_SCAN_FREQUENCY", + &h->ifc_scan_frequency)) + h->ifc_scan_frequency = IFC_SCAN_FREQUENCY; + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "HOSTNAME_DNS_FREQUENCY", + &h->hostname_dns_frequency)) + h->hostname_dns_frequency = HOSTNAME_DNS_FREQUENCY; + + if (NULL == reversal_callback) + h->enable_nat_server = GNUNET_NO; + + /* Check for UPnP client, disable immediately if not available */ + if ( (GNUNET_YES == h->enable_upnp) && + (GNUNET_SYSERR == + GNUNET_OS_check_helper_binary ("upnpc", GNUNET_NO, NULL)) ) + { + LOG (GNUNET_ERROR_TYPE_ERROR, + _("UPnP enabled in configuration, but UPnP client `upnpc` command not found, disabling UPnP \n")); + h->enable_upnp = GNUNET_NO; + } + + /* Check if NAT was hole-punched */ + if ((NULL != h->address_callback) && + (NULL != h->external_address) && + (GNUNET_YES == h->nat_punched)) + { + h->dns_task = GNUNET_SCHEDULER_add_now (&resolve_dns, h); + h->enable_nat_server = GNUNET_NO; + h->enable_upnp = GNUNET_NO; + } + else + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "No external IP address given to add to our list of addresses\n"); + } + + /* Test for SUID binaries */ + binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server"); + if ((h->behind_nat == GNUNET_YES) && (GNUNET_YES == h->enable_nat_server) && + (GNUNET_YES != + GNUNET_OS_check_helper_binary (binary, GNUNET_YES, "-d 127.0.0.1" ))) // use localhost as source for that one udp-port, ok for testing + { + h->enable_nat_server = GNUNET_NO; + LOG (GNUNET_ERROR_TYPE_WARNING, + _("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"), + "gnunet-helper-nat-server"); + } + GNUNET_free (binary); + binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client"); + if ((GNUNET_YES == h->enable_nat_client) && + (GNUNET_YES != + GNUNET_OS_check_helper_binary (binary, GNUNET_YES, "-d 127.0.0.1 127.0.0.2 42"))) // none of these parameters are actually used in privilege testing mode + { + h->enable_nat_client = GNUNET_NO; + LOG (GNUNET_ERROR_TYPE_WARNING, + _ + ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"), + "gnunet-helper-nat-client"); + } + GNUNET_free (binary); + start_gnunet_nat_server (h); + + /* FIXME: add support for UPnP, etc */ - nat->should_change = GNUNET_YES; - nat->sched = sched; - nat->is_enabled = GNUNET_YES; - nat->upnp_status = GNUNET_NAT_PORT_UNMAPPED; - nat->natpmp_status = GNUNET_NAT_PORT_UNMAPPED; - nat->callback = callback; - nat->callback_cls = callback_cls; - nat->ext_addr = NULL; - nat->contact_addr = NULL; - nat->natpmp = GNUNET_NAT_NATPMP_init (nat->local_addr, addrlen, nat->public_port); - nat->upnp = GNUNET_NAT_UPNP_init (nat->local_addr, addrlen, nat->public_port); - - nat->pulse_timer = GNUNET_SCHEDULER_add_delayed (sched, - GNUNET_TIME_UNIT_SECONDS, - &nat_pulse, nat); - - return nat; + if (NULL != h->address_callback) + { + h->ifc_task = GNUNET_SCHEDULER_add_now (&list_interfaces, + h); + if (GNUNET_YES == h->use_hostname) + h->hostname_task = GNUNET_SCHEDULER_add_now (&resolve_hostname, + h); + } + add_from_bind (h); + + return h; } + +/** + * Stop port redirection and public IP address detection for the given handle. + * This frees the handle, after having sent the needed commands to close open ports. + * + * @param h the handle to stop + */ void -GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *nat) +GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h) +{ + unsigned int i; + struct LocalAddressList *lal; + struct MiniList *ml; + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "NAT unregister called\n"); + while (NULL != (ml = h->mini_head)) + { + GNUNET_CONTAINER_DLL_remove (h->mini_head, + h->mini_tail, + ml); + if (NULL != ml->mini) + GNUNET_NAT_mini_map_stop (ml->mini); + GNUNET_free (ml); + } + if (NULL != h->ext_dns) + { + GNUNET_RESOLVER_request_cancel (h->ext_dns); + h->ext_dns = NULL; + } + if (NULL != h->hostname_dns) + { + GNUNET_RESOLVER_request_cancel (h->hostname_dns); + h->hostname_dns = NULL; + } + if (NULL != h->server_read_task) + { + GNUNET_SCHEDULER_cancel (h->server_read_task); + h->server_read_task = NULL; + } + if (NULL != h->ifc_task) + { + GNUNET_SCHEDULER_cancel (h->ifc_task); + h->ifc_task = NULL; + } + if (NULL != h->hostname_task) + { + GNUNET_SCHEDULER_cancel (h->hostname_task); + h->hostname_task = NULL; + } + if (NULL != h->dns_task) + { + GNUNET_SCHEDULER_cancel (h->dns_task); + h->dns_task = NULL; + } + if (NULL != h->server_proc) + { + if (0 != GNUNET_OS_process_kill (h->server_proc, GNUNET_TERM_SIG)) + GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill"); + GNUNET_OS_process_wait (h->server_proc); + GNUNET_OS_process_destroy (h->server_proc); + h->server_proc = NULL; + GNUNET_DISK_pipe_close (h->server_stdout); + h->server_stdout = NULL; + h->server_stdout_handle = NULL; + } + if (NULL != h->server_stdout) + { + GNUNET_DISK_pipe_close (h->server_stdout); + h->server_stdout = NULL; + h->server_stdout_handle = NULL; + } + while (NULL != (lal = h->lal_head)) + { + GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, lal); + if (NULL != h->address_callback) + h->address_callback (h->callback_cls, GNUNET_NO, + (const struct sockaddr *) &lal[1], lal->addrlen); + GNUNET_free (lal); + } + for (i = 0; i < h->num_local_addrs; i++) + GNUNET_free (h->local_addrs[i]); + GNUNET_free_non_null (h->local_addrs); + GNUNET_free_non_null (h->local_addrlens); + GNUNET_free_non_null (h->external_address); + GNUNET_free_non_null (h->internal_address); + GNUNET_free (h); +} + + +/** + * We learned about a peer (possibly behind NAT) so run the + * gnunet-helper-nat-client to send dummy ICMP responses to cause + * that peer to connect to us (connection reversal). + * + * @param h handle (used for configuration) + * @param sa the address of the peer (IPv4-only) + * @return #GNUNET_SYSERR on error, #GNUNET_NO if nat client is disabled, + * #GNUNET_OK otherwise + */ +int +GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h, + const struct sockaddr_in *sa) + + +{ + char inet4[INET_ADDRSTRLEN]; + char port_as_string[6]; + struct GNUNET_OS_Process *proc; + char *binary; + + if (GNUNET_YES != h->enable_nat_client) + return GNUNET_NO; /* not permitted / possible */ + + if (h->internal_address == NULL) + { + LOG (GNUNET_ERROR_TYPE_WARNING, "nat", + _("Internal IP address not known, cannot use ICMP NAT traversal method\n")); + return GNUNET_SYSERR; + } + GNUNET_assert (sa->sin_family == AF_INET); + if (NULL == inet_ntop (AF_INET, &sa->sin_addr, inet4, INET_ADDRSTRLEN)) + { + GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, + "nat", + "inet_ntop"); + return GNUNET_SYSERR; + } + GNUNET_snprintf (port_as_string, + sizeof (port_as_string), + "%d", + h->adv_port); + LOG (GNUNET_ERROR_TYPE_DEBUG, + _("Running gnunet-helper-nat-client %s %s %u\n"), + h->internal_address, + inet4, + (unsigned int) h->adv_port); + binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client"); + proc = + GNUNET_OS_start_process (GNUNET_NO, 0, NULL, NULL, NULL, + binary, + "gnunet-helper-nat-client", + h->internal_address, + inet4, port_as_string, NULL); + GNUNET_free (binary); + if (NULL == proc) + return GNUNET_SYSERR; + /* we know that the gnunet-helper-nat-client will terminate virtually + * instantly */ + GNUNET_OS_process_wait (proc); + GNUNET_OS_process_destroy (proc); + return GNUNET_OK; +} + + +/** + * Test if the given address is (currently) a plausible IP address for this peer. + * + * @param h the handle returned by register + * @param addr IP address to test (IPv4 or IPv6) + * @param addrlen number of bytes in @a addr + * @return #GNUNET_YES if the address is plausible, + * #GNUNET_NO if the address is not plausible, + * #GNUNET_SYSERR if the address is malformed + */ +int +GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h, + const void *addr, + socklen_t addrlen) +{ + struct LocalAddressList *pos; + const struct sockaddr_in *in4; + const struct sockaddr_in6 *in6; + + if ((addrlen != sizeof (struct in_addr)) && + (addrlen != sizeof (struct in6_addr))) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + for (pos = h->lal_head; NULL != pos; pos = pos->next) + { + if (pos->addrlen == sizeof (struct sockaddr_in)) + { + in4 = (struct sockaddr_in *) &pos[1]; + if ((addrlen == sizeof (struct in_addr)) && + (0 == memcmp (&in4->sin_addr, addr, sizeof (struct in_addr)))) + return GNUNET_YES; + } + else if (pos->addrlen == sizeof (struct sockaddr_in6)) + { + in6 = (struct sockaddr_in6 *) &pos[1]; + if ((addrlen == sizeof (struct in6_addr)) && + (0 == memcmp (&in6->sin6_addr, addr, sizeof (struct in6_addr)))) + return GNUNET_YES; + } + else + { + GNUNET_assert (0); + } + } + LOG (GNUNET_ERROR_TYPE_WARNING, + "Asked to validate one of my addresses and validation failed!\n"); + return GNUNET_NO; +} + +/** + * Converts enum GNUNET_NAT_StatusCode to a string + * + * @param err error code to resolve to a string + * @return pointer to a static string containing the error code + */ +const char * +GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err) { - struct sockaddr *addr; - GNUNET_SCHEDULER_cancel (nat->sched, nat->pulse_timer); - - nat->upnp_status = - GNUNET_NAT_UPNP_pulse (nat->upnp, GNUNET_NO, GNUNET_NO, - &addr); - nat->natpmp_status = - GNUNET_NAT_NATPMP_pulse (nat->natpmp, GNUNET_NO, - &addr); - - GNUNET_NAT_NATPMP_close (nat->natpmp); - GNUNET_NAT_UPNP_close (nat->upnp); - - if (nat->local_addr) - GNUNET_free (nat->local_addr); - if (nat->ext_addr) - GNUNET_free (nat->ext_addr); - GNUNET_free (nat); + switch (err) + { + case GNUNET_NAT_ERROR_SUCCESS: + return _ ("Operation Successful"); + case GNUNET_NAT_ERROR_IPC_FAILURE: + return _ ("Internal Failure (IPC, ...)"); + case GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR: + return _ ("Failure in network subsystem, check permissions."); + case GNUNET_NAT_ERROR_TIMEOUT: + return _ ("Encountered timeout while performing operation"); + case GNUNET_NAT_ERROR_NOT_ONLINE: + return _ ("detected that we are offline"); + case GNUNET_NAT_ERROR_UPNPC_NOT_FOUND: + return _ ("`upnpc` command not found"); + case GNUNET_NAT_ERROR_UPNPC_FAILED: + return _ ("Failed to run `upnpc` command"); + case GNUNET_NAT_ERROR_UPNPC_TIMEOUT: + return _ ("`upnpc' command took too long, process killed"); + case GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED: + return _ ("`upnpc' command failed to establish port mapping"); + case GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND: + return _ ("`external-ip' command not found"); + case GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED: + return _ ("Failed to run `external-ip` command"); + case GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID: + return _ ("`external-ip' command output invalid"); + case GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID: + return _ ("no valid address was returned by `external-ip'"); + case GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO: + return _ ("Could not determine interface with internal/local network address"); + case GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND: + return _ ("No functioning gnunet-helper-nat-server installation found"); + case GNUNET_NAT_ERROR_NAT_TEST_START_FAILED: + return _ ("NAT test could not be initialized"); + case GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT: + return _ ("NAT test timeout reached"); + case GNUNET_NAT_ERROR_NAT_REGISTER_FAILED: + return _ ("could not register NAT"); + case GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND: + return _ ("No working gnunet-helper-nat-client installation found"); +/* case: + return _ ("");*/ + default: + return "unknown status code"; + } } + +/* end of nat.c */