/* This file is part of GNUnet. Copyright (C) 2009, 2015 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 . SPDX-License-Identifier: AGPL3.0-or-later */ /** * @file hello/hello.c * @brief helper library for handling HELLOs * @author Christian Grothoff * @author Matthias Wachs */ #include "platform.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_util_lib.h" #include "gnunet_transport_plugin.h" /** * Context used for building our own URI. */ struct GNUNET_HELLO_ComposeUriContext { /** * Final URI. */ char *uri; /** * Function for finding transport plugins by name. */ GNUNET_HELLO_TransportPluginsFind plugins_find; }; /** * Context for #add_address_to_hello(). */ struct GNUNET_HELLO_ParseUriContext { /** * Position in the URI with the next address to parse. */ const char *pos; /** * Set to #GNUNET_SYSERR to indicate parse errors. */ int ret; /** * Counter */ unsigned int counter_total; /** * Counter skipped addresses */ unsigned int counter_added; /** * Function for finding transport plugins by name. */ GNUNET_HELLO_TransportPluginsFind plugins_find; }; /** * Return HELLO type * * @param h HELLO Message to test * @return #GNUNET_YES for friend-only or #GNUNET_NO otherwise */ int GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h) { if (GNUNET_YES == ntohl (h->friend_only)) return GNUNET_YES; return GNUNET_NO; } /** * Copy the given address information into * the given buffer using the format of HELLOs. * * @param address the address * @param expiration expiration for the @a address * @param target where to copy the @a address * @param max maximum number of bytes to copy to target * @return number of bytes copied, 0 if * the target buffer was not big enough. */ size_t GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration, char *target, size_t max) { uint16_t alen; size_t slen; struct GNUNET_TIME_AbsoluteNBO exp; slen = strlen (address->transport_name) + 1; if (slen + sizeof(uint16_t) + sizeof(struct GNUNET_TIME_AbsoluteNBO) + address->address_length > max) return 0; exp = GNUNET_TIME_absolute_hton (expiration); alen = htons ((uint16_t) address->address_length); GNUNET_memcpy (target, address->transport_name, slen); GNUNET_memcpy (&target[slen], &alen, sizeof(uint16_t)); slen += sizeof(uint16_t); GNUNET_memcpy (&target[slen], &exp, sizeof(struct GNUNET_TIME_AbsoluteNBO)); slen += sizeof(struct GNUNET_TIME_AbsoluteNBO); GNUNET_memcpy (&target[slen], address->address, address->address_length); slen += address->address_length; return slen; } /** * Get the size of an address entry in a HELLO message. * * @param buf pointer to the start of the address entry * @param max maximum size of the entry (end of @a buf) * @param ralen set to the address length * @return size of the entry, or 0 if @a max is not large enough */ static size_t get_hello_address_size (const char *buf, size_t max, uint16_t *ralen) { const char *pos; uint16_t alen; size_t left; size_t slen; left = max; pos = buf; slen = 1; while ((left > 0) && ('\0' != *pos)) { left--; pos++; slen++; } if (0 == left) { /* 0-termination not found */ GNUNET_break_op (0); return 0; } pos++; if (left < sizeof(uint16_t) + sizeof(struct GNUNET_TIME_AbsoluteNBO)) { /* not enough space for addrlen */ GNUNET_break_op (0); return 0; } GNUNET_memcpy (&alen, pos, sizeof(uint16_t)); alen = ntohs (alen); *ralen = alen; slen += alen + sizeof(uint16_t) + sizeof(struct GNUNET_TIME_AbsoluteNBO); if (max < slen) { /* not enough space for addr */ GNUNET_break_op (0); return 0; } return slen; } /** * Construct a HELLO message given the public key, * expiration time and an iterator that spews the * transport addresses. * * If friend only is set to #GNUNET_YES we create a FRIEND_HELLO which * will not be gossiped to other peers. * * @param public_key public key to include in the HELLO * @param addrgen callback to invoke to get addresses * @param addrgen_cls closure for @a addrgen * @param friend_only should the returned HELLO be only visible to friends? * @return the hello message */ struct GNUNET_HELLO_Message * GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *public_key, GNUNET_HELLO_GenerateAddressListCallback addrgen, void *addrgen_cls, int friend_only) { char buffer[GNUNET_MAX_MESSAGE_SIZE - 1 - 256 - sizeof(struct GNUNET_HELLO_Message)]; size_t max; size_t used; size_t ret; struct GNUNET_HELLO_Message *hello; GNUNET_assert (NULL != public_key); GNUNET_assert ((GNUNET_YES == friend_only) || (GNUNET_NO == friend_only)); max = sizeof(buffer); used = 0; if (NULL != addrgen) { while (GNUNET_SYSERR != (ret = addrgen (addrgen_cls, max, &buffer[used]))) { max -= ret; used += ret; } } hello = GNUNET_malloc (sizeof(struct GNUNET_HELLO_Message) + used); hello->header.type = htons (GNUNET_MESSAGE_TYPE_HELLO); hello->header.size = htons (sizeof(struct GNUNET_HELLO_Message) + used); hello->friend_only = htonl (friend_only); hello->publicKey = *public_key; GNUNET_memcpy (&hello[1], buffer, used); return hello; } /** * Iterate over all of the addresses in the HELLO. * * @param msg HELLO to iterate over * @param return_modified if a modified copy should be returned, * otherwise NULL will be returned * @param it iterator to call on each address * @param it_cls closure for @a it * @return modified HELLO message */ struct GNUNET_HELLO_Message * GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg, int return_modified, GNUNET_HELLO_AddressIterator it, void *it_cls) { struct GNUNET_HELLO_Address address; uint16_t msize; struct GNUNET_HELLO_Message *ret; const char *inptr; size_t insize; size_t esize; size_t wpos; char *woff; uint16_t alen; struct GNUNET_TIME_AbsoluteNBO expire; int iret; msize = GNUNET_HELLO_size (msg); if ((msize < sizeof(struct GNUNET_HELLO_Message)) || (ntohs (msg->header.type) != GNUNET_MESSAGE_TYPE_HELLO)) { GNUNET_break_op (0); return NULL; } ret = NULL; if (return_modified) { ret = GNUNET_malloc (msize); GNUNET_memcpy (ret, msg, msize); } inptr = (const char *) &msg[1]; insize = msize - sizeof(struct GNUNET_HELLO_Message); wpos = 0; woff = (NULL != ret) ? (char *) &ret[1] : NULL; address.peer.public_key = msg->publicKey; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "HELLO has %u bytes of address data\n", (unsigned int) insize); while (insize > 0) { esize = get_hello_address_size (inptr, insize, &alen); if (0 == esize) { GNUNET_break (0); GNUNET_free_non_null (ret); return NULL; } /* need GNUNET_memcpy() due to possibility of misalignment */ GNUNET_memcpy (&expire, &inptr[esize - alen - sizeof(struct GNUNET_TIME_AbsoluteNBO)], sizeof(struct GNUNET_TIME_AbsoluteNBO)); address.address = &inptr[esize - alen]; address.address_length = alen; address.transport_name = inptr; address.local_info = GNUNET_HELLO_ADDRESS_INFO_NONE; iret = it (it_cls, &address, GNUNET_TIME_absolute_ntoh (expire)); if (GNUNET_SYSERR == iret) break; if ((GNUNET_OK == iret) && (NULL != ret)) { /* copy address over */ GNUNET_memcpy (woff, inptr, esize); woff += esize; wpos += esize; } insize -= esize; inptr += esize; } if (NULL != ret) ret->header.size = ntohs (sizeof(struct GNUNET_HELLO_Message) + wpos); return ret; } /** * Closure for #get_match_exp(). */ struct ExpireContext { /** * Address we are looking for. */ const struct GNUNET_HELLO_Address *address; /** * Set to #GNUNET_YES if we found the @e address. */ int found; /** * Set to the expiration of the match if @e found is #GNUNET_YES. */ struct GNUNET_TIME_Absolute expiration; }; /** * Store the expiration time of an address that matches the template. * * @param cls the `struct ExpireContext` * @param address address to match against the template * @param expiration expiration time of @a address, to store in @a cls * @return #GNUNET_SYSERR if we found a matching address, #GNUNET_OK otherwise */ static int get_match_exp (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct ExpireContext *ec = cls; if (0 != GNUNET_HELLO_address_cmp (address, ec->address)) return GNUNET_OK; ec->found = GNUNET_YES; ec->expiration = expiration; return GNUNET_SYSERR; /* done here */ } /** * Context for a #GNUNET_HELLO_Merge operation. */ struct MergeContext { /** * First HELLO we are merging. */ const struct GNUNET_HELLO_Message *h1; /** * Second HELLO we are merging. */ const struct GNUNET_HELLO_Message *h2; /** * Either @e h1 or @e h2, used when copying * to compare against (so we only copy the * most recent entry). */ const struct GNUNET_HELLO_Message *other; /** * Buffer where we copy to. */ char *buf; /** * Number of bytes allocated in @e buf */ size_t max; /** * Current (write) offset in @e buf. */ size_t ret; /** * Should we copy addresses with an identical value * and expiration time in @e other, or do we only * copy addresses with strictly later expiration times? */ int take_equal; }; /** * Append the address @a address to the buffer from * the merge context IF it is more recent than equivalent * addresses in `other`. * * @param cls the `struct MergeContext` * @param address the HELLO address we might copy * @param expiration expiration time for @a address * @return always #GNUNET_OK */ static int copy_latest (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct MergeContext *mc = cls; struct ExpireContext ec; ec.address = address; ec.found = GNUNET_NO; /* check if address exists in other */ GNUNET_HELLO_iterate_addresses (mc->other, GNUNET_NO, &get_match_exp, &ec); if ((GNUNET_NO == ec.found) || (ec.expiration.abs_value_us < expiration.abs_value_us) || ((ec.expiration.abs_value_us == expiration.abs_value_us) && (GNUNET_YES == mc->take_equal))) { /* copy address to buffer */ mc->ret += GNUNET_HELLO_add_address (address, expiration, &mc->buf[mc->ret], mc->max - mc->ret); } return GNUNET_OK; } /** * Function called to build the HELLO during * #GNUNET_HELLO_merge() by merging addresses from * two original HELLOs. * * @param cls the `struct MergeContext` * @param max number of bytes we can write at most in @a buf * @param buf where to copy the addresses * @return #GNUNET_SYSERR to end iteration, otherwise number of bytes written to @a buf */ static ssize_t merge_addr (void *cls, size_t max, void *buf) { struct MergeContext *mc = cls; if (NULL == mc->h1) return GNUNET_SYSERR; /* Stop iteration */ mc->ret = 0; mc->max = max; mc->buf = buf; mc->take_equal = GNUNET_NO; mc->other = mc->h2; /* copy addresses from h1, if strictly larger expiration than h2 */ GNUNET_HELLO_iterate_addresses (mc->h1, GNUNET_NO, ©_latest, mc); mc->take_equal = GNUNET_YES; mc->other = mc->h1; /* copy addresses from h2, if larger or equal expiration than h1 */ GNUNET_HELLO_iterate_addresses (mc->h2, GNUNET_NO, ©_latest, mc); /* set marker to stop iteration */ mc->h1 = NULL; return mc->ret; } /** * Construct a HELLO message by merging the * addresses in two existing HELLOs (which * must be for the same peer). * * @param h1 first HELLO message * @param h2 the second HELLO message * @return the combined HELLO message */ struct GNUNET_HELLO_Message * GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1, const struct GNUNET_HELLO_Message *h2) { struct MergeContext mc = { h1, h2, NULL, NULL, 0, 0, 0 }; int friend_only; if (h1->friend_only != h2->friend_only) friend_only = GNUNET_YES; /* One of the HELLOs is friend only */ else friend_only = ntohl (h1->friend_only); /* Both HELLO's have the same type */ return GNUNET_HELLO_create (&h1->publicKey, &merge_addr, &mc, friend_only); } /** * Context used in #GNUNET_HELLO_iterate_new_addresses() to * figure out which addresses are in fact 'new'. */ struct DeltaContext { /** * We should ignore addresses that expire before this time. */ struct GNUNET_TIME_Absolute expiration_limit; /** * Function to call on addresses that are indeed new. */ GNUNET_HELLO_AddressIterator it; /** * Closure for @e it. */ void *it_cls; /** * HELLO with known addresses, addresses in this HELLO * we must always ignore. */ const struct GNUNET_HELLO_Message *old_hello; }; /** * Check if the given address is 'new', and if so, call * the iterator. Compares the existing address against * addresses in the context's `old_hello` and calls the * iterator on those that are new (and not expired). * * @param cls the `struct DeltaContext` * @param address an address to check whether it is new * @param expiration expiration time for @a address * @return #GNUNET_YES if the address is ignored, otherwise * whatever the iterator returned. */ static int delta_match (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct DeltaContext *dc = cls; int ret; struct ExpireContext ec; ec.address = address; ec.found = GNUNET_NO; GNUNET_HELLO_iterate_addresses (dc->old_hello, GNUNET_NO, &get_match_exp, &ec); if ((GNUNET_YES == ec.found) && ((ec.expiration.abs_value_us > expiration.abs_value_us) || (ec.expiration.abs_value_us >= dc->expiration_limit.abs_value_us))) return GNUNET_YES; /* skip: found and boring */ ret = dc->it (dc->it_cls, address, expiration); return ret; } /** * Iterate over addresses in @a new_hello that are NOT already present * in @a old_hello. Note that if the address is present in @a old_hello * but the expiration time in @a new_hello is more recent, the iterator * is also called. * * @param new_hello a HELLO message * @param old_hello a HELLO message * @param expiration_limit ignore addresses in @a old_hello * that expired before the given time stamp * @param it iterator to call on each address * @param it_cls closure for @a it */ void GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message *new_hello, const struct GNUNET_HELLO_Message *old_hello, struct GNUNET_TIME_Absolute expiration_limit, GNUNET_HELLO_AddressIterator it, void *it_cls) { struct DeltaContext dc; dc.expiration_limit = expiration_limit; dc.it = it; dc.it_cls = it_cls; dc.old_hello = old_hello; GNUNET_assert (NULL == GNUNET_HELLO_iterate_addresses (new_hello, GNUNET_NO, &delta_match, &dc)); } /** * Return the size of the given HELLO message. * @param hello to inspect * @return the size, 0 if HELLO is invalid */ uint16_t GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello) { uint16_t ret = ntohs (hello->header.size); if ((ret < sizeof(struct GNUNET_HELLO_Message)) || (ntohs (hello->header.type) != GNUNET_MESSAGE_TYPE_HELLO)) return 0; return ret; } /** * Get the peer identity from a HELLO message. * * @param hello the hello message * @param peer where to store the peer's identity * @return #GNUNET_SYSERR if the HELLO was malformed */ int GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello, struct GNUNET_PeerIdentity *peer) { uint16_t ret = ntohs (hello->header.size); if ((ret < sizeof(struct GNUNET_HELLO_Message)) || (ntohs (hello->header.type) != GNUNET_MESSAGE_TYPE_HELLO)) return GNUNET_SYSERR; peer->public_key = hello->publicKey; return GNUNET_OK; } /** * Get the header from a HELLO message, used so other code * can correctly send HELLO messages. * * @param hello the hello message * * @return header or NULL if the HELLO was malformed */ struct GNUNET_MessageHeader * GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello) { uint16_t ret = ntohs (hello->header.size); if ((ret < sizeof(struct GNUNET_HELLO_Message)) || (ntohs (hello->header.type) != GNUNET_MESSAGE_TYPE_HELLO)) return NULL; return &hello->header; } /** * Context used for comparing HELLOs in #GNUNET_HELLO_equals(). */ struct EqualsContext { /** * Addresses that expired before this date are ignored for * the comparisson. */ struct GNUNET_TIME_Absolute expiration_limit; /** * Earliest expiration time for which we found a match * with a difference in expiration times. * At this time, the two HELLOs may start to diverge. */ struct GNUNET_TIME_Absolute result; /** * HELLO message to compare against. (First set to the second * HELLO, then set to the first HELLO.) */ const struct GNUNET_HELLO_Message *ref; /** * Address we are currently looking for. */ const struct GNUNET_HELLO_Address *address; /** * Expiration time of @e address. */ struct GNUNET_TIME_Absolute expiration; /** * Did we find the address we were looking for? */ int found; }; /** * Check if the given address matches the address we are currently * looking for. If so, sets `found` to #GNUNET_YES and, if the * expiration times for the two addresses differ, updates `result` to * the minimum of our @a expiration and the existing value * * @param cls the `struct EqualsContext` * @param address address from the reference HELLO * @param expiration expiration time for @a address * @return #GNUNET_YES if the address is expired or does not match * #GNUNET_SYSERR if the address does match. */ static int find_other_matching (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct EqualsContext *ec = cls; if (expiration.abs_value_us < ec->expiration_limit.abs_value_us) return GNUNET_YES; if (0 == GNUNET_HELLO_address_cmp (address, ec->address)) { ec->found = GNUNET_YES; if (expiration.abs_value_us < ec->expiration.abs_value_us) ec->result = GNUNET_TIME_absolute_min (expiration, ec->result); return GNUNET_SYSERR; } return GNUNET_YES; } /** * Helper function for #GNUNET_HELLO_equals(). Checks * if the given @a address exists also in the other HELLO; * if not, the result time is set to zero and the iteration * is aborted. * * @param cls the `struct EqualsContext` * @param address address to locate * @param expiration expiration time of the current address * @return #GNUNET_OK if the address exists or is expired, * #GNUNET_SYSERR if it was not found */ static int find_matching (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct EqualsContext *ec = cls; if (expiration.abs_value_us < ec->expiration_limit.abs_value_us) return GNUNET_OK; /* expired, we don't care */ ec->address = address; ec->expiration = expiration; ec->found = GNUNET_NO; GNUNET_HELLO_iterate_addresses (ec->ref, GNUNET_NO, &find_other_matching, ec); if (GNUNET_NO == ec->found) { /* not found, we differ *now* */ ec->result = GNUNET_TIME_UNIT_ZERO_ABS; return GNUNET_SYSERR; } return GNUNET_OK; } /** * Test if two HELLO messages contain the same addresses. * If they only differ in expiration time, the lowest * expiration time larger than @a now where they differ * is returned. * * @param h1 first HELLO message * @param h2 the second HELLO message * @param now time to use for deciding which addresses have * expired and should not be considered at all * @return absolute time forever if the two HELLOs are * totally identical; smallest timestamp >= @a now if * they only differ in timestamps; * zero if the some addresses with expirations >= @a now * do not match at all */ struct GNUNET_TIME_Absolute GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1, const struct GNUNET_HELLO_Message *h2, struct GNUNET_TIME_Absolute now) { struct EqualsContext ec; if (h1->header.type != h2->header.type) return GNUNET_TIME_UNIT_ZERO_ABS; if (0 != GNUNET_memcmp (&h1->publicKey, &h2->publicKey)) return GNUNET_TIME_UNIT_ZERO_ABS; ec.expiration_limit = now; ec.result = GNUNET_TIME_UNIT_FOREVER_ABS; ec.ref = h2; GNUNET_HELLO_iterate_addresses (h1, GNUNET_NO, &find_matching, &ec); if (ec.result.abs_value_us == GNUNET_TIME_UNIT_ZERO.rel_value_us) return ec.result; ec.ref = h1; GNUNET_HELLO_iterate_addresses (h2, GNUNET_NO, &find_matching, &ec); return ec.result; } /** * Iterator to find the time when the last address will expire. * Updates the maximum value stored in @a cls. * * @param cls where to store the max, a `struct GNUNET_TIME_Absolute` * @param address an address (ignored) * @param expiration expiration time for @a address * @return #GNUNET_OK (always) */ static int find_max_expire (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct GNUNET_TIME_Absolute *max = cls; *max = GNUNET_TIME_absolute_max (*max, expiration); return GNUNET_OK; } /** * When does the last address in the given HELLO expire? * * @param msg HELLO to inspect * @return time the last address expires, 0 if there are no addresses in the HELLO */ struct GNUNET_TIME_Absolute GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg) { struct GNUNET_TIME_Absolute ret; ret = GNUNET_TIME_UNIT_ZERO_ABS; GNUNET_HELLO_iterate_addresses (msg, GNUNET_NO, &find_max_expire, &ret); return ret; } /** * GNUnet URIs are of the general form "gnunet://MODULE/IDENTIFIER". * The specific structure of "IDENTIFIER" depends on the module and * maybe differenciated into additional subcategories if applicable. * This module only deals with hello identifiers (MODULE = "hello"). *

* * The concrete URI format is: * * "gnunet://hello/PEER[+YYYYMMDDHHMMSS++

]...". * These URIs can be used to add a peer record to peerinfo service. * PEER is the string representation of peer's public key. * YYYYMMDDHHMMSS is the expiration date. * TYPE is a transport type. * ADDRESS is the address, its format depends upon the transport type. * The concrete transport types and corresponding address formats are: * * * * The encoding for hexadecimal values is defined in the crypto_hash.c * module in the gnunetutil library and discussed there. * * Examples: * * gnunet://hello/V8XXK9GAN5ZJFRFQP8MQX3D83BZTSBQVHKWWD0JPE63Z821906EG+20120302010059+TCP+192.168.0.1:2086+TCP+64.23.8.174:0 * gnunet://hello/V8XXK9GAN5ZJFRFQP8MQX3D83BZTSBQVHKWWD0JPE63Z821906EG+20120302010059+TCP+[2001:db8:85a3:8d3:1319:8a2e:370:7348]:2086 * *

*/ /** * Function that is called on each address of this peer. * Expands the corresponding URI string. * * @param cls the `struct GNUNET_HELLO_ComposeUriContext` * @param address address to add * @param expiration expiration time for the address * @return #GNUNET_OK (continue iteration). */ static int add_address_to_uri (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct GNUNET_HELLO_ComposeUriContext *ctx = cls; struct GNUNET_TRANSPORT_PluginFunctions *papi; const char *addr; char *ret; char *addr_dup; char *pos; char tbuf[16] = ""; char *client_str = "_client"; struct tm *t; time_t seconds; papi = ctx->plugins_find (address->transport_name); if (NULL == papi) { /* Not an error - we might just not have the right plugin. */ return GNUNET_OK; } if (NULL == papi->address_to_string) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "URI conversion not implemented for plugin `%s'\n", address->transport_name); return GNUNET_OK; } addr = papi->address_to_string (papi->cls, address->address, address->address_length); if ((NULL == addr) || (0 == strlen (addr))) return GNUNET_OK; addr_dup = GNUNET_strdup (addr); if (NULL != (pos = strstr (addr_dup, "_server"))) GNUNET_memcpy (pos, client_str, strlen (client_str)); /* Replace all server addresses with client addresses */ seconds = expiration.abs_value_us / 1000LL / 1000LL; t = gmtime (&seconds); GNUNET_asprintf (&ret, "%s%c%s%c%s%c%s", ctx->uri, GNUNET_HELLO_URI_SEP, strftime (tbuf, sizeof(tbuf), "%Y%m%d%H%M%S", t) ? tbuf : "0", GNUNET_HELLO_URI_SEP, address->transport_name, GNUNET_HELLO_URI_SEP, addr_dup); GNUNET_free (addr_dup); GNUNET_free (ctx->uri); ctx->uri = ret; return GNUNET_OK; } /** * Compose a hello URI string from a hello message. * * @param hello Hello message * @param plugins_find Function to find transport plugins by name * @return Hello URI string */ char * GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello, GNUNET_HELLO_TransportPluginsFind plugins_find) { struct GNUNET_HELLO_ComposeUriContext ctx; char *pkey; ctx.plugins_find = plugins_find; pkey = GNUNET_CRYPTO_eddsa_public_key_to_string (&hello->publicKey); GNUNET_asprintf (&ctx.uri, "%s%s", (GNUNET_YES == GNUNET_HELLO_is_friend_only (hello)) ? GNUNET_FRIEND_HELLO_URI_PREFIX : GNUNET_HELLO_URI_PREFIX, pkey); GNUNET_free (pkey); GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &add_address_to_uri, &ctx); return ctx.uri; } /* ************************* Parse HELLO URI ********************* */ /** * We're building a HELLO. Parse the next address from the * parsing context and append it. * * @param cls the `struct GNUNET_HELLO_ParseUriContext` * @param max number of bytes available for HELLO construction * @param buffer where to copy the next address (in binary format) * @return number of bytes added to buffer, #GNUNET_SYSERR on error */ static ssize_t add_address_to_hello (void *cls, size_t max, void *buffer) { struct GNUNET_HELLO_ParseUriContext *ctx = cls; const char *tname; const char *address; char *uri_address; const char *end; char *plugin_name; struct tm expiration_time; time_t expiration_seconds; struct GNUNET_TIME_Absolute expire; struct GNUNET_TRANSPORT_PluginFunctions *papi; void *addr; size_t addr_len; struct GNUNET_HELLO_Address haddr; ssize_t ret; if (NULL == ctx->pos) return GNUNET_SYSERR; if (GNUNET_HELLO_URI_SEP != ctx->pos[0]) { ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return GNUNET_SYSERR; } ctx->pos++; if (('0' == ctx->pos[0]) && (GNUNET_HELLO_URI_SEP == ctx->pos[1])) { expire = GNUNET_TIME_UNIT_FOREVER_ABS; tname = ctx->pos + 1; } else { memset (&expiration_time, 0, sizeof(expiration_time)); tname = strptime (ctx->pos, "%Y%m%d%H%M%S", &expiration_time); if (NULL == tname) { ctx->ret = GNUNET_SYSERR; GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ( "Failed to parse HELLO message: missing expiration time\n")); GNUNET_break (0); return GNUNET_SYSERR; } expiration_seconds = mktime (&expiration_time); if (expiration_seconds == (time_t) -1) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ( "Failed to parse HELLO message: invalid expiration time\n")); ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return GNUNET_SYSERR; } expire.abs_value_us = expiration_seconds * 1000LL * 1000LL; } if (GNUNET_HELLO_URI_SEP != tname[0]) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Failed to parse HELLO message: malformed\n")); ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return GNUNET_SYSERR; } tname++; address = strchr (tname, (int) GNUNET_HELLO_URI_SEP); if (NULL == address) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ( "Failed to parse HELLO message: missing transport plugin\n")); ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return GNUNET_SYSERR; } address++; end = strchr (address, (int) GNUNET_HELLO_URI_SEP); ctx->pos = end; ctx->counter_total++; plugin_name = GNUNET_strndup (tname, address - (tname + 1)); papi = ctx->plugins_find (plugin_name); if (NULL == papi) { /* Not an error - we might just not have the right plugin. * Skip this part, advance to the next one and recurse. * But only if this is not the end of string. */ GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Plugin `%s' not found, skipping address\n"), plugin_name); GNUNET_free (plugin_name); return 0; } if (NULL == papi->string_to_address) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Plugin `%s' does not support URIs yet\n"), plugin_name); GNUNET_free (plugin_name); GNUNET_break (0); return 0; } uri_address = GNUNET_strndup (address, end - address); if (GNUNET_OK != papi->string_to_address (papi->cls, uri_address, strlen (uri_address) + 1, &addr, &addr_len)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Failed to parse `%s' as an address for plugin `%s'\n"), uri_address, plugin_name); GNUNET_free (plugin_name); GNUNET_free (uri_address); return 0; } GNUNET_free (uri_address); /* address.peer is unset - not used by add_address() */ haddr.address_length = addr_len; haddr.address = addr; haddr.transport_name = plugin_name; ret = GNUNET_HELLO_add_address (&haddr, expire, buffer, max); ctx->counter_added++; GNUNET_free (addr); GNUNET_free (plugin_name); return ret; } /** * Parse a hello URI string to a hello message. * * @param uri URI string to parse * @param pubkey Pointer to struct where public key is parsed * @param hello Pointer to struct where hello message is parsed * @param plugins_find Function to find transport plugins by name * @return #GNUNET_OK on success, #GNUNET_SYSERR if the URI was invalid, #GNUNET_NO on other errors */ int GNUNET_HELLO_parse_uri (const char *uri, struct GNUNET_CRYPTO_EddsaPublicKey *pubkey, struct GNUNET_HELLO_Message **hello, GNUNET_HELLO_TransportPluginsFind plugins_find) { const char *pks; const char *exc; int friend_only; struct GNUNET_HELLO_ParseUriContext ctx; if (0 == strncmp (uri, GNUNET_HELLO_URI_PREFIX, strlen (GNUNET_HELLO_URI_PREFIX))) { pks = &uri[strlen (GNUNET_HELLO_URI_PREFIX)]; friend_only = GNUNET_NO; } else if (0 == strncmp (uri, GNUNET_FRIEND_HELLO_URI_PREFIX, strlen (GNUNET_FRIEND_HELLO_URI_PREFIX))) { pks = &uri[strlen (GNUNET_FRIEND_HELLO_URI_PREFIX)]; friend_only = GNUNET_YES; } else return GNUNET_SYSERR; exc = strchr (pks, GNUNET_HELLO_URI_SEP); if (GNUNET_OK != GNUNET_STRINGS_string_to_data (pks, (NULL == exc) ? strlen (pks) : (exc - pks), (unsigned char *) pubkey, sizeof(*pubkey))) return GNUNET_SYSERR; ctx.pos = exc; ctx.ret = GNUNET_OK; ctx.counter_total = 0; ctx.counter_added = 0; ctx.plugins_find = plugins_find; *hello = GNUNET_HELLO_create (pubkey, &add_address_to_hello, &ctx, friend_only); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "HELLO URI contained %u addresses, added %u addresses\n", ctx.counter_total, ctx.counter_added); return ctx.ret; } /* end of hello.c */