X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fhello%2Fhello.c;h=690a0961a34ffaa344277748415c8fe9a2c3db80;hb=7c1f035ed971e12882cd7a65c7d36883842945b1;hp=79d0edf8dac6049265d8fab6d9c7315fbd97a39f;hpb=120afa6058ba579887a9b417ec86cf06926d765e;p=oweals%2Fgnunet.git diff --git a/src/hello/hello.c b/src/hello/hello.c index 79d0edf8d..690a0961a 100644 --- a/src/hello/hello.c +++ b/src/hello/hello.c @@ -1,10 +1,10 @@ /* This file is part of GNUnet. - (C) 2009 Christian Grothoff (and other contributing authors) + 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 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 @@ -14,89 +14,120 @@ You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the - Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. + Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301, USA. */ /** * @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_server_lib.h" +#include "gnunet_util_lib.h" +#include "gnunet_transport_plugin.h" /** - * A HELLO message is used to exchange information about - * transports with other peers. This struct is always - * followed by the actual network addresses which have - * the format: - * - * 1) transport-name (0-terminated) - * 2) address-length (uint32_t, network byte order; possibly - * unaligned!) - * 3) address expiration (GNUNET_TIME_AbsoluteNBO); possibly - * unaligned!) - * 4) address (address-length bytes; possibly unaligned!) + * Context used for building our own URI. */ -struct GNUNET_HELLO_Message +struct GNUNET_HELLO_ComposeUriContext { /** - * Type will be GNUNET_MESSAGE_TYPE_HELLO. + * Final URI. */ - struct GNUNET_MessageHeader header; + char *uri; /** - * Always zero (for alignment). + * Function for finding transport plugins by name. */ - uint32_t reserved GNUNET_PACKED; + GNUNET_HELLO_TransportPluginsFind plugins_find; +}; + +/** + * Context for #add_address_to_hello(). + */ +struct GNUNET_HELLO_ParseUriContext +{ /** - * The public key of the peer. + * Position in the URI with the next address to parse. */ - struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded publicKey; + 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 tname name of the transport plugin - * @param expiration expiration for the address - * @param addr the address - * @param addr_len length of the address in bytes - * @param target where to copy the address + * @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 char *tname, +GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration, - const void *addr, - size_t addr_len, char *target, size_t max) + char *target, + size_t max) { - uint32_t alen; + uint16_t alen; size_t slen; struct GNUNET_TIME_AbsoluteNBO exp; - slen = strlen (tname) + 1; - if (slen + sizeof (uint32_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO) + - addr_len > max) + 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 = htonl ((uint32_t) addr_len); - memcpy (target, tname, slen); - memcpy (&target[slen], &alen, sizeof (uint32_t)); - slen += sizeof (uint32_t); - memcpy (&target[slen], &exp, sizeof (struct GNUNET_TIME_AbsoluteNBO)); + 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); - memcpy (&target[slen], addr, addr_len); - slen += addr_len; + GNUNET_memcpy (&target[slen], address->address, address->address_length); + slen += address->address_length; return slen; } @@ -105,15 +136,17 @@ GNUNET_HELLO_add_address (const char *tname, * 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 buf) + * @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 max is not large enough + * @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, uint32_t * ralen) +get_hello_address_size (const char *buf, + size_t max, + uint16_t *ralen) { const char *pos; - uint32_t alen; + uint16_t alen; size_t left; size_t slen; @@ -121,35 +154,34 @@ get_hello_address_size (const char *buf, size_t max, uint32_t * ralen) pos = buf; slen = 1; while ((left > 0) && ('\0' != *pos)) - { - left--; - pos++; - slen++; - } - if ('\0' != *pos) - { - /* 0-termination not found */ - GNUNET_break_op (0); - abort (); - return 0; - } + { + left--; + pos++; + slen++; + } + if (0 == left) + { + /* 0-termination not found */ + GNUNET_break_op (0); + return 0; + } pos++; - if (left < sizeof (uint32_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO)) - { - /* not enough space for addrlen */ - GNUNET_break_op (0); - return 0; - } - memcpy (&alen, pos, sizeof (uint32_t)); - alen = ntohl (alen); + 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 (uint32_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO); + slen += alen + sizeof (uint16_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO); if (max < slen) - { - /* not enough space for addr */ - GNUNET_break_op (0); - return 0; - } + { + /* not enough space for addr */ + GNUNET_break_op (0); + return 0; + } return slen; } @@ -159,34 +191,51 @@ get_hello_address_size (const char *buf, size_t max, uint32_t * ralen) * 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_RsaPublicKeyBinaryEncoded - *publicKey, +GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *public_key, GNUNET_HELLO_GenerateAddressListCallback addrgen, - void *addrgen_cls) + void *addrgen_cls, + int friend_only) { - char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 256 - + 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; - while (0 != (ret = addrgen (addrgen_cls, max, &buffer[used]))) + 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); - memcpy (&hello->publicKey, publicKey, - sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded)); - memcpy (&hello[1], buffer, used); + hello->friend_only = htonl (friend_only); + hello->publicKey = *public_key; + GNUNET_memcpy (&hello[1], + buffer, + used); return hello; } @@ -198,13 +247,16 @@ GNUNET_HELLO_create (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded * @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 it + * @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) + GNUNET_HELLO_AddressIterator it, + void *it_cls) { + struct GNUNET_HELLO_Address address; uint16_t msize; struct GNUNET_HELLO_Message *ret; const char *inptr; @@ -212,145 +264,248 @@ GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg, size_t esize; size_t wpos; char *woff; - uint32_t alen; + 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); - memcpy (ret, msg, msize); - } + { + ret = GNUNET_malloc (msize); + GNUNET_memcpy (ret, + msg, + msize); + } inptr = (const char *) &msg[1]; insize = msize - sizeof (struct GNUNET_HELLO_Message); wpos = 0; - woff = (ret != NULL) ? (char *) &ret[1] : NULL; + 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) ) { - esize = get_hello_address_size (inptr, insize, &alen); - if (esize == 0) - { - GNUNET_break (0); - GNUNET_free_non_null (ret); - return NULL; - } - memcpy (&expire, - &inptr[esize - alen - sizeof (struct GNUNET_TIME_AbsoluteNBO)], - sizeof (struct GNUNET_TIME_AbsoluteNBO)); - iret = it (it_cls, - inptr, - GNUNET_TIME_absolute_ntoh (expire), - &inptr[esize - alen], alen); - if (iret == GNUNET_SYSERR) - { - if (ret != NULL) - ret->header.size = - ntohs (sizeof (struct GNUNET_HELLO_Message) + wpos); - return ret; - } - if ((iret == GNUNET_OK) && (ret != NULL)) - { - memcpy (woff, inptr, esize); - woff += esize; - wpos += esize; - } - insize -= esize; - inptr += esize; + /* copy address over */ + GNUNET_memcpy (woff, + inptr, + esize); + woff += esize; + wpos += esize; } - if (ret != NULL) + 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 { - const void *addr; - size_t addrlen; + /** + * 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 char *tname, - struct GNUNET_TIME_Absolute expiration, - const void *addr, size_t addrlen) + const struct GNUNET_HELLO_Address *address, + struct GNUNET_TIME_Absolute expiration) { struct ExpireContext *ec = cls; - if ((addrlen == ec->addrlen) && (0 == memcmp (addr, ec->addr, addrlen))) - { - ec->found = GNUNET_YES; - ec->expiration = expiration; - return GNUNET_SYSERR; /* done here */ - } - return GNUNET_OK; + 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 char *tname, - struct GNUNET_TIME_Absolute expiration, - const void *addr, size_t addrlen) + const struct GNUNET_HELLO_Address *address, + struct GNUNET_TIME_Absolute expiration) { struct MergeContext *mc = cls; struct ExpireContext ec; - ec.addr = addr; - ec.addrlen = addrlen; + ec.address = address; ec.found = GNUNET_NO; - GNUNET_HELLO_iterate_addresses (mc->other, GNUNET_NO, &get_match_exp, &ec); - if ((ec.found == GNUNET_NO) || - ((ec.expiration.value < expiration.value) || - ((ec.expiration.value == expiration.value) && - (mc->take_equal == GNUNET_YES)))) - mc->ret += GNUNET_HELLO_add_address (tname, - expiration, - addr, - addrlen, - &mc->buf[mc->ret], - mc->max - mc->ret); + /* 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; } -static size_t -merge_addr (void *cls, size_t max, void *buf) +/** + * 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 (mc->h1 == NULL) - return 0; + 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; - GNUNET_HELLO_iterate_addresses (mc->h1, GNUNET_NO, ©_latest, mc); + /* 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; - GNUNET_HELLO_iterate_addresses (mc->h2, GNUNET_NO, ©_latest, mc); + /* 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; } @@ -363,72 +518,111 @@ merge_addr (void *cls, size_t max, void *buf) * * @param h1 first HELLO message * @param h2 the second HELLO message - * @return the combined 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; - return GNUNET_HELLO_create (&h1->publicKey, &merge_addr, &mc); + 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 char *tname, - struct GNUNET_TIME_Absolute expiration, - const void *addr, size_t addrlen) + const struct GNUNET_HELLO_Address *address, + struct GNUNET_TIME_Absolute expiration) { struct DeltaContext *dc = cls; int ret; struct ExpireContext ec; - ec.addr = addr; - ec.addrlen = addrlen; + ec.address = address; ec.found = GNUNET_NO; GNUNET_HELLO_iterate_addresses (dc->old_hello, - GNUNET_NO, &get_match_exp, &ec); - if ((ec.found == GNUNET_YES) && - ((ec.expiration.value > expiration.value) || - (ec.expiration.value >= dc->expiration_limit.value))) - return GNUNET_YES; /* skip */ - ret = dc->it (dc->it_cls, tname, expiration, addr, addrlen); + 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 "new_hello" that - * are NOT already present in "old_hello". + * 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 old_hello + * @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 it + * @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_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) { @@ -438,7 +632,11 @@ GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message dc.it = it; dc.it_cls = it_cls; dc.old_hello = old_hello; - GNUNET_HELLO_iterate_addresses (new_hello, GNUNET_NO, &delta_match, &dc); + GNUNET_assert (NULL == + GNUNET_HELLO_iterate_addresses (new_hello, + GNUNET_NO, + &delta_match, + &dc)); } @@ -451,6 +649,7 @@ 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; @@ -459,25 +658,611 @@ GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello) /** - * Get the public key from a HELLO message. + * Get the peer identity from a HELLO message. * * @param hello the hello message - * @param publicKey where to copy the public key information, can be NULL - * @return GNUNET_SYSERR if the HELLO was malformed + * @param peer where to store the peer's identity + * @return #GNUNET_SYSERR if the HELLO was malformed */ int -GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello, - struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded - *publicKey) +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; - *publicKey = hello->publicKey; + 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 != + memcmp (&h1->publicKey, + &h2->publicKey, + sizeof (struct GNUNET_CRYPTO_EddsaPublicKey))) + 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 */