/* This file is part of GNUnet. (C) 2009 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file hello/hello.c * @brief helper library for handling HELLOs * @author Christian Grothoff */ #include "platform.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_util_lib.h" #include "gnunet_transport_plugin.h" GNUNET_NETWORK_STRUCT_BEGIN /** * 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 (uint16_t, network byte order; possibly * unaligned!) * 3) address expiration (GNUNET_TIME_AbsoluteNBO); possibly * unaligned!) * 4) address (address-length bytes; possibly unaligned!) */ struct GNUNET_HELLO_Message { /** * Type will be GNUNET_MESSAGE_TYPE_HELLO. */ struct GNUNET_MessageHeader header; /** * Always zero (for alignment). */ uint32_t reserved GNUNET_PACKED; /** * The public key of the peer. */ struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded publicKey; }; GNUNET_NETWORK_STRUCT_END /** * 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; /** * Function for finding transport plugins by name. */ GNUNET_HELLO_TransportPluginsFind plugins_find; }; /** * Copy the given address information into * the given buffer using the format of HELLOs. * * @param address the address * @param expiration expiration for the address * @param target where to copy the 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); memcpy (target, address->transport_name, slen); memcpy (&target[slen], &alen, sizeof (uint16_t)); slen += sizeof (uint16_t); memcpy (&target[slen], &exp, sizeof (struct GNUNET_TIME_AbsoluteNBO)); slen += sizeof (struct GNUNET_TIME_AbsoluteNBO); 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 buf) * @param ralen set to the address length * @return size of the entry, or 0 if 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 (left == 0) { /* 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; } 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. * * @return the hello message */ struct GNUNET_HELLO_Message * GNUNET_HELLO_create (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey, GNUNET_HELLO_GenerateAddressListCallback addrgen, void *addrgen_cls) { char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - 256 - sizeof (struct GNUNET_HELLO_Message)]; size_t max; size_t used; size_t ret; struct GNUNET_HELLO_Message *hello; max = sizeof (buffer); used = 0; if (addrgen != NULL) { while (0 != (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); 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 it */ 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)) return NULL; ret = NULL; if (return_modified) { ret = GNUNET_malloc (msize); 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; GNUNET_CRYPTO_hash (&msg->publicKey, sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &address.peer.hashPubKey); while (insize > 0) { 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)); address.address = &inptr[esize - alen]; address.address_length = alen; address.transport_name = inptr; iret = it (it_cls, &address, GNUNET_TIME_absolute_ntoh (expire)); 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; } if (ret != NULL) ret->header.size = ntohs (sizeof (struct GNUNET_HELLO_Message) + wpos); return ret; } struct ExpireContext { const struct GNUNET_HELLO_Address *address; int found; struct GNUNET_TIME_Absolute expiration; }; 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)) { ec->found = GNUNET_YES; ec->expiration = expiration; return GNUNET_SYSERR; /* done here */ } return GNUNET_OK; } struct MergeContext { const struct GNUNET_HELLO_Message *h1; const struct GNUNET_HELLO_Message *h2; const struct GNUNET_HELLO_Message *other; char *buf; size_t max; size_t ret; int take_equal; }; 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; GNUNET_HELLO_iterate_addresses (mc->other, GNUNET_NO, &get_match_exp, &ec); if ((ec.found == GNUNET_NO) || (ec.expiration.abs_value < expiration.abs_value) || ((ec.expiration.abs_value == expiration.abs_value) && (mc->take_equal == GNUNET_YES))) { 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) { struct MergeContext *mc = cls; if (mc->h1 == NULL) return 0; 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); mc->take_equal = GNUNET_YES; mc->other = mc->h1; GNUNET_HELLO_iterate_addresses (mc->h2, GNUNET_NO, ©_latest, mc); 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 }; return GNUNET_HELLO_create (&h1->publicKey, &merge_addr, &mc); } struct DeltaContext { struct GNUNET_TIME_Absolute expiration_limit; GNUNET_HELLO_AddressIterator it; void *it_cls; const struct GNUNET_HELLO_Message *old_hello; }; 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 ((ec.found == GNUNET_YES) && ((ec.expiration.abs_value > expiration.abs_value) || (ec.expiration.abs_value >= dc->expiration_limit.abs_value))) return GNUNET_YES; /* skip */ ret = dc->it (dc->it_cls, address, expiration); return ret; } /** * Iterate over addresses in "new_hello" that * are NOT already present in "old_hello". * * @param new_hello a HELLO message * @param old_hello a HELLO message * @param expiration_limit ignore addresses in old_hello * that expired before the given time stamp * @param it iterator to call on each address * @param it_cls closure for 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_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 public key 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 */ int GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello, struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey) { 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; return GNUNET_OK; } /** * 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; GNUNET_CRYPTO_hash (&hello->publicKey, sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &peer->hashPubKey); 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; } struct EqualsContext { struct GNUNET_TIME_Absolute expiration_limit; struct GNUNET_TIME_Absolute result; const struct GNUNET_HELLO_Message *h2; const struct GNUNET_HELLO_Address *address; struct GNUNET_TIME_Absolute expiration; int found; }; 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 < ec->expiration_limit.abs_value) return GNUNET_YES; if (0 == GNUNET_HELLO_address_cmp (address, ec->address)) { ec->found = GNUNET_YES; if (expiration.abs_value < ec->expiration.abs_value) ec->result = GNUNET_TIME_absolute_min (expiration, ec->result); return GNUNET_SYSERR; } return GNUNET_YES; } 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 < ec->expiration_limit.abs_value) return GNUNET_YES; ec->address = address; ec->expiration = expiration; ec->found = GNUNET_NO; GNUNET_HELLO_iterate_addresses (ec->h2, GNUNET_NO, &find_other_matching, ec); if (ec->found == GNUNET_NO) { 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 '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 >= now if * they only differ in timestamps; * zero if the some addresses with expirations >= 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 (0 != memcmp (&h1->publicKey, &h2->publicKey, sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded))) return GNUNET_TIME_UNIT_ZERO_ABS; ec.expiration_limit = now; ec.result = GNUNET_TIME_UNIT_FOREVER_ABS; ec.h2 = h2; GNUNET_HELLO_iterate_addresses (h1, GNUNET_NO, &find_matching, &ec); if (ec.result.abs_value == GNUNET_TIME_UNIT_ZERO.rel_value) return ec.result; ec.h2 = h1; GNUNET_HELLO_iterate_addresses (h2, GNUNET_NO, &find_matching, &ec); return ec.result; } static int find_min_expire (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { struct GNUNET_TIME_Absolute *min = cls; *min = GNUNET_TIME_absolute_min (*min, 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.abs_value = 0; GNUNET_HELLO_iterate_addresses (msg, GNUNET_NO, &find_min_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/0430205UC7D56PTQK8NV05776671CNN44FK4TL6D0GQ35OMF8MEN4RNMKA5UF6AL3DQO8B1SC5AQF50SQ2MABIRU4HC8H2HAJKJ59JL1JVRJAK308F9GASRFLMGUBB5TQ5AKR94AS5T3MDG8B9O1EMPRKB0HVCG7T6QPP4CDJ913LAEHVJ2DI1TOBB15Q1JIT5ARBOD12U4SIGRFDV3Q7T66G4TBVSJJ90UQF1BG29TGJJKLGEIMSPHHKO544D6EALQ4F2K0416311JC22GVAD48R616I7VK03K7MP7N0RS2MBV1TE9JV8CK1LSQMR7KCDRTLDA6917UGA67DHTGHERIACCGQ54TGSR48RMSGS9BA5HLMOKASFC1I6V4TT09TUGCU8GNDHQF0JF3H7LPV59UL5I38QID040G000!20120302010059!TCP!192.168.0.1:2086!TCP!64.23.8.174:0 * gnunet://hello/0430205UC7D56PTQK8NV05776671CNN44FK4TL6D0GQ35OMF8MEN4RNMKA5UF6AL3DQO8B1SC5AQF50SQ2MABIRU4HC8H2HAJKJ59JL1JVRJAK308F9GASRFLMGUBB5TQ5AKR94AS5T3MDG8B9O1EMPRKB0HVCG7T6QPP4CDJ913LAEHVJ2DI1TOBB15Q1JIT5ARBOD12U4SIGRFDV3Q7T66G4TBVSJJ90UQF1BG29TGJJKLGEIMSPHHKO544D6EALQ4F2K0416311JC22GVAD48R616I7VK03K7MP7N0RS2MBV1TE9JV8CK1LSQMR7KCDRTLDA6917UGA67DHTGHERIACCGQ54TGSR48RMSGS9BA5HLMOKASFC1I6V4TT09TUGCU8GNDHQF0JF3H7LPV59UL5I38QID040G000!20120302010059!TCP!(2001:db8:85a3:8d3:1319:8a2e:370:7348):2086 * *

*/ /* ************************* Compose HELLO URI ************************** */ /** * Replace all characters in the input 'in' according * to the mapping. The mapping says to map each character * in 'oldchars' to the corresponding character (by offset) * in 'newchars'. * * @param in input string to remap * @param oldchars characters to replace * @param newchars replacement characters, must have same length as 'oldchars' * @return copy of string with replacement applied. */ static char * map_characters (const char *in, const char *oldchars, const char *newchars) { char *ret; const char *off; size_t i; GNUNET_assert (strlen (oldchars) == strlen (newchars)); ret = GNUNET_strdup (in); i = 0; while (ret[i] != '\0') { off = strchr (oldchars, ret[i]); if (NULL != off) ret[i] = newchars[off - oldchars]; i++; } return ret; } /** * Function that is called on each address of this peer. * Expands the corresponding URI string. * * @param cls the 'GNUNET_HELLO_GetUriContext' * @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 *uri_addr; char *ret; char tbuf[16] = ""; struct tm *t; time_t seconds; papi = ctx->plugins_find (address->transport_name); if (papi == NULL) { /* 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 ( (addr == NULL) || (strlen(addr) == 0) ) return GNUNET_OK; /* For URIs we use '(' and ')' instead of '[' and ']' as brackets are reserved characters in URIs */ uri_addr = map_characters (addr, "[]", "()"); seconds = expiration.abs_value / 1000; t = gmtime (&seconds); GNUNET_asprintf (&ret, "%s!%s!%s!%s", ctx->uri, strftime (tbuf, sizeof (tbuf), "%Y%m%d%H%M%S", t) ? tbuf : "0", address->transport_name, uri_addr); GNUNET_free (uri_addr); 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; ctx.plugins_find = plugins_find; char *pkey = GNUNET_CRYPTO_rsa_public_key_to_string (&(hello->publicKey)); GNUNET_asprintf (&(ctx.uri), "%s%s", 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_AddressParsingContext' * @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 */ static size_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; char *plugin_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; size_t ret; if (NULL == ctx->pos) return 0; if ('!' != ctx->pos[0]) { ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return 0; } ctx->pos++; if ('0' == ctx->pos[0] && '!' == 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 0; } 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 0; } expire.abs_value = expiration_seconds * 1000; } if ('!' != tname[0]) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Failed to parse HELLO message: malformed\n")); ctx->ret = GNUNET_SYSERR; GNUNET_break (0); return 0; } tname++; address = strchr (tname, (int) '!'); 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 0; } address++; end = strchr (address, (int) '!'); ctx->pos = end; 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_ERROR, _("Plugin `%s' not found\n"), plugin_name); GNUNET_free (plugin_name); GNUNET_break (0); return 0; } if (NULL == papi->string_to_address) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("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); /* For URIs we use '(' and ')' instead of '[' and ']' as brackets are reserved characters in URIs; need to convert back to '[]' for the plugin */ plugin_address = map_characters (uri_address, "()", "[]"); GNUNET_free (uri_address); if (GNUNET_OK != papi->string_to_address (papi->cls, plugin_address, strlen (plugin_address) + 1, &addr, &addr_len)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Failed to parse `%s' as an address for plugin `%s'\n"), plugin_address, plugin_name); GNUNET_free (plugin_name); GNUNET_free (plugin_address); return 0; } GNUNET_free (plugin_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); 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_RsaPublicKeyBinaryEncoded *pubkey, struct GNUNET_HELLO_Message **hello, GNUNET_HELLO_TransportPluginsFind plugins_find) { const char *pks; const char *exc; struct GNUNET_HELLO_ParseUriContext ctx; if (0 != strncmp (uri, GNUNET_HELLO_URI_PREFIX, strlen (GNUNET_HELLO_URI_PREFIX))) return GNUNET_SYSERR; pks = &uri[strlen (GNUNET_HELLO_URI_PREFIX)]; exc = strstr (pks, "!"); 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.plugins_find = plugins_find; *hello = GNUNET_HELLO_create (pubkey, &add_address_to_hello, &ctx); return ctx.ret; } /* end of hello.c */