commit fd93622cc897ede9c52205390bfb71e2e8588259 Author: Nick Mathewson <nickm@torproject.org> Date: Fri Feb 22 12:17:23 2013 -0500 Use chunks, not buffers, for router descriptors --- src/or/router.c | 143 ++++++++++++++++++++------------------------------ src/or/router.h | 4 +- src/test/test_dir.c | 12 +++-- 3 files changed, 67 insertions(+), 92 deletions(-) diff --git a/src/or/router.c b/src/or/router.c index 95aa70a..1b5909e 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -1927,9 +1927,8 @@ router_rebuild_descriptor(int force) /* ri was allocated with tor_malloc_zero, so there is no need to * zero ri->cache_info.extra_info_digest here. */ } - ri->cache_info.signed_descriptor_body = tor_malloc(8192); - if (router_dump_router_to_string(ri->cache_info.signed_descriptor_body, 8192, - ri, get_server_identity_key()) < 0) { + if (! (ri->cache_info.signed_descriptor_body = router_dump_router_to_string( + ri, get_server_identity_key()))) { log_warn(LD_BUG, "Couldn't generate router descriptor."); routerinfo_free(ri); extrainfo_free(ei); @@ -2229,54 +2228,53 @@ get_platform_str(char *platform, size_t len) #define DEBUG_ROUTER_DUMP_ROUTER_TO_STRING /** OR only: Given a routerinfo for this router, and an identity key to sign - * with, encode the routerinfo as a signed server descriptor and write the - * result into <b>s</b>, using at most <b>maxlen</b> bytes. Return -1 on - * failure, and the number of bytes used on success. + * with, encode the routerinfo as a signed server descriptor and return a new + * string encoding the result, or NULL on failure. */ -int -router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, +char * +router_dump_router_to_string(routerinfo_t *router, crypto_pk_t *ident_key) { - char *onion_pkey; /* Onion key, PEM-encoded. */ - char *identity_pkey; /* Identity key, PEM-encoded. */ + char *onion_pkey = NULL; /* Onion key, PEM-encoded. */ + char *identity_pkey = NULL; /* Identity key, PEM-encoded. */ char digest[DIGEST_LEN]; char published[ISO_TIME_LEN+1]; char fingerprint[FINGERPRINT_LEN+1]; int has_extra_info_digest; char extra_info_digest[HEX_DIGEST_LEN+1]; size_t onion_pkeylen, identity_pkeylen; - size_t written; - int result=0; - char *family_line; + char *family_line = NULL; char *extra_or_address = NULL; const or_options_t *options = get_options(); + smartlist_t *chunks = NULL; + char *output = NULL; + size_t output_len; /* Make sure the identity key matches the one in the routerinfo. */ if (!crypto_pk_eq_keys(ident_key, router->identity_pkey)) { log_warn(LD_BUG,"Tried to sign a router with a private key that didn't " "match router's public key!"); - return -1; + goto err; } /* record our fingerprint, so we can include it in the descriptor */ if (crypto_pk_get_fingerprint(router->identity_pkey, fingerprint, 1)<0) { log_err(LD_BUG,"Error computing fingerprint"); - return -1; + goto err; } /* PEM-encode the onion key */ if (crypto_pk_write_public_key_to_string(router->onion_pkey, &onion_pkey,&onion_pkeylen)<0) { log_warn(LD_BUG,"write onion_pkey to string failed!"); - return -1; + goto err; } /* PEM-encode the identity key */ if (crypto_pk_write_public_key_to_string(router->identity_pkey, &identity_pkey,&identity_pkeylen)<0) { log_warn(LD_BUG,"write identity_pkey to string failed!"); - tor_free(onion_pkey); - return -1; + goto err; } /* Encode the publication time. */ @@ -2311,8 +2309,9 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, } } + chunks = smartlist_new(); /* Generate the easy portion of the router descriptor. */ - result = tor_snprintf(s, maxlen, + smartlist_add_asprintf(chunks, "router %s %s %d 0 %d\n" "%s" "platform %s\n" @@ -2347,28 +2346,11 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, options->HidServDirectoryV2 ? "hidden-service-dir\n" : "", options->AllowSingleHopExits ? "allow-single-hop-exits\n" : ""); - tor_free(family_line); - tor_free(onion_pkey); - tor_free(identity_pkey); - tor_free(extra_or_address); - - if (result < 0) { - log_warn(LD_BUG,"descriptor snprintf #1 ran out of room!"); - return -1; - } - /* From now on, we use 'written' to remember the current length of 's'. */ - written = result; - if (options->ContactInfo && strlen(options->ContactInfo)) { const char *ci = options->ContactInfo; if (strchr(ci, '\n') || strchr(ci, '\r')) ci = escaped(ci); - result = tor_snprintf(s+written,maxlen-written, "contact %s\n", ci); - if (result<0) { - log_warn(LD_BUG,"descriptor snprintf #2 ran out of room!"); - return -1; - } - written += result; + smartlist_add_asprintf(chunks, "contact %s\n", ci); } #ifdef CURVE25519_ENABLED @@ -2377,105 +2359,94 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, base64_encode(kbuf, sizeof(kbuf), (const char *)router->onion_curve25519_pkey->public_key, CURVE25519_PUBKEY_LEN); - result = tor_snprintf(s+written,maxlen-written, "ntor-onion-key %s", - kbuf); - if (result<0) { - log_warn(LD_BUG,"descriptor snprintf ran out of room!"); - return -1; - } - written += result; + smartlist_add_asprintf(chunks, "ntor-onion-key %s", kbuf); } #endif /* Write the exit policy to the end of 's'. */ if (!router->exit_policy || !smartlist_len(router->exit_policy)) { - strlcat(s+written, "reject *:*\n", maxlen-written); - written += strlen("reject *:*\n"); + smartlist_add(chunks, tor_strdup("reject *:*\n")); } else if (router->exit_policy) { int i; for (i = 0; i < smartlist_len(router->exit_policy); ++i) { + char pbuf[POLICY_BUF_LEN]; addr_policy_t *tmpe = smartlist_get(router->exit_policy, i); + int result; if (tor_addr_family(&tmpe->addr) == AF_INET6) continue; /* Don't include IPv6 parts of address policy */ - result = policy_write_item(s+written, maxlen-written, tmpe, 1); + result = policy_write_item(pbuf, POLICY_BUF_LEN, tmpe, 1); if (result < 0) { log_warn(LD_BUG,"descriptor policy_write_item ran out of room!"); - return -1; + goto err; } - tor_assert(result == (int)strlen(s+written)); - written += result; - if (written+2 > maxlen) { - log_warn(LD_BUG,"descriptor policy_write_item ran out of room (2)!"); - return -1; - } - s[written++] = '\n'; + smartlist_add_asprintf(chunks, "%s\n", pbuf); } } if (router->ipv6_exit_policy) { char *p6 = write_short_policy(router->ipv6_exit_policy); if (p6 && strcmp(p6, "reject 1-65535")) { - result = tor_snprintf(s+written, maxlen-written, + smartlist_add_asprintf(chunks, "ipv6-policy %s\n", p6); - if (result<0) { - log_warn(LD_BUG,"Descriptor printf of policy ran out of room"); - tor_free(p6); - return -1; - } - written += result; } tor_free(p6); } - if (written + DIROBJ_MAX_SIG_LEN > maxlen) { - /* Not enough room for signature. */ - log_warn(LD_BUG,"not enough room left in descriptor for signature!"); - return -1; - } - /* Sign the descriptor */ - strlcpy(s+written, "router-signature\n", maxlen-written); - written += strlen(s+written); - s[written] = '\0'; - if (router_get_router_hash(s, strlen(s), digest) < 0) { - return -1; + smartlist_add(chunks, tor_strdup("router-signature\n")); + + output = smartlist_join_strings(chunks, "", 0, NULL); +#define MAX_DESC_SIGNATURE_LEN 4096 + output_len = strlen(output) + MAX_DESC_SIGNATURE_LEN + 1; + output = tor_realloc(output, output_len); + + if (router_get_router_hash(output, strlen(output), digest) < 0) { + goto err; } note_crypto_pk_op(SIGN_RTR); - if (router_append_dirobj_signature(s+written,maxlen-written, + if (router_append_dirobj_signature(output, output_len, digest,DIGEST_LEN,ident_key)<0) { log_warn(LD_BUG, "Couldn't sign router descriptor"); - return -1; + goto err; } - written += strlen(s+written); - if (written+2 > maxlen) { - log_warn(LD_BUG,"Not enough room to finish descriptor."); - return -1; - } /* include a last '\n' */ - s[written] = '\n'; - s[written+1] = 0; + strlcat(output, "\n", output_len); #ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING { char *s_dup; const char *cp; routerinfo_t *ri_tmp; - cp = s_dup = tor_strdup(s); + cp = s_dup = tor_strdup(output); ri_tmp = router_parse_entry_from_string(cp, NULL, 1, 0, NULL); if (!ri_tmp) { log_err(LD_BUG, "We just generated a router descriptor we can't parse."); - log_err(LD_BUG, "Descriptor was: <<%s>>", s); - return -1; + log_err(LD_BUG, "Descriptor was: <<%s>>", output); + goto err; } tor_free(s_dup); routerinfo_free(ri_tmp); } #endif - return (int)written+1; + goto done; + + err: + tor_free(output); /* sets output to NULL */ + done: + if (chunks) { + SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp)); + smartlist_free(chunks); + } + tor_free(family_line); + tor_free(onion_pkey); + tor_free(identity_pkey); + tor_free(extra_or_address); + + return output; } /** Copy the primary (IPv4) OR port (IP address and TCP port) for diff --git a/src/or/router.h b/src/or/router.h index fd2076a..7a09301 100644 --- a/src/or/router.h +++ b/src/or/router.h @@ -90,8 +90,8 @@ int router_is_me(const routerinfo_t *router); int router_fingerprint_is_me(const char *fp); int router_pick_published_address(const or_options_t *options, uint32_t *addr); int router_rebuild_descriptor(int force); -int router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, - crypto_pk_t *ident_key); +char *router_dump_router_to_string(routerinfo_t *router, + crypto_pk_t *ident_key); void router_get_prim_orport(const routerinfo_t *router, tor_addr_port_t *addr_port_out); void router_get_pref_orport(const routerinfo_t *router, diff --git a/src/test/test_dir.c b/src/test/test_dir.c index fbd49b7..ea0011a 100644 --- a/src/test/test_dir.c +++ b/src/test/test_dir.c @@ -73,7 +73,8 @@ test_dir_nicknames(void) static void test_dir_formats(void) { - char buf[8192], buf2[8192]; + char *buf = NULL; + char buf2[8192]; char platform[256]; char fingerprint[FINGERPRINT_LEN+1]; char *pk1_str = NULL, *pk2_str = NULL, *pk3_str = NULL, *cp; @@ -142,8 +143,8 @@ test_dir_formats(void) test_assert(!crypto_pk_write_public_key_to_string(pk3 , &pk3_str, &pk3_str_len)); - memset(buf, 0, 2048); - test_assert(router_dump_router_to_string(buf, 2048, r1, pk2)>0); + buf = router_dump_router_to_string(r1, pk2); + test_assert(buf); strlcpy(buf2, "router Magri 18.244.0.1 9000 0 9003\n" "or-address [1:2:3:4::]:9999\n" @@ -170,8 +171,10 @@ test_dir_formats(void) * twice */ test_streq(buf, buf2); + tor_free(buf); - test_assert(router_dump_router_to_string(buf, 2048, r1, pk2)>0); + buf = router_dump_router_to_string(r1, pk2); + test_assert(buf); cp = buf; rp1 = router_parse_entry_from_string((const char*)cp,NULL,1,0,NULL); test_assert(rp1); @@ -232,6 +235,7 @@ test_dir_formats(void) if (r2) routerinfo_free(r2); + tor_free(buf); tor_free(pk1_str); tor_free(pk2_str); tor_free(pk3_str);