commit 0417dae5808ddf86aed3a9b9a6883fa8f0922d2e Author: teor <teor2345@gmail.com> Date: Fri Dec 16 22:34:42 2016 +1100 When IPv6 addresses have not been downloaded, use hard-coded address info The microdesc consensus does not contain any IPv6 addresses. When a client has a microdesc consensus but no microdescriptor, make it use the hard-coded IPv6 address for the node (if available). (Hard-coded addresses can come from authorities, fallback directories, or configured bridges.) If there is no hard-coded address, log a BUG message, and fail the connection attempt. (All existing code checks for a hard-coded address before choosing a node address.) Fixes 20996, fix on b167e82 from 19608 in 0.2.8.5-alpha. --- src/or/nodelist.c | 21 ++++++++++++++++----- src/or/policies.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- src/or/routerlist.c | 2 +- 3 files changed, 59 insertions(+), 8 deletions(-) diff --git a/src/or/nodelist.c b/src/or/nodelist.c index 3f2e111..b29f217 100644 --- a/src/or/nodelist.c +++ b/src/or/nodelist.c @@ -1126,6 +1126,9 @@ node_get_prim_orport(const node_t *node, tor_addr_port_t *ap_out) node_assert_ok(node); tor_assert(ap_out); + /* Check ri first, because rewrite_node_address_for_bridge() updates + * node->ri with the configured bridge address. */ + RETURN_IPV4_AP(node->ri, or_port, ap_out); RETURN_IPV4_AP(node->rs, or_port, ap_out); /* Microdescriptors only have an IPv6 address */ @@ -1156,9 +1159,11 @@ node_get_pref_ipv6_orport(const node_t *node, tor_addr_port_t *ap_out) node_assert_ok(node); tor_assert(ap_out); - /* Prefer routerstatus over microdesc for consistency with the - * fascist_firewall_* functions. Also check if the address or port are valid, - * and try another alternative if they are not. */ + /* Check ri first, because rewrite_node_address_for_bridge() updates + * node->ri with the configured bridge address. + * Prefer rs over md for consistency with the fascist_firewall_* functions. + * Check if the address or port are valid, and try another alternative + * if they are not. */ if (node->ri && tor_addr_port_is_valid(&node->ri->ipv6_addr, node->ri->ipv6_orport, 0)) { @@ -1218,6 +1223,9 @@ node_get_prim_dirport(const node_t *node, tor_addr_port_t *ap_out) node_assert_ok(node); tor_assert(ap_out); + /* Check ri first, because rewrite_node_address_for_bridge() updates + * node->ri with the configured bridge address. */ + RETURN_IPV4_AP(node->ri, dir_port, ap_out); RETURN_IPV4_AP(node->rs, dir_port, ap_out); /* Microdescriptors only have an IPv6 address */ @@ -1250,8 +1258,11 @@ node_get_pref_ipv6_dirport(const node_t *node, tor_addr_port_t *ap_out) node_assert_ok(node); tor_assert(ap_out); - /* Check if the address or port are valid, and try another alternative if - * they are not. Note that microdescriptors have no dir_port. */ + /* Check ri first, because rewrite_node_address_for_bridge() updates + * node->ri with the configured bridge address. + * Prefer rs over md for consistency with the fascist_firewall_* functions. + * Check if the address or port are valid, and try another alternative + * if they are not. */ /* Assume IPv4 and IPv6 dirports are the same */ if (node->ri && tor_addr_port_is_valid(&node->ri->ipv6_addr, diff --git a/src/or/policies.c b/src/or/policies.c index dcee653..ac57e72 100644 --- a/src/or/policies.c +++ b/src/or/policies.c @@ -20,6 +20,7 @@ #include "or.h" #include "config.h" #include "dirserv.h" +#include "microdesc.h" #include "networkstatus.h" #include "nodelist.h" #include "policies.h" @@ -893,6 +894,33 @@ fascist_firewall_choose_address_ipv4h(uint32_t ipv4h_addr, pref_ipv6, ap); } +/* The microdescriptor consensus has no IPv6 addresses in rs: they are in + * the microdescriptors. This means we can't rely on the node's IPv6 address + * until its microdescriptor is available (when using microdescs). + * But for bridges, rewrite_node_address_for_bridge() updates node->ri with + * the configured address, so we can trust bridge addresses. + * (Bridges could gain an IPv6 address if their microdescriptor arrives, but + * this will never be their preferred address: that is in the config.) + * Returns true if the node needs a microdescriptor for its IPv6 address, and + * false if the addresses in the node are already up-to-date. + */ +static int +node_awaiting_ipv6(const or_options_t* options, const node_t *node) +{ + tor_assert(node); + + /* There's no point waiting for an IPv6 address if we'd never use it */ + if (!fascist_firewall_use_ipv6(options)) { + return 0; + } + + /* We are waiting if we_use_microdescriptors_for_circuits() and we have no + * md. Bridges have a ri based on their config. They would never use the + * address from their md, so there's no need to wait for it. */ + return (!node->md && we_use_microdescriptors_for_circuits(options) && + !node->ri); +} + /** Like fascist_firewall_choose_address_base(), but takes <b>rs</b>. * Consults the corresponding node, then falls back to rs if node is NULL. * This should only happen when there's no valid consensus, and rs doesn't @@ -909,15 +937,15 @@ fascist_firewall_choose_address_rs(const routerstatus_t *rs, tor_assert(ap); + const or_options_t *options = get_options(); const node_t *node = node_get_by_id(rs->identity_digest); - if (node) { + if (node && !node_awaiting_ipv6(options, node)) { return fascist_firewall_choose_address_node(node, fw_connection, pref_only, ap); } else { /* There's no node-specific IPv6 preference, so use the generic IPv6 * preference instead. */ - const or_options_t *options = get_options(); int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION ? fascist_firewall_prefer_ipv6_orport(options) : fascist_firewall_prefer_ipv6_dirport(options)); @@ -951,6 +979,18 @@ fascist_firewall_choose_address_node(const node_t *node, node_assert_ok(node); + /* Calling fascist_firewall_choose_address_node() when the node is missing + * IPv6 information breaks IPv6-only clients. + * If the node is a hard-coded fallback directory or authority, call + * fascist_firewall_choose_address_rs() on the fake (hard-coded) routerstatus + * for the node. + * If it is not hard-coded, check that the node has a microdescriptor, full + * descriptor (routerinfo), or is one of our configured bridges before + * calling this function. */ + if (BUG(node_awaiting_ipv6(get_options(), node))) { + return 0; + } + const int pref_ipv6_node = (fw_connection == FIREWALL_OR_CONNECTION ? node_ipv6_or_preferred(node) : node_ipv6_dir_preferred(node)); diff --git a/src/or/routerlist.c b/src/or/routerlist.c index 6bac57d..0434195 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -948,7 +948,7 @@ authority_certs_fetch_resource_impl(const char *resource, /* If we've just downloaded a consensus from a bridge, re-use that * bridge */ - if (options->UseBridges && node && !get_via_tor) { + if (options->UseBridges && node && node->ri && !get_via_tor) { /* clients always make OR connections to bridges */ tor_addr_port_t or_ap; /* we are willing to use a non-preferred address if we need to */