[tor-commits] [tor/master] addr: Make resolve_my_address_v4() use find_my_address()

dgoulet at torproject.org dgoulet at torproject.org
Wed Jun 24 17:58:40 UTC 2020


commit b8042c9d9a44eaf78c5580a1b0a3d15a90f125ce
Author: David Goulet <dgoulet at torproject.org>
Date:   Thu Jun 18 16:07:22 2020 -0400

    addr: Make resolve_my_address_v4() use find_my_address()
    
    In order to transition smoothly, maek resolve_my_address_v4() call the new
    fancy find_my_address() with AF_INET.
    
    Next commits should remove the use of resolve_my_address_v4() accross the code
    to use find_my_address().
    
    This commit is so the unit tests would be more easily fixed and port to the
    new find_my_address() internals.
    
    Part of #33233.
    
    Signed-off-by: David Goulet <dgoulet at torproject.org>
---
 src/app/config/resolve_addr.c | 198 ++----------------------------------------
 src/test/test_config.c        | 126 ++++++++++++---------------
 2 files changed, 60 insertions(+), 264 deletions(-)

diff --git a/src/app/config/resolve_addr.c b/src/app/config/resolve_addr.c
index 5cabb5889..9a7fbde16 100644
--- a/src/app/config/resolve_addr.c
+++ b/src/app/config/resolve_addr.c
@@ -579,200 +579,14 @@ resolve_my_address_v4(int warn_severity, const or_options_t *options,
                       uint32_t *addr_out,
                       const char **method_out, char **hostname_out)
 {
-  struct in_addr in;
-  uint32_t addr; /* host order */
-  char hostname[256];
-  const char *method_used;
-  const char *hostname_used;
-  int explicit_ip=1;
-  int explicit_hostname=1;
-  int from_interface=0;
-  char *addr_string = NULL;
-  int notice_severity = warn_severity <= LOG_NOTICE ?
-    LOG_NOTICE : warn_severity;
-
-  tor_addr_t myaddr;
-  tor_assert(addr_out);
-
-  /*
-   * Step one: Fill in 'hostname' to be our best guess.
-   */
-
-  if (options->Address) {
-    /* Only 1 Address is supported even though this is a list. */
-    strlcpy(hostname, options->Address->value, sizeof(hostname));
-    log_debug(LD_CONFIG, "Trying configured Address '%s' as local hostname",
-              hostname);
-  } else { /* then we need to guess our address */
-    explicit_ip = 0; /* it's implicit */
-    explicit_hostname = 0; /* it's implicit */
-
-    if (tor_gethostname(hostname, sizeof(hostname)) < 0) {
-      log_fn(warn_severity, LD_NET,"Error obtaining local hostname");
-      return -1;
-    }
-    log_debug(LD_CONFIG, "Guessed local host name as '%s'", hostname);
-  }
-
-  /*
-   * Step two: Now that we know 'hostname', parse it or resolve it. If
-   * it doesn't parse or resolve, look at the interface address. Set 'addr'
-   * to be our (host-order) 32-bit answer.
-   */
-
-  if (tor_inet_aton(hostname, &in) == 0) {
-    /* then we have to resolve it */
-    log_debug(LD_CONFIG, "Local hostname '%s' is DNS address. "
-              "Trying to resolve to IP address.", hostname);
-    explicit_ip = 0;
-    if (tor_lookup_hostname(hostname, &addr)) { /* failed to resolve */
-      uint32_t interface_ip; /* host order */
-
-      if (explicit_hostname) {
-        log_fn(warn_severity, LD_CONFIG,
-               "Could not resolve local Address '%s'. Failing.", hostname);
-        return -1;
-      }
-      log_fn(notice_severity, LD_CONFIG,
-             "Could not resolve guessed local hostname '%s'. "
-             "Trying something else.", hostname);
-      if (get_interface_address(warn_severity, &interface_ip)) {
-        log_fn(warn_severity, LD_CONFIG,
-               "Could not get local interface IP address. Failing.");
-        return -1;
-      }
-      from_interface = 1;
-      addr = interface_ip;
-      log_fn(notice_severity, LD_CONFIG, "Learned IP address '%s' for "
-             "local interface. Using that.", fmt_addr32(addr));
-      strlcpy(hostname, "<guessed from interfaces>", sizeof(hostname));
-    } else { /* resolved hostname into addr */
-      tor_addr_from_ipv4h(&myaddr, addr);
-
-      if (!explicit_hostname &&
-          tor_addr_is_internal(&myaddr, 0)) {
-        tor_addr_t interface_ip;
-
-        log_fn(notice_severity, LD_CONFIG, "Guessed local hostname '%s' "
-               "resolves to a private IP address (%s). Trying something "
-               "else.", hostname, fmt_addr32(addr));
-
-        if (get_interface_address6(warn_severity, AF_INET, &interface_ip)<0) {
-          log_fn(warn_severity, LD_CONFIG,
-                 "Could not get local interface IP address. Too bad.");
-        } else if (tor_addr_is_internal(&interface_ip, 0)) {
-          log_fn(notice_severity, LD_CONFIG,
-                 "Interface IP address '%s' is a private address too. "
-                 "Ignoring.", fmt_addr(&interface_ip));
-        } else {
-          from_interface = 1;
-          addr = tor_addr_to_ipv4h(&interface_ip);
-          log_fn(notice_severity, LD_CONFIG,
-                 "Learned IP address '%s' for local interface."
-                 " Using that.", fmt_addr32(addr));
-          strlcpy(hostname, "<guessed from interfaces>", sizeof(hostname));
-        }
-      }
-    }
-  } else {
-    log_debug(LD_CONFIG, "Local hostname '%s' is already IP address, "
-              "skipping DNS resolution", hostname);
-    addr = ntohl(in.s_addr); /* set addr so that addr_string is not
-                              * illformed */
-  }
-
-  /*
-   * Step three: Check whether 'addr' is an internal IP address, and error
-   * out if it is and we don't want that.
-   */
-
-  tor_addr_from_ipv4h(&myaddr,addr);
-
-  addr_string = tor_dup_ip(addr);
-  if (addr_string && tor_addr_is_internal(&myaddr, 0)) {
-    /* make sure we're ok with publishing an internal IP */
-    if (using_default_dir_authorities(options)) {
-      /* if they are using the default authorities, disallow internal IPs
-       * always. For IPv6 ORPorts, this check is done in
-       * router_get_advertised_ipv6_or_ap(). See #33681. */
-      log_fn(warn_severity, LD_CONFIG,
-             "Address '%s' resolves to private IP address '%s'. "
-             "Tor servers that use the default DirAuthorities must have "
-             "public IP addresses.", hostname, addr_string);
-      tor_free(addr_string);
-      return -1;
-    }
-    if (!explicit_ip) {
-      /* even if they've set their own authorities, require an explicit IP if
-       * they're using an internal address. */
-      log_fn(warn_severity, LD_CONFIG, "Address '%s' resolves to private "
-             "IP address '%s'. Please set the Address config option to be "
-             "the IP address you want to use.", hostname, addr_string);
-      tor_free(addr_string);
-      return -1;
-    }
-  }
-
-  /*
-   * Step four: We have a winner! 'addr' is our answer for sure, and
-   * 'addr_string' is its string form. Fill out the various fields to
-   * say how we decided it.
-   */
-
-  log_debug(LD_CONFIG, "Resolved Address to '%s'.", addr_string);
-
-  if (explicit_ip) {
-    method_used = "CONFIGURED";
-    hostname_used = NULL;
-  } else if (explicit_hostname) {
-    method_used = "RESOLVED";
-    hostname_used = hostname;
-  } else if (from_interface) {
-    method_used = "INTERFACE";
-    hostname_used = NULL;
-  } else {
-    method_used = "GETHOSTNAME";
-    hostname_used = hostname;
-  }
-
-  *addr_out = addr;
-  if (method_out)
-    *method_out = method_used;
-  if (hostname_out)
-    *hostname_out = hostname_used ? tor_strdup(hostname_used) : NULL;
-
-  /*
-   * Step five: Check if the answer has changed since last time (or if
-   * there was no last time), and if so call various functions to keep
-   * us up-to-date.
-   */
-
-  if (last_resolved_addr_v4 && last_resolved_addr_v4 != *addr_out) {
-    /* Leave this as a notice, regardless of the requested severity,
-     * at least until dynamic IP address support becomes bulletproof. */
-    log_notice(LD_NET,
-               "Your IP address seems to have changed to %s "
-               "(METHOD=%s%s%s). Updating.",
-               addr_string, method_used,
-               hostname_used ? " HOSTNAME=" : "",
-               hostname_used ? hostname_used : "");
-    ip_address_changed(0);
-  }
-
-  if (last_resolved_addr_v4 != *addr_out) {
-    control_event_server_status(LOG_NOTICE,
-                                "EXTERNAL_ADDRESS ADDRESS=%s METHOD=%s%s%s",
-                                addr_string, method_used,
-                                hostname_used ? " HOSTNAME=" : "",
-                                hostname_used ? hostname_used : "");
+  tor_addr_t my_addr;
+  bool ret = find_my_address(options, AF_INET, warn_severity, &my_addr,
+                             method_out, hostname_out);
+  if (!ret) {
+    return -1;
   }
-  last_resolved_addr_v4 = *addr_out;
-
-  /*
-   * And finally, clean up and return success.
-   */
 
-  tor_free(addr_string);
+  *addr_out = tor_addr_to_ipv4h(&my_addr);
   return 0;
 }
 
diff --git a/src/test/test_config.c b/src/test/test_config.c
index 87104113b..a6b02713f 100644
--- a/src/test/test_config.c
+++ b/src/test/test_config.c
@@ -990,52 +990,55 @@ test_config_fix_my_family(void *arg)
 
 static int n_hostname_01010101 = 0;
 
-/** This mock function is meant to replace tor_lookup_hostname().
+/** This mock function is meant to replace tor_addr_lookup().
  * It answers with 1.1.1.1 as IP adddress that resulted from lookup.
  * This function increments <b>n_hostname_01010101</b> counter by one
  * every time it is called.
  */
 static int
-tor_lookup_hostname_01010101(const char *name, uint32_t *addr)
+tor_addr_lookup_01010101(const char *name, uint16_t family, tor_addr_t *addr)
 {
   n_hostname_01010101++;
 
-  if (name && addr) {
-    *addr = ntohl(0x01010101);
+  if (family == AF_INET) {
+    if (name && addr) {
+      tor_addr_from_ipv4h(addr, 0x01010101);
+    }
   }
-
   return 0;
 }
 
 static int n_hostname_localhost = 0;
 
-/** This mock function is meant to replace tor_lookup_hostname().
+/** This mock function is meant to replace tor_addr_lookup().
  * It answers with 127.0.0.1 as IP adddress that resulted from lookup.
  * This function increments <b>n_hostname_localhost</b> counter by one
  * every time it is called.
  */
 static int
-tor_lookup_hostname_localhost(const char *name, uint32_t *addr)
+tor_addr_lookup_localhost(const char *name, uint16_t family, tor_addr_t *addr)
 {
   n_hostname_localhost++;
 
-  if (name && addr) {
-    *addr = 0x7f000001;
+  if (family == AF_INET) {
+    if (name && addr) {
+      tor_addr_from_ipv4h(addr, 0x7f000001);
+    }
   }
-
   return 0;
 }
 
 static int n_hostname_failure = 0;
 
-/** This mock function is meant to replace tor_lookup_hostname().
+/** This mock function is meant to replace tor_addr_lookup().
  * It pretends to fail by returning -1 to caller. Also, this function
  * increments <b>n_hostname_failure</b> every time it is called.
  */
 static int
-tor_lookup_hostname_failure(const char *name, uint32_t *addr)
+tor_addr_lookup_failure(const char *name, uint16_t family, tor_addr_t *addr)
 {
   (void)name;
+  (void)family;
   (void)addr;
 
   n_hostname_failure++;
@@ -1097,29 +1100,29 @@ tor_gethostname_failure(char *name, size_t namelen)
   return -1;
 }
 
-static int n_get_interface_address = 0;
+static int n_get_interface_address6 = 0;
+static sa_family_t last_address6_family;
 
 /** This mock function is meant to replace get_interface_address().
  * It answers with address 8.8.8.8. This function increments
  * <b>n_get_interface_address</b> by one every time it is called.
  */
 static int
-get_interface_address_08080808(int severity, uint32_t *addr)
+get_interface_address6_08080808(int severity, sa_family_t family,
+                                tor_addr_t *addr)
 {
   (void)severity;
 
-  n_get_interface_address++;
+  n_get_interface_address6++;
 
-  if (addr) {
-    *addr = ntohl(0x08080808);
+  if (family == AF_INET) {
+    if (addr) {
+      tor_addr_from_ipv4h(addr, 0x08080808);
+    }
   }
-
   return 0;
 }
 
-static int n_get_interface_address6 = 0;
-static sa_family_t last_address6_family;
-
 /** This mock function is meant to replace get_interface_address6().
  * It answers with IP address 9.9.9.9 iff both of the following are true:
  *  - <b>family</b> is AF_INET
@@ -1145,25 +1148,6 @@ get_interface_address6_replacement(int severity, sa_family_t family,
   return 0;
 }
 
-static int n_get_interface_address_failure = 0;
-
-/**
- * This mock function is meant to replace get_interface_address().
- * It pretends to fail getting interface address by returning -1.
- * <b>n_get_interface_address_failure</b> is incremented by one
- * every time this function is called.
- */
-static int
-get_interface_address_failure(int severity, uint32_t *addr)
-{
-  (void)severity;
-  (void)addr;
-
-  n_get_interface_address_failure++;
-
-  return -1;
-}
-
 static int n_get_interface_address6_failure = 0;
 
 /**
@@ -1200,8 +1184,6 @@ test_config_resolve_my_address_v4(void *arg)
   int prev_n_gethostname_replacement;
   int prev_n_gethostname_failure;
   int prev_n_gethostname_localhost;
-  int prev_n_get_interface_address;
-  int prev_n_get_interface_address_failure;
   int prev_n_get_interface_address6;
   int prev_n_get_interface_address6_failure;
 
@@ -1225,18 +1207,18 @@ test_config_resolve_my_address_v4(void *arg)
   tt_want(retval == 0);
   tt_want_str_op(method_used,OP_EQ,"CONFIGURED");
   tt_want(hostname_out == NULL);
-  tt_assert(resolved_addr == 0x80348069);
+  tt_u64_op(resolved_addr, OP_EQ, 0x80348069);
 
   config_free_lines(options->Address);
 
 /*
  * CASE 2:
  * If options->Address is a valid DNS address, we want resolve_my_address_v4()
- * function to ask tor_lookup_hostname() for help with resolving it
+ * function to ask tor_addr_lookup() for help with resolving it
  * and return the address that was resolved (in host order).
  */
 
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_01010101);
+  MOCK(tor_addr_lookup, tor_addr_lookup_01010101);
 
   strlcpy(buf, "Address www.torproject.org\n", sizeof(buf));
   config_get_lines(buf, &(options->Address), 0);
@@ -1250,9 +1232,9 @@ test_config_resolve_my_address_v4(void *arg)
   tt_want(n_hostname_01010101 == prev_n_hostname_01010101 + 1);
   tt_want_str_op(method_used,OP_EQ,"RESOLVED");
   tt_want_str_op(hostname_out,OP_EQ,"www.torproject.org");
-  tt_assert(resolved_addr == 0x01010101);
+  tt_u64_op(resolved_addr, OP_EQ, 0x01010101);
 
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
 
   config_free_lines(options->Address);
   tor_free(hostname_out);
@@ -1261,14 +1243,14 @@ test_config_resolve_my_address_v4(void *arg)
  * CASE 3:
  * Given that options->Address is NULL, we want resolve_my_address_v4()
  * to try and use tor_gethostname() to get hostname AND use
- * tor_lookup_hostname() to get IP address.
+ * tor_addr_lookup() to get IP address.
  */
 
   resolved_addr = 0;
   options->Address = NULL;
 
   MOCK(tor_gethostname,tor_gethostname_replacement);
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_01010101);
+  MOCK(tor_addr_lookup,tor_addr_lookup_01010101);
 
   prev_n_gethostname_replacement = n_gethostname_replacement;
   prev_n_hostname_01010101 = n_hostname_01010101;
@@ -1284,7 +1266,7 @@ test_config_resolve_my_address_v4(void *arg)
   tt_assert(resolved_addr == 0x01010101);
 
   UNMOCK(tor_gethostname);
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
 
   tor_free(hostname_out);
 
@@ -1313,7 +1295,7 @@ test_config_resolve_my_address_v4(void *arg)
  * cannot be resolved.
  */
 
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_failure);
+  MOCK(tor_addr_lookup,tor_addr_lookup_failure);
 
   prev_n_hostname_failure = n_hostname_failure;
 
@@ -1326,7 +1308,7 @@ test_config_resolve_my_address_v4(void *arg)
   tt_want(n_hostname_failure == prev_n_hostname_failure + 1);
   tt_int_op(retval, OP_EQ, -1);
 
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
 
   config_free_lines(options->Address);
   options->Address = NULL;
@@ -1359,20 +1341,20 @@ test_config_resolve_my_address_v4(void *arg)
  */
 
   MOCK(tor_gethostname,tor_gethostname_replacement);
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_failure);
-  MOCK(get_interface_address,get_interface_address_08080808);
+  MOCK(tor_addr_lookup,tor_addr_lookup_failure);
+  MOCK(get_interface_address6, get_interface_address6_08080808);
 
   prev_n_gethostname_replacement = n_gethostname_replacement;
-  prev_n_get_interface_address = n_get_interface_address;
+  prev_n_get_interface_address6 = n_get_interface_address6;
 
   retval = resolve_my_address_v4(LOG_NOTICE,options,&resolved_addr,
-                              &method_used,&hostname_out);
+                                 &method_used,&hostname_out);
 
   tt_want(retval == 0);
   tt_want_int_op(n_gethostname_replacement, OP_EQ,
                  prev_n_gethostname_replacement + 1);
-  tt_want_int_op(n_get_interface_address, OP_EQ,
-                 prev_n_get_interface_address + 1);
+  tt_want_int_op(n_get_interface_address6, OP_EQ,
+                 prev_n_get_interface_address6 + 1);
   tt_want_str_op(method_used,OP_EQ,"INTERFACE");
   tt_want(hostname_out == NULL);
   tt_assert(resolved_addr == 0x08080808);
@@ -1387,16 +1369,16 @@ test_config_resolve_my_address_v4(void *arg)
  * get_interface_address() fails.
  */
 
-  MOCK(get_interface_address,get_interface_address_failure);
+  MOCK(get_interface_address6, get_interface_address6_failure);
 
-  prev_n_get_interface_address_failure = n_get_interface_address_failure;
+  prev_n_get_interface_address6_failure = n_get_interface_address6_failure;
   prev_n_gethostname_replacement = n_gethostname_replacement;
 
   retval = resolve_my_address_v4(LOG_NOTICE,options,&resolved_addr,
                               &method_used,&hostname_out);
 
-  tt_want(n_get_interface_address_failure ==
-          prev_n_get_interface_address_failure + 1);
+  tt_want(n_get_interface_address6_failure ==
+          prev_n_get_interface_address6_failure + 1);
   tt_want(n_gethostname_replacement ==
           prev_n_gethostname_replacement + 1);
   tt_int_op(retval, OP_EQ, -1);
@@ -1406,14 +1388,14 @@ test_config_resolve_my_address_v4(void *arg)
 
 /*
  * CASE 9:
- * Given that options->Address is NULL AND tor_lookup_hostname()
+ * Given that options->Address is NULL AND tor_addr_lookup()
  * fails AND hostname returned by gethostname() resolves
  * to local IP address, we want resolve_my_address_v4() function to
  * call get_interface_address6(.,AF_INET,.) and return IP address
  * the latter function has found.
  */
 
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_failure);
+  MOCK(tor_addr_lookup,tor_addr_lookup_failure);
   MOCK(tor_gethostname,tor_gethostname_replacement);
   MOCK(get_interface_address6,get_interface_address6_replacement);
 
@@ -1432,7 +1414,7 @@ test_config_resolve_my_address_v4(void *arg)
   tt_want_str_op(method_used,OP_EQ,"INTERFACE");
   tt_assert(resolved_addr == 0x09090909);
 
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
   UNMOCK(tor_gethostname);
   UNMOCK(get_interface_address6);
 
@@ -1444,11 +1426,11 @@ test_config_resolve_my_address_v4(void *arg)
    *   1. options->Address is not NULL
    *   2. ... but it cannot be converted to struct in_addr by
    *      tor_inet_aton()
-   *   3. ... and tor_lookup_hostname() fails to resolve the
+   *   3. ... and tor_addr_lookup() fails to resolve the
    *      options->Address
    */
 
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_failure);
+  MOCK(tor_addr_lookup, tor_addr_lookup_failure);
 
   prev_n_hostname_failure = n_hostname_failure;
 
@@ -1462,7 +1444,7 @@ test_config_resolve_my_address_v4(void *arg)
   tt_int_op(retval, OP_EQ, -1);
 
   UNMOCK(tor_gethostname);
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
 
   tor_free(hostname_out);
 
@@ -1474,7 +1456,7 @@ test_config_resolve_my_address_v4(void *arg)
    *      if running on.
    *   3. Hostname from previous step cannot be converted to
    *      address by using tor_inet_aton() function.
-   *   4. However, tor_lookup_hostname() succeeds in resolving the
+   *   4. However, tor_addr_lookup() succeeds in resolving the
    *      hostname from step 2.
    *   5. Unfortunately, tor_addr_is_internal() deems this address
    *      to be internal.
@@ -1489,7 +1471,7 @@ test_config_resolve_my_address_v4(void *arg)
   options->Address = NULL;
 
   MOCK(tor_gethostname,tor_gethostname_replacement);
-  MOCK(tor_lookup_hostname,tor_lookup_hostname_localhost);
+  MOCK(tor_addr_lookup,tor_addr_lookup_localhost);
   MOCK(get_interface_address6,get_interface_address6_replacement);
 
   prev_n_gethostname_replacement = n_gethostname_replacement;
@@ -1533,7 +1515,7 @@ test_config_resolve_my_address_v4(void *arg)
   tt_int_op(retval, OP_EQ, -1);
 
   UNMOCK(tor_gethostname);
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
   UNMOCK(get_interface_address6);
 
   /* CASE 12:
@@ -1570,7 +1552,7 @@ test_config_resolve_my_address_v4(void *arg)
   tor_free(hostname_out);
 
   UNMOCK(tor_gethostname);
-  UNMOCK(tor_lookup_hostname);
+  UNMOCK(tor_addr_lookup);
   UNMOCK(get_interface_address);
   UNMOCK(get_interface_address6);
   UNMOCK(tor_gethostname);





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