Add unittests for the guardfraction feature.

src/test/include.am

@@ -40,6 +40,7 @@ src_test_test_SOURCES = \
 	src/test/test_dir.c \
 	src/test/test_entryconn.c \
 	src/test/test_entrynodes.c \
+	src/test/test_guardfraction.c \
 	src/test/test_extorport.c \
 	src/test/test_hs.c \
 	src/test/test_introduce.c \

src/test/test.c

@@ -1126,6 +1126,7 @@ extern struct testcase_t crypto_tests[];
 extern struct testcase_t dir_tests[];
 extern struct testcase_t entryconn_tests[];
 extern struct testcase_t entrynodes_tests[];
+extern struct testcase_t guardfraction_tests[];
 extern struct testcase_t extorport_tests[];
 extern struct testcase_t hs_tests[];
 extern struct testcase_t introduce_tests[];
@@ -1170,6 +1171,7 @@ struct testgroup_t testgroups[] = {
   { "dir/md/", microdesc_tests },
   { "entryconn/", entryconn_tests },
   { "entrynodes/", entrynodes_tests },
+  { "guardfraction/", guardfraction_tests },
   { "extorport/", extorport_tests },
   { "hs/", hs_tests },
   { "introduce/", introduce_tests },

src/test/test_guardfraction.c

@@ -0,0 +1,418 @@
+/* Copyright (c) 2014, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#define DIRSERV_PRIVATE
+#define ROUTERPARSE_PRIVATE
+#define NETWORKSTATUS_PRIVATE
+
+#include "orconfig.h"
+#include "or.h"
+#include "config.h"
+#include "dirserv.h"
+#include "container.h"
+#include "entrynodes.h"
+#include "util.h"
+#include "routerparse.h"
+#include "networkstatus.h"
+
+#include "test.h"
+#include "test_helpers.h"
+
+/* Generate a vote_routerstatus_t for a router with identity digest
+   <b>digest_in_hex</b>. */
+static vote_routerstatus_t *
+gen_vote_routerstatus_for_tests(const char *digest_in_hex, int is_guard)
+{
+  int retval;
+  vote_routerstatus_t *vrs = NULL;
+  routerstatus_t *rs;
+
+  vrs = tor_malloc_zero(sizeof(vote_routerstatus_t));
+  rs = &vrs->status;
+
+  { /* Useful information for tests */
+    char digest_tmp[DIGEST_LEN];
+
+    /* Guard or not? */
+    rs->is_possible_guard = is_guard;
+
+    /* Fill in the fpr */
+    tt_int_op(strlen(digest_in_hex), ==, HEX_DIGEST_LEN);
+    retval = base16_decode(digest_tmp, sizeof(digest_tmp),
+                           digest_in_hex, HEX_DIGEST_LEN);
+    tt_int_op(retval, ==, 0);
+    memcpy(rs->identity_digest, digest_tmp, DIGEST_LEN);
+  }
+
+  { /* Misc info (maybe not used in tests) */
+    vrs->version = tor_strdup("0.1.2.14");
+    strlcpy(rs->nickname, "router2", sizeof(rs->nickname));
+    memset(rs->descriptor_digest, 78, DIGEST_LEN);
+    rs->addr = 0x99008801;
+    rs->or_port = 443;
+    rs->dir_port = 8000;
+    /* all flags but running cleared */
+    rs->is_flagged_running = 1;
+    vrs->has_measured_bw = 1;
+    rs->has_bandwidth = 1;
+  }
+
+  return vrs;
+
+ done:
+  vote_routerstatus_free(vrs);
+
+  return NULL;
+}
+
+/** Make sure our parsers reject corrupted guardfraction files. */
+static void
+test_parse_guardfraction_file_bad(void *arg)
+{
+  int retval;
+  char *guardfraction_bad = NULL;
+  const char *yesterday_date_str = get_yesterday_date_str();
+
+  (void) arg;
+
+  /* Start parsing all those corrupted guardfraction files! */
+
+  /* Guardfraction file version is not a number! */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version nan\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 100 420\n"
+               "guard-seen 07B5547026DF3E229806E135CFA8552D56AFBABC 5 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, -1);
+  tor_free(guardfraction_bad);
+
+  /* This one does not have a date! Parsing should fail. */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at not_date\n"
+               "n-inputs 420 3\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 100 420\n"
+               "guard-seen 07B5547026DF3E229806E135CFA8552D56AFBABC 5 420\n");
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, -1);
+  tor_free(guardfraction_bad);
+
+  /* This one has an incomplete n-inputs line, but parsing should
+     still continue. */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs biggie\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 100 420\n"
+               "guard-seen 07B5547026DF3E229806E135CFA8552D56AFBABC 5 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, 2);
+  tor_free(guardfraction_bad);
+
+  /* This one does not have a fingerprint in the guard line! */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen not_a_fingerprint 100 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, 0);
+  tor_free(guardfraction_bad);
+
+  /* This one does not even have an integer guardfraction value. */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 NaN 420\n"
+               "guard-seen 07B5547026DF3E229806E135CFA8552D56AFBABC 5 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, 1);
+  tor_free(guardfraction_bad);
+
+  /* This one is not a percentage (not in [0, 100]) */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 666 420\n"
+               "guard-seen 07B5547026DF3E229806E135CFA8552D56AFBABC 5 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, 1);
+  tor_free(guardfraction_bad);
+
+  /* This one is not a percentage either (not in [0, 100]) */
+  tor_asprintf(&guardfraction_bad,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777 -3 420\n",
+               yesterday_date_str);
+
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_bad, NULL);
+  tt_int_op(retval, ==, 0);
+
+ done:
+  tor_free(guardfraction_bad);
+}
+
+/* Make sure that our test guardfraction file gets parsed properly, and
+ * its information are applied properly to our routerstatuses. */
+static void
+test_parse_guardfraction_file_good(void *arg)
+{
+  int retval;
+  vote_routerstatus_t *vrs_guard = NULL;
+  vote_routerstatus_t *vrs_dummy = NULL;
+  char *guardfraction_good = NULL;
+  const char *yesterday_date_str = get_yesterday_date_str();
+  smartlist_t *routerstatuses = smartlist_new();
+
+  /* Some test values that we need to validate later */
+  const char fpr_guard[] = "D0EDB47BEAD32D26D0A837F7D5357EC3AD3B8777";
+  const char fpr_unlisted[] = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+  const int guardfraction_value = 42;
+
+  (void) arg;
+
+  {
+    /* Populate the smartlist with some fake routerstatuses, so that
+       after parsing the guardfraction file we can check that their
+       elements got filled properly. */
+
+    /* This one is a guard */
+    vrs_guard = gen_vote_routerstatus_for_tests(fpr_guard, 1);
+    tt_assert(vrs_guard);
+    smartlist_add(routerstatuses, vrs_guard);
+
+    /* This one is a guard but it's not in the guardfraction file */
+    vrs_dummy = gen_vote_routerstatus_for_tests(fpr_unlisted, 1);
+    tt_assert(vrs_dummy);
+    smartlist_add(routerstatuses, vrs_dummy);
+  }
+
+  tor_asprintf(&guardfraction_good,
+               "guardfraction-file-version 1\n"
+               "written-at %s\n"
+               "n-inputs 420 3\n"
+               "guard-seen %s %d 420\n",
+               yesterday_date_str,
+               fpr_guard, guardfraction_value);
+
+  /* Read the guardfraction file */
+  retval = dirserv_read_guardfraction_file_from_str(guardfraction_good,
+                                                    routerstatuses);
+  tt_int_op(retval, ==, 1);
+
+  { /* Test that routerstatus fields got filled properly */
+
+    /* The guardfraction fields of the guard should be filled. */
+    tt_assert(vrs_guard->status.has_guardfraction);
+    tt_int_op(vrs_guard->status.guardfraction_percentage,
+              ==,
+              guardfraction_value);
+
+    /* The guard that was not in the guardfraction file should not have
+       been touched either. */
+    tt_assert(!vrs_dummy->status.has_guardfraction);
+  }
+
+ done:
+  vote_routerstatus_free(vrs_guard);
+  vote_routerstatus_free(vrs_dummy);
+  smartlist_free(routerstatuses);
+  tor_free(guardfraction_good);
+}
+
+/** Make sure that the guardfraction bandwidths get calculated properly. */
+static void
+test_get_guardfraction_bandwidth(void *arg)
+{
+  guardfraction_bandwidth_t gf_bw;
+  const int orig_bw = 1000;
+
+  (void) arg;
+
+  /* A guard with bandwidth 1000 and GuardFraction 0.25, should have
+     bandwidth 250 as a guard and bandwidth 750 as a non-guard.  */
+  guard_get_guardfraction_bandwidth(&gf_bw,
+                                    orig_bw, 25);
+
+  tt_int_op(gf_bw.guard_bw, ==, 250);
+  tt_int_op(gf_bw.non_guard_bw, ==, 750);
+
+  /* Also check the 'guard_bw + non_guard_bw == original_bw'
+   * invariant. */
+  tt_int_op(gf_bw.non_guard_bw + gf_bw.guard_bw, ==, orig_bw);
+
+ done:
+  ;
+}
+
+/** Parse the GuardFraction element of the consensus, and make sure it
+ *  gets parsed correctly. */
+static void
+test_parse_guardfraction_consensus(void *arg)
+{
+  int retval;
+  or_options_t *options = get_options_mutable();
+
+  const char *guardfraction_str_good = "GuardFraction=66";
+  routerstatus_t rs_good;
+  routerstatus_t rs_no_guard;
+
+  const char *guardfraction_str_bad1 = "GuardFraction="; /* no value */
+  routerstatus_t rs_bad1;
+
+  const char *guardfraction_str_bad2 = "GuardFraction=166"; /* no percentage */
+  routerstatus_t rs_bad2;
+
+  (void) arg;
+
+  /* GuardFraction use is currently disabled by default. So we need to
+     manually enable it. */
+  options->UseGuardFraction = 1;
+
+  { /* Properly formatted GuardFraction. Check that it gets applied
+       correctly. */
+    memset(&rs_good, 0, sizeof(routerstatus_t));
+    rs_good.is_possible_guard = 1;
+
+    retval = routerstatus_parse_guardfraction(guardfraction_str_good,
+                                              NULL, NULL,
+                                              &rs_good);
+    tt_int_op(retval, ==, 0);
+    tt_assert(rs_good.has_guardfraction);
+    tt_int_op(rs_good.guardfraction_percentage, ==, 66);
+  }
+
+  { /* Properly formatted GuardFraction but router is not a
+       guard. GuardFraction should not get applied. */
+    memset(&rs_no_guard, 0, sizeof(routerstatus_t));
+    tt_assert(!rs_no_guard.is_possible_guard);
+
+    retval = routerstatus_parse_guardfraction(guardfraction_str_good,
+                                              NULL, NULL,
+                                              &rs_no_guard);
+    tt_int_op(retval, ==, 0);
+    tt_assert(!rs_no_guard.has_guardfraction);
+  }
+
+  { /* Bad GuardFraction. Function should fail and not apply. */
+    memset(&rs_bad1, 0, sizeof(routerstatus_t));
+    rs_bad1.is_possible_guard = 1;
+
+    retval = routerstatus_parse_guardfraction(guardfraction_str_bad1,
+                                              NULL, NULL,
+                                              &rs_bad1);
+    tt_int_op(retval, ==, -1);
+    tt_assert(!rs_bad1.has_guardfraction);
+  }
+
+  { /* Bad GuardFraction. Function should fail and not apply. */
+    memset(&rs_bad2, 0, sizeof(routerstatus_t));
+    rs_bad2.is_possible_guard = 1;
+
+    retval = routerstatus_parse_guardfraction(guardfraction_str_bad2,
+                                              NULL, NULL,
+                                              &rs_bad2);
+    tt_int_op(retval, ==, -1);
+    tt_assert(!rs_bad2.has_guardfraction);
+  }
+
+ done:
+  ;
+}
+
+/* Make sure that we use GuardFraction information when we should,
+   according to the torrc option and consensus parameter. */
+static void
+test_should_apply_guardfraction(void *arg)
+{
+  networkstatus_t vote_enabled, vote_disabled, vote_missing;
+  or_options_t *options = get_options_mutable();
+
+  (void) arg;
+
+  { /* Fill the votes for later */
+    /* This one suggests enabled GuardFraction. */
+    memset(&vote_enabled, 0, sizeof(vote_enabled));
+    vote_enabled.net_params = smartlist_new();
+    smartlist_split_string(vote_enabled.net_params,
+                           "UseGuardFraction=1", NULL, 0, 0);
+
+    /* This one suggests disabled GuardFraction. */
+    memset(&vote_disabled, 0, sizeof(vote_disabled));
+    vote_disabled.net_params = smartlist_new();
+    smartlist_split_string(vote_disabled.net_params,
+                           "UseGuardFraction=0", NULL, 0, 0);
+
+    /* This one doesn't have GuardFraction at all. */
+    memset(&vote_missing, 0, sizeof(vote_missing));
+    vote_missing.net_params = smartlist_new();
+    smartlist_split_string(vote_missing.net_params,
+                           "leon=trout", NULL, 0, 0);
+  }
+
+  /* If torrc option is set to yes, we should always use
+   * guardfraction.*/
+  options->UseGuardFraction = 1;
+  tt_int_op(should_apply_guardfraction(&vote_disabled), ==, 1);
+
+  /* If torrc option is set to no, we should never use
+   * guardfraction.*/
+  options->UseGuardFraction = 0;
+  tt_int_op(should_apply_guardfraction(&vote_enabled), ==, 0);
+
+  /* Now let's test torrc option set to auto. */
+  options->UseGuardFraction = -1;
+
+  /* If torrc option is set to auto, and consensus parameter is set to
+   * yes, we should use guardfraction. */
+  tt_int_op(should_apply_guardfraction(&vote_enabled), ==, 1);
+
+  /* If torrc option is set to auto, and consensus parameter is set to
+   * no, we should use guardfraction. */
+  tt_int_op(should_apply_guardfraction(&vote_disabled), ==, 0);
+
+  /* If torrc option is set to auto, and consensus parameter is not
+   * set, we should fallback to "no". */
+  tt_int_op(should_apply_guardfraction(&vote_missing), ==, 0);
+
+ done:
+  SMARTLIST_FOREACH(vote_enabled.net_params, char *, cp, tor_free(cp));
+  SMARTLIST_FOREACH(vote_disabled.net_params, char *, cp, tor_free(cp));
+  SMARTLIST_FOREACH(vote_missing.net_params, char *, cp, tor_free(cp));
+  smartlist_free(vote_enabled.net_params);
+  smartlist_free(vote_disabled.net_params);
+  smartlist_free(vote_missing.net_params);
+}
+
+struct testcase_t guardfraction_tests[] = {
+  { "parse_guardfraction_file_bad", test_parse_guardfraction_file_bad,
+    TT_FORK, NULL, NULL },
+  { "parse_guardfraction_file_good", test_parse_guardfraction_file_good,
+    TT_FORK, NULL, NULL },
+  { "parse_guardfraction_consensus", test_parse_guardfraction_consensus,
+    TT_FORK, NULL, NULL },
+  { "get_guardfraction_bandwidth", test_get_guardfraction_bandwidth,
+    TT_FORK, NULL, NULL },
+  { "should_apply_guardfraction", test_should_apply_guardfraction,
+    TT_FORK, NULL, NULL },
+
+  END_OF_TESTCASES
+};
+