Commit cc30c09f authored by George Kadianakis's avatar George Kadianakis
Browse files

Merge branch 'mr/236'

parents 1949afef fb3704b4
o Minor bugfixes (directory authorities, voting):
- Add a new consensus method (31) to support any future changes that
authorities decide to make to the value of bwweightscale or
maxunmeasuredbw. Previously, there was a bug that prevented the
authorities from parsing these consensus parameters correctly under
most circumstances.
Fixes bug 19011; bugfix on 0.2.2.10-alpha.
......@@ -1757,26 +1757,14 @@ networkstatus_compute_consensus(smartlist_t *votes,
}
{
char *max_unmeasured_param = NULL;
/* XXXX Extract this code into a common function. Or don't! see #19011 */
if (params) {
if (strcmpstart(params, "maxunmeasuredbw=") == 0)
max_unmeasured_param = params;
else
max_unmeasured_param = strstr(params, " maxunmeasuredbw=");
}
if (max_unmeasured_param) {
int ok = 0;
char *eq = strchr(max_unmeasured_param, '=');
if (eq) {
max_unmeasured_bw_kb = (uint32_t)
tor_parse_ulong(eq+1, 10, 1, UINT32_MAX, &ok, NULL);
if (!ok) {
log_warn(LD_DIR, "Bad element '%s' in max unmeasured bw param",
escaped(max_unmeasured_param));
max_unmeasured_bw_kb = DEFAULT_MAX_UNMEASURED_BW_KB;
}
}
if (consensus_method < MIN_METHOD_FOR_CORRECT_BWWEIGHTSCALE) {
max_unmeasured_bw_kb = (int32_t) extract_param_buggy(
params, "maxunmeasuredbw", DEFAULT_MAX_UNMEASURED_BW_KB);
} else {
max_unmeasured_bw_kb = dirvote_get_intermediate_param_value(
param_list, "maxunmeasurdbw", DEFAULT_MAX_UNMEASURED_BW_KB);
if (max_unmeasured_bw_kb < 1)
max_unmeasured_bw_kb = 1;
}
}
......@@ -2326,38 +2314,16 @@ networkstatus_compute_consensus(smartlist_t *votes,
smartlist_add_strdup(chunks, "directory-footer\n");
{
int64_t weight_scale = BW_WEIGHT_SCALE;
char *bw_weight_param = NULL;
// Parse params, extract BW_WEIGHT_SCALE if present
// DO NOT use consensus_param_bw_weight_scale() in this code!
// The consensus is not formed yet!
/* XXXX Extract this code into a common function. Or not: #19011. */
if (params) {
if (strcmpstart(params, "bwweightscale=") == 0)
bw_weight_param = params;
else
bw_weight_param = strstr(params, " bwweightscale=");
}
if (bw_weight_param) {
int ok=0;
char *eq = strchr(bw_weight_param, '=');
if (eq) {
weight_scale = tor_parse_long(eq+1, 10, 1, INT32_MAX, &ok,
NULL);
if (!ok) {
log_warn(LD_DIR, "Bad element '%s' in bw weight param",
escaped(bw_weight_param));
weight_scale = BW_WEIGHT_SCALE;
}
} else {
log_warn(LD_DIR, "Bad element '%s' in bw weight param",
escaped(bw_weight_param));
weight_scale = BW_WEIGHT_SCALE;
}
int64_t weight_scale;
if (consensus_method < MIN_METHOD_FOR_CORRECT_BWWEIGHTSCALE) {
weight_scale = extract_param_buggy(params, "bwweightscale",
BW_WEIGHT_SCALE);
} else {
weight_scale = dirvote_get_intermediate_param_value(
param_list, "bwweightscale", BW_WEIGHT_SCALE);
if (weight_scale < 1)
weight_scale = 1;
}
added_weights = networkstatus_compute_bw_weights_v10(chunks, G, M, E, D,
T, weight_scale);
}
......@@ -2459,6 +2425,53 @@ networkstatus_compute_consensus(smartlist_t *votes,
return result;
}
/** Extract the value of a parameter from a string encoding a list of
* parameters, badly.
*
* This is a deliberately buggy implementation, for backward compatibility
* with versions of Tor affected by #19011. Once all authorities have
* upgraded to consensus method 31 or later, then we can throw away this
* function. */
STATIC int64_t
extract_param_buggy(const char *params,
const char *param_name,
int64_t default_value)
{
int64_t value = default_value;
const char *param_str = NULL;
if (params) {
char *prefix1 = NULL, *prefix2=NULL;
tor_asprintf(&prefix1, "%s=", param_name);
tor_asprintf(&prefix2, " %s=", param_name);
if (strcmpstart(params, prefix1) == 0)
param_str = params;
else
param_str = strstr(params, prefix2);
tor_free(prefix1);
tor_free(prefix2);
}
if (param_str) {
int ok=0;
char *eq = strchr(param_str, '=');
if (eq) {
value = tor_parse_long(eq+1, 10, 1, INT32_MAX, &ok, NULL);
if (!ok) {
log_warn(LD_DIR, "Bad element '%s' in %s",
escaped(param_str), param_name);
value = default_value;
}
} else {
log_warn(LD_DIR, "Bad element '%s' in %s",
escaped(param_str), param_name);
value = default_value;
}
}
return value;
}
/** Given a list of networkstatus_t for each vote, return a newly allocated
* string containing the "package" lines for the vote. */
STATIC char *
......
......@@ -53,7 +53,7 @@
#define MIN_SUPPORTED_CONSENSUS_METHOD 28
/** The highest consensus method that we currently support. */
#define MAX_SUPPORTED_CONSENSUS_METHOD 30
#define MAX_SUPPORTED_CONSENSUS_METHOD 31
/**
* Lowest consensus method where microdescriptor lines are put in canonical
......@@ -65,6 +65,11 @@
* See #7869 */
#define MIN_METHOD_FOR_UNPADDED_NTOR_KEY 30
/** Lowest consensus method for which we use the correct algorithm for
* extracting the bwweightscale= and maxunmeasuredbw= parameters. See #19011.
*/
#define MIN_METHOD_FOR_CORRECT_BWWEIGHTSCALE 31
/** Default bandwidth to clip unmeasured bandwidths to using method >=
* MIN_METHOD_TO_CLIP_UNMEASURED_BW. (This is not a consensus method; do not
* get confused with the above macros.) */
......@@ -256,6 +261,9 @@ STATIC
char *networkstatus_get_detached_signatures(smartlist_t *consensuses);
STATIC microdesc_t *dirvote_create_microdescriptor(const routerinfo_t *ri,
int consensus_method);
STATIC int64_t extract_param_buggy(const char *params,
const char *param_name,
int64_t default_value);
/** The recommended relay protocols for this authority's votes.
* Recommending a new protocol causes old tor versions to log a warning.
......
......@@ -656,6 +656,30 @@ done:
ROUTER_FREE(pppp);
}
static void
test_dirvote_parse_param_buggy(void *arg)
{
(void)arg;
/* Tests for behavior with bug emulation to migrate away from bug 19011. */
tt_i64_op(extract_param_buggy("blah blah", "bwweightscale", 10000),
OP_EQ, 10000);
tt_i64_op(extract_param_buggy("bwweightscale=7", "bwweightscale", 10000),
OP_EQ, 7);
tt_i64_op(extract_param_buggy("bwweightscale=7 foo=9",
"bwweightscale", 10000),
OP_EQ, 10000);
tt_i64_op(extract_param_buggy("foo=7 bwweightscale=777 bar=9",
"bwweightscale", 10000),
OP_EQ, 10000);
tt_i64_op(extract_param_buggy("foo=7 bwweightscale=1234",
"bwweightscale", 10000),
OP_EQ, 1234);
done:
;
}
#define NODE(name, flags) \
{ \
#name, test_dirvote_##name, (flags), NULL, NULL \
......@@ -668,4 +692,5 @@ struct testcase_t dirvote_tests[] = {
NODE(get_sybil_by_ip_version_ipv4, TT_FORK),
NODE(get_sybil_by_ip_version_ipv6, TT_FORK),
NODE(get_all_possible_sybil, TT_FORK),
NODE(parse_param_buggy, 0),
END_OF_TESTCASES};
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