2018-09-20 14:09:35 +02:00
|
|
|
/* Copyright (c) 2001-2004, Roger Dingledine.
|
|
|
|
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
|
|
|
|
* Copyright (c) 2007-2018, The Tor Project, Inc. */
|
|
|
|
/* See LICENSE for licensing information */
|
|
|
|
|
|
|
|
/**
|
|
|
|
* \file bwauth.c
|
|
|
|
* \brief Code to read and apply guard fraction data.
|
|
|
|
**/
|
|
|
|
|
|
|
|
#define GUARDFRACTION_PRIVATE
|
|
|
|
#include "core/or/or.h"
|
|
|
|
#include "feature/dirauth/guardfraction.h"
|
|
|
|
#include "feature/nodelist/networkstatus.h"
|
2018-10-01 17:44:59 +02:00
|
|
|
#include "feature/dirparse/ns_parse.h"
|
2018-09-20 14:09:35 +02:00
|
|
|
|
|
|
|
#include "feature/nodelist/vote_routerstatus_st.h"
|
|
|
|
|
|
|
|
#include "lib/encoding/confline.h"
|
|
|
|
|
|
|
|
/** The guardfraction of the guard with identity fingerprint <b>guard_id</b>
|
|
|
|
* is <b>guardfraction_percentage</b>. See if we have a vote routerstatus for
|
|
|
|
* this guard in <b>vote_routerstatuses</b>, and if we do, register the
|
|
|
|
* information to it.
|
|
|
|
*
|
|
|
|
* Return 1 if we applied the information and 0 if we couldn't find a
|
|
|
|
* matching guard.
|
|
|
|
*
|
|
|
|
* Requires that <b>vote_routerstatuses</b> be sorted.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
guardfraction_line_apply(const char *guard_id,
|
|
|
|
uint32_t guardfraction_percentage,
|
|
|
|
smartlist_t *vote_routerstatuses)
|
|
|
|
{
|
|
|
|
vote_routerstatus_t *vrs = NULL;
|
|
|
|
|
|
|
|
tor_assert(vote_routerstatuses);
|
|
|
|
|
|
|
|
vrs = smartlist_bsearch(vote_routerstatuses, guard_id,
|
|
|
|
compare_digest_to_vote_routerstatus_entry);
|
|
|
|
|
|
|
|
if (!vrs) {
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
vrs->status.has_guardfraction = 1;
|
|
|
|
vrs->status.guardfraction_percentage = guardfraction_percentage;
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given a guard line from a guardfraction file, parse it and register
|
|
|
|
* its information to <b>vote_routerstatuses</b>.
|
|
|
|
*
|
|
|
|
* Return:
|
|
|
|
* * 1 if the line was proper and its information got registered.
|
|
|
|
* * 0 if the line was proper but no currently active guard was found
|
|
|
|
* to register the guardfraction information to.
|
|
|
|
* * -1 if the line could not be parsed and set <b>err_msg</b> to a
|
|
|
|
newly allocated string containing the error message.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
guardfraction_file_parse_guard_line(const char *guard_line,
|
|
|
|
smartlist_t *vote_routerstatuses,
|
|
|
|
char **err_msg)
|
|
|
|
{
|
|
|
|
char guard_id[DIGEST_LEN];
|
|
|
|
uint32_t guardfraction;
|
|
|
|
char *inputs_tmp = NULL;
|
|
|
|
int num_ok = 1;
|
|
|
|
|
|
|
|
smartlist_t *sl = smartlist_new();
|
|
|
|
int retval = -1;
|
|
|
|
|
|
|
|
tor_assert(err_msg);
|
|
|
|
|
|
|
|
/* guard_line should contain something like this:
|
|
|
|
<hex digest> <guardfraction> <appearances> */
|
|
|
|
smartlist_split_string(sl, guard_line, " ",
|
|
|
|
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
|
|
|
|
if (smartlist_len(sl) < 3) {
|
|
|
|
tor_asprintf(err_msg, "bad line '%s'", guard_line);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
inputs_tmp = smartlist_get(sl, 0);
|
|
|
|
if (strlen(inputs_tmp) != HEX_DIGEST_LEN ||
|
|
|
|
base16_decode(guard_id, DIGEST_LEN,
|
|
|
|
inputs_tmp, HEX_DIGEST_LEN) != DIGEST_LEN) {
|
|
|
|
tor_asprintf(err_msg, "bad digest '%s'", inputs_tmp);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
inputs_tmp = smartlist_get(sl, 1);
|
|
|
|
/* Guardfraction is an integer in [0, 100]. */
|
|
|
|
guardfraction =
|
|
|
|
(uint32_t) tor_parse_long(inputs_tmp, 10, 0, 100, &num_ok, NULL);
|
|
|
|
if (!num_ok) {
|
|
|
|
tor_asprintf(err_msg, "wrong percentage '%s'", inputs_tmp);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If routerstatuses were provided, apply this info to actual routers. */
|
|
|
|
if (vote_routerstatuses) {
|
|
|
|
retval = guardfraction_line_apply(guard_id, guardfraction,
|
|
|
|
vote_routerstatuses);
|
|
|
|
} else {
|
|
|
|
retval = 0; /* If we got this far, line was correctly formatted. */
|
|
|
|
}
|
|
|
|
|
|
|
|
done:
|
|
|
|
|
|
|
|
SMARTLIST_FOREACH(sl, char *, cp, tor_free(cp));
|
|
|
|
smartlist_free(sl);
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/** Given an inputs line from a guardfraction file, parse it and
|
|
|
|
* register its information to <b>total_consensuses</b> and
|
|
|
|
* <b>total_days</b>.
|
|
|
|
*
|
|
|
|
* Return 0 if it parsed well. Return -1 if there was an error, and
|
|
|
|
* set <b>err_msg</b> to a newly allocated string containing the
|
|
|
|
* error message.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
guardfraction_file_parse_inputs_line(const char *inputs_line,
|
|
|
|
int *total_consensuses,
|
|
|
|
int *total_days,
|
|
|
|
char **err_msg)
|
|
|
|
{
|
|
|
|
int retval = -1;
|
|
|
|
char *inputs_tmp = NULL;
|
|
|
|
int num_ok = 1;
|
|
|
|
smartlist_t *sl = smartlist_new();
|
|
|
|
|
|
|
|
tor_assert(err_msg);
|
|
|
|
|
|
|
|
/* Second line is inputs information:
|
|
|
|
* n-inputs <total_consensuses> <total_days>. */
|
|
|
|
smartlist_split_string(sl, inputs_line, " ",
|
|
|
|
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
|
|
|
|
if (smartlist_len(sl) < 2) {
|
|
|
|
tor_asprintf(err_msg, "incomplete line '%s'", inputs_line);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
inputs_tmp = smartlist_get(sl, 0);
|
|
|
|
*total_consensuses =
|
|
|
|
(int) tor_parse_long(inputs_tmp, 10, 0, INT_MAX, &num_ok, NULL);
|
|
|
|
if (!num_ok) {
|
|
|
|
tor_asprintf(err_msg, "unparseable consensus '%s'", inputs_tmp);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
inputs_tmp = smartlist_get(sl, 1);
|
|
|
|
*total_days =
|
|
|
|
(int) tor_parse_long(inputs_tmp, 10, 0, INT_MAX, &num_ok, NULL);
|
|
|
|
if (!num_ok) {
|
|
|
|
tor_asprintf(err_msg, "unparseable days '%s'", inputs_tmp);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
retval = 0;
|
|
|
|
|
|
|
|
done:
|
|
|
|
SMARTLIST_FOREACH(sl, char *, cp, tor_free(cp));
|
|
|
|
smartlist_free(sl);
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Maximum age of a guardfraction file that we are willing to accept. */
|
|
|
|
#define MAX_GUARDFRACTION_FILE_AGE (7*24*60*60) /* approx a week */
|
|
|
|
|
|
|
|
/** Static strings of guardfraction files. */
|
|
|
|
#define GUARDFRACTION_DATE_STR "written-at"
|
|
|
|
#define GUARDFRACTION_INPUTS "n-inputs"
|
|
|
|
#define GUARDFRACTION_GUARD "guard-seen"
|
|
|
|
#define GUARDFRACTION_VERSION "guardfraction-file-version"
|
|
|
|
|
|
|
|
/** Given a guardfraction file in a string, parse it and register the
|
|
|
|
* guardfraction information to the provided vote routerstatuses.
|
|
|
|
*
|
|
|
|
* This is the rough format of the guardfraction file:
|
|
|
|
*
|
|
|
|
* guardfraction-file-version 1
|
|
|
|
* written-at <date and time>
|
|
|
|
* n-inputs <number of consesuses parsed> <number of days considered>
|
|
|
|
*
|
|
|
|
* guard-seen <fpr 1> <guardfraction percentage> <consensus appearances>
|
|
|
|
* guard-seen <fpr 2> <guardfraction percentage> <consensus appearances>
|
|
|
|
* guard-seen <fpr 3> <guardfraction percentage> <consensus appearances>
|
|
|
|
* guard-seen <fpr 4> <guardfraction percentage> <consensus appearances>
|
|
|
|
* guard-seen <fpr 5> <guardfraction percentage> <consensus appearances>
|
|
|
|
* ...
|
|
|
|
*
|
|
|
|
* Return -1 if the parsing failed and 0 if it went smoothly. Parsing
|
|
|
|
* should tolerate errors in all lines but the written-at header.
|
|
|
|
*/
|
|
|
|
STATIC int
|
|
|
|
dirserv_read_guardfraction_file_from_str(const char *guardfraction_file_str,
|
|
|
|
smartlist_t *vote_routerstatuses)
|
|
|
|
{
|
|
|
|
config_line_t *front=NULL, *line;
|
|
|
|
int ret_tmp;
|
|
|
|
int retval = -1;
|
|
|
|
int current_line_n = 0; /* line counter for better log messages */
|
|
|
|
|
|
|
|
/* Guardfraction info to be parsed */
|
|
|
|
int total_consensuses = 0;
|
|
|
|
int total_days = 0;
|
|
|
|
|
|
|
|
/* Stats */
|
|
|
|
int guards_read_n = 0;
|
|
|
|
int guards_applied_n = 0;
|
|
|
|
|
|
|
|
/* Parse file and split it in lines */
|
|
|
|
ret_tmp = config_get_lines(guardfraction_file_str, &front, 0);
|
|
|
|
if (ret_tmp < 0) {
|
|
|
|
log_warn(LD_CONFIG, "Error reading from guardfraction file");
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Sort routerstatuses (needed later when applying guardfraction info) */
|
|
|
|
if (vote_routerstatuses)
|
|
|
|
smartlist_sort(vote_routerstatuses, compare_vote_routerstatus_entries);
|
|
|
|
|
|
|
|
for (line = front; line; line=line->next) {
|
|
|
|
current_line_n++;
|
|
|
|
|
|
|
|
if (!strcmp(line->key, GUARDFRACTION_VERSION)) {
|
|
|
|
int num_ok = 1;
|
|
|
|
unsigned int version;
|
|
|
|
|
|
|
|
version =
|
|
|
|
(unsigned int) tor_parse_long(line->value,
|
|
|
|
10, 0, INT_MAX, &num_ok, NULL);
|
|
|
|
|
|
|
|
if (!num_ok || version != 1) {
|
|
|
|
log_warn(LD_GENERAL, "Got unknown guardfraction version %d.", version);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
} else if (!strcmp(line->key, GUARDFRACTION_DATE_STR)) {
|
|
|
|
time_t file_written_at;
|
|
|
|
time_t now = time(NULL);
|
|
|
|
|
|
|
|
/* First line is 'written-at <date>' */
|
|
|
|
if (parse_iso_time(line->value, &file_written_at) < 0) {
|
|
|
|
log_warn(LD_CONFIG, "Guardfraction:%d: Bad date '%s'. Ignoring",
|
|
|
|
current_line_n, line->value);
|
|
|
|
goto done; /* don't tolerate failure here. */
|
|
|
|
}
|
|
|
|
if (file_written_at < now - MAX_GUARDFRACTION_FILE_AGE) {
|
|
|
|
log_warn(LD_CONFIG, "Guardfraction:%d: was written very long ago '%s'",
|
|
|
|
current_line_n, line->value);
|
|
|
|
goto done; /* don't tolerate failure here. */
|
|
|
|
}
|
|
|
|
} else if (!strcmp(line->key, GUARDFRACTION_INPUTS)) {
|
|
|
|
char *err_msg = NULL;
|
|
|
|
|
|
|
|
if (guardfraction_file_parse_inputs_line(line->value,
|
|
|
|
&total_consensuses,
|
|
|
|
&total_days,
|
|
|
|
&err_msg) < 0) {
|
|
|
|
log_warn(LD_CONFIG, "Guardfraction:%d: %s",
|
|
|
|
current_line_n, err_msg);
|
|
|
|
tor_free(err_msg);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
} else if (!strcmp(line->key, GUARDFRACTION_GUARD)) {
|
|
|
|
char *err_msg = NULL;
|
|
|
|
|
|
|
|
ret_tmp = guardfraction_file_parse_guard_line(line->value,
|
|
|
|
vote_routerstatuses,
|
|
|
|
&err_msg);
|
|
|
|
if (ret_tmp < 0) { /* failed while parsing the guard line */
|
|
|
|
log_warn(LD_CONFIG, "Guardfraction:%d: %s",
|
|
|
|
current_line_n, err_msg);
|
|
|
|
tor_free(err_msg);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Successfully parsed guard line. Check if it was applied properly. */
|
|
|
|
guards_read_n++;
|
|
|
|
if (ret_tmp > 0) {
|
|
|
|
guards_applied_n++;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
log_warn(LD_CONFIG, "Unknown guardfraction line %d (%s %s)",
|
|
|
|
current_line_n, line->key, line->value);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
retval = 0;
|
|
|
|
|
|
|
|
log_info(LD_CONFIG,
|
|
|
|
"Successfully parsed guardfraction file with %d consensuses over "
|
|
|
|
"%d days. Parsed %d nodes and applied %d of them%s.",
|
|
|
|
total_consensuses, total_days, guards_read_n, guards_applied_n,
|
|
|
|
vote_routerstatuses ? "" : " (no routerstatus provided)" );
|
|
|
|
|
|
|
|
done:
|
|
|
|
config_free_lines(front);
|
|
|
|
|
|
|
|
if (retval < 0) {
|
|
|
|
return retval;
|
|
|
|
} else {
|
|
|
|
return guards_read_n;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/** Read a guardfraction file at <b>fname</b> and load all its
|
|
|
|
* information to <b>vote_routerstatuses</b>. */
|
|
|
|
int
|
|
|
|
dirserv_read_guardfraction_file(const char *fname,
|
|
|
|
smartlist_t *vote_routerstatuses)
|
|
|
|
{
|
|
|
|
char *guardfraction_file_str;
|
|
|
|
|
|
|
|
/* Read file to a string */
|
|
|
|
guardfraction_file_str = read_file_to_str(fname, RFTS_IGNORE_MISSING, NULL);
|
|
|
|
if (!guardfraction_file_str) {
|
|
|
|
log_warn(LD_FS, "Cannot open guardfraction file '%s'. Failing.", fname);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return dirserv_read_guardfraction_file_from_str(guardfraction_file_str,
|
|
|
|
vote_routerstatuses);
|
|
|
|
}
|