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More gracefully handle corrupt state files.

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Save a backup if we get odd circuitbuildtimes and other state info.

In the case of circuit build times, we no longer assert, and reset our state.
This commit is contained in:
Mike Perry
2010-07-06 12:08:13 -07:00
parent 7bbdf71a82
commit a9edb0b4f6
3 changed files with 69 additions and 31 deletions
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changes/cbt-bugfixes
+2
View File
@@ -29,5 +29,7 @@
parameter and via a LearnCircuitBuildTimeout config option. Also
automatically disable circuit build time calculation if we are either
a AuthoritativeDirectory, or if we fail to write our state file. Bug 1296.
- More gracefully handle corrupt state files, removing asserts in favor
of saving a backup and resetting state.
src/or/circuitbuild.c
+23 -4
View File
@@ -193,12 +193,11 @@ circuit_build_times_new_consensus_params(circuit_build_times_t *cbt,
int32_t num = networkstatus_get_param(ns, "cbtrecentcount",
CBT_DEFAULT_RECENT_CIRCUITS);
if (num != cbt->liveness.num_recent_circs) {
if (num > 0 && num != cbt->liveness.num_recent_circs) {
int8_t *recent_circs;
log_notice(LD_CIRC, "Changing recent timeout size from %d to %d",
cbt->liveness.num_recent_circs, num);
tor_assert(num > 0);
tor_assert(cbt->liveness.timeouts_after_firsthop);
/*
@@ -675,6 +674,10 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
"Corrupt state file? Build times count mismatch. "
"Read %d times, but file says %d", loaded_cnt,
state->TotalBuildTimes);
*msg = tor_strdup("Build times count mismatch.");
circuit_build_times_reset(cbt);
tor_free(loaded_times);
return -1;
}
circuit_build_times_shuffle_and_store_array(cbt, loaded_times, loaded_cnt);
@@ -688,8 +691,18 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
log_info(LD_CIRC,
"Loaded %d/%d values from %d lines in circuit time histogram",
tot_values, cbt->total_build_times, N);
tor_assert(cbt->total_build_times == tot_values);
tor_assert(cbt->total_build_times <= CBT_NCIRCUITS_TO_OBSERVE);
if (cbt->total_build_times != tot_values
|| cbt->total_build_times > CBT_NCIRCUITS_TO_OBSERVE) {
log_warn(LD_CIRC,
"Corrupt state file? Shuffled build times mismatch. "
"Read %d times, but file says %d", tot_values,
state->TotalBuildTimes);
*msg = tor_strdup("Build times count mismatch.");
circuit_build_times_reset(cbt);
tor_free(loaded_times);
return -1;
}
circuit_build_times_set_timeout(cbt);
@@ -742,6 +755,12 @@ circuit_build_times_update_alpha(circuit_build_times_t *cbt)
n++;
}
/*
* We are erring and asserting here because this can only happen
* in codepaths other than startup. The startup state parsing code
* performs this same check, and resets state if it hits it. If we
* hit it at runtime, something serious has gone wrong.
*/
if (n!=cbt->total_build_times) {
log_err(LD_CIRC, "Discrepancy in build times count: %d vs %d", n,
cbt->total_build_times);
src/or/config.c
+44 -27
View File
@@ -4837,25 +4837,63 @@ or_state_validate(or_state_t *old_state, or_state_t *state,
}
/** Replace the current persistent state with <b>new_state</b> */
static void
static int
or_state_set(or_state_t *new_state)
{
char *err = NULL;
int ret = 0;
tor_assert(new_state);
config_free(&state_format, global_state);
global_state = new_state;
if (entry_guards_parse_state(global_state, 1, &err)<0) {
log_warn(LD_GENERAL,"%s",err);
tor_free(err);
ret = -1;
}
if (rep_hist_load_state(global_state, &err)<0) {
log_warn(LD_GENERAL,"Unparseable bandwidth history state: %s",err);
tor_free(err);
ret = -1;
}
if (circuit_build_times_parse_state(&circ_times, global_state, &err) < 0) {
log_warn(LD_GENERAL,"%s",err);
tor_free(err);
ret = -1;
}
return ret;
}
/**
* Save a broken state file to a backup location.
*/
static void
or_state_save_broken(char *fname)
{
int i;
file_status_t status;
size_t len = strlen(fname)+16;
char *fname2 = tor_malloc(len);
for (i = 0; i < 100; ++i) {
tor_snprintf(fname2, len, "%s.%d", fname, i);
status = file_status(fname2);
if (status == FN_NOENT)
break;
}
if (i == 100) {
log_warn(LD_BUG, "Unable to parse state in \"%s\"; too many saved bad "
"state files to move aside. Discarding the old state file.",
fname);
unlink(fname);
} else {
log_warn(LD_BUG, "Unable to parse state in \"%s\". Moving it aside "
"to \"%s\". This could be a bug in Tor; please tell "
"the developers.", fname, fname2);
if (rename(fname, fname2) < 0) {
log_warn(LD_BUG, "Weirdly, I couldn't even move the state aside. The "
"OS gave an error of %s", strerror(errno));
}
}
tor_free(fname2);
}
/** Reload the persistent state from disk, generating a new state as needed.
@@ -4917,31 +4955,8 @@ or_state_load(void)
" This is a bug in Tor.");
goto done;
} else if (badstate && contents) {
int i;
file_status_t status;
size_t len = strlen(fname)+16;
char *fname2 = tor_malloc(len);
for (i = 0; i < 100; ++i) {
tor_snprintf(fname2, len, "%s.%d", fname, i);
status = file_status(fname2);
if (status == FN_NOENT)
break;
}
if (i == 100) {
log_warn(LD_BUG, "Unable to parse state in \"%s\"; too many saved bad "
"state files to move aside. Discarding the old state file.",
fname);
unlink(fname);
} else {
log_warn(LD_BUG, "Unable to parse state in \"%s\". Moving it aside "
"to \"%s\". This could be a bug in Tor; please tell "
"the developers.", fname, fname2);
if (rename(fname, fname2) < 0) {
log_warn(LD_BUG, "Weirdly, I couldn't even move the state aside. The "
"OS gave an error of %s", strerror(errno));
}
}
tor_free(fname2);
or_state_save_broken(fname);
tor_free(contents);
config_free(&state_format, new_state);
@@ -4953,7 +4968,9 @@ or_state_load(void)
} else {
log_info(LD_GENERAL, "Initialized state");
}
or_state_set(new_state);
if (or_state_set(new_state) == -1) {
or_state_save_broken(fname);
}
new_state = NULL;
if (!contents) {
global_state->next_write = 0;