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Extract field-parsing code for microdesc_parse.c

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The code here parses the fields from the microdescriptor, including
possible annotations, and stores them into a microdesc_t object.

This commit is almost pure code movement; I recommend using
--color-moved to review it.
This commit is contained in:
Nick Mathewson 2019-09-09 15:41:24 -04:00
parent b1552e8814
commit ec368409fa
1 changed files with 83 additions and 60 deletions
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143
src/feature/dirparse/microdesc_parse.c
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@ -162,62 +162,27 @@ microdesc_extract_body(microdesc_t *md,
return no_onion_key ? -1 : 0;
}
/** Parse as many microdescriptors as are found from the string starting at
* <b>s</b> and ending at <b>eos</b>. If allow_annotations is set, read any
* annotations we recognize and ignore ones we don't.
/**
* Parse a microdescriptor which begins at <b>s</b> and ends at
* <b>start_of_next_microdesc. Store its fields into <b>md</b>. Use
* <b>where</b> for generating log information. If <b>allow_annotations</b>
* is true, then one or more annotations may precede the microdescriptor body
* proper. Use <b>area</b> for memory management, clearing it when done.
*
* If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
* descriptor in the body field of each microdesc_t.
*
* Return all newly parsed microdescriptors in a newly allocated
* smartlist_t. If <b>invalid_disgests_out</b> is provided, add a SHA256
* microdesc digest to it for every microdesc that we found to be badly
* formed. (This may cause duplicates) */
smartlist_t *
microdescs_parse_from_string(const char *s, const char *eos,
int allow_annotations,
saved_location_t where,
smartlist_t *invalid_digests_out)
* On success, return 0; otherwise return -1.
**/
static int
microdesc_parse_fields(microdesc_t *md,
memarea_t *area,
const char *s, const char *start_of_next_microdesc,
int allow_annotations,
saved_location_t where)
{
smartlist_t *tokens;
smartlist_t *result;
microdesc_t *md = NULL;
memarea_t *area;
const char *start = s;
const char *start_of_next_microdesc;
smartlist_t *tokens = smartlist_new();
int rv = -1;
int flags = allow_annotations ? TS_ANNOTATIONS_OK : 0;
directory_token_t *tok;
if (!eos)
eos = s + strlen(s);
s = eat_whitespace_eos(s, eos);
area = memarea_new();
result = smartlist_new();
tokens = smartlist_new();
while (s < eos) {
int okay = 0;
start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
if (!start_of_next_microdesc)
start_of_next_microdesc = eos;
md = tor_malloc_zero(sizeof(microdesc_t));
uint8_t md_digest[DIGEST256_LEN];
{
int body_not_found = microdesc_extract_body(md, start, s,
start_of_next_microdesc,
where) < 0;
memcpy(md_digest, md->digest, DIGEST256_LEN);
if (body_not_found) {
log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Malformed or truncated descriptor");
goto next;
}
}
if (tokenize_string(area, s, start_of_next_microdesc, tokens,
microdesc_token_table, flags)) {
log_warn(LD_DIR, "Unparseable microdescriptor found in %s",
@ -301,10 +266,74 @@ microdescs_parse_from_string(const char *s, const char *eos,
md->policy_is_reject_star = 1;
}
smartlist_add(result, md);
okay = 1;
rv = 0;
next: // todo: rename this label.
SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
memarea_clear(area);
smartlist_free(tokens);
return rv;
}
/** Parse as many microdescriptors as are found from the string starting at
* <b>s</b> and ending at <b>eos</b>. If allow_annotations is set, read any
* annotations we recognize and ignore ones we don't.
*
* If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
* descriptor in the body field of each microdesc_t.
*
* Return all newly parsed microdescriptors in a newly allocated
* smartlist_t. If <b>invalid_disgests_out</b> is provided, add a SHA256
* microdesc digest to it for every microdesc that we found to be badly
* formed. (This may cause duplicates) */
smartlist_t *
microdescs_parse_from_string(const char *s, const char *eos,
int allow_annotations,
saved_location_t where,
smartlist_t *invalid_digests_out)
{
smartlist_t *result;
microdesc_t *md = NULL;
memarea_t *area;
const char *start = s;
const char *start_of_next_microdesc;
if (!eos)
eos = s + strlen(s);
s = eat_whitespace_eos(s, eos);
area = memarea_new();
result = smartlist_new();
while (s < eos) {
int okay = 0;
start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
if (!start_of_next_microdesc)
start_of_next_microdesc = eos;
md = tor_malloc_zero(sizeof(microdesc_t));
uint8_t md_digest[DIGEST256_LEN];
{
int body_not_found = microdesc_extract_body(md, start, s,
start_of_next_microdesc,
where) < 0;
memcpy(md_digest, md->digest, DIGEST256_LEN);
if (body_not_found) {
log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Malformed or truncated descriptor");
goto next;
}
}
if (microdesc_parse_fields(md, area, s, start_of_next_microdesc,
allow_annotations, where) == 0) {
smartlist_add(result, md);
md = NULL; // prevent free
okay = 1;
}
md = NULL;
next:
if (! okay && invalid_digests_out) {
smartlist_add(invalid_digests_out,
@ -312,16 +341,10 @@ microdescs_parse_from_string(const char *s, const char *eos,
}
microdesc_free(md);
md = NULL;
SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
memarea_clear(area);
smartlist_clear(tokens);
s = start_of_next_microdesc;
}
SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
memarea_drop_all(area);
smartlist_free(tokens);
return result;
}