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r12387@catbus: nickm | 2007-04-16 00:06:40 -0400

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Refactor router/directory parsing backend: use a separate token table for everything that we parse, and enforce the correct count of each item.


svn:r9965
This commit is contained in:
Nick Mathewson 2007-04-16 04:18:21 +00:00
parent 108f1c255f
commit cf02ab6d39
2 changed files with 147 additions and 93 deletions
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2
ChangeLog
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@ -53,6 +53,8 @@ Changes in version 0.2.0.1-alpha - 2007-??-??
- Don't save non-general-purpose router descriptors to the disk cache,
because we have no way of remembering what their purpose was when
we restart.
- Correctly enforce that elements of directory objects do not appear
more often than they are allowed to appear.
o Minor bugfixes (controller), reported by daejees:
- Make 'getinfo fingerprint' return a 551 error if we're not a

236
src/or/routerparse.c
View File

@ -22,7 +22,7 @@ const char routerparse_c_id[] =
* not-a-token.
*/
typedef enum {
K_ACCEPT,
K_ACCEPT = 0,
K_DIRECTORY_SIGNATURE,
K_RECOMMENDED_SOFTWARE,
K_REJECT,
@ -102,63 +102,105 @@ typedef enum {
OBJ_OK, /**< Object is optional. */
} obj_syntax;
/** Rules for where a keyword can appear. */
typedef enum {
DIR = 1, /**< Appears only in directory. */
RTR = 2, /**< Appears only in router descriptor or runningrouters. */
NETSTATUS = 4, /**< v2 or later ("versioned") network status. */
ANYSIGNED = 7, /**< Any "full" document (that is, not a router status.) */
RTRSTATUS = 8, /**< Router-status portion of a versioned network status. */
EXTRAINFO = 16, /**< DOCDOC */
ANY = 31, /**< Appears in any document type. */
} where_syntax;
/** DOCDOC */
typedef struct token_rule_t {
const char *t; directory_keyword v; arg_syntax s; obj_syntax os;
int min_cnt; int max_cnt;
} token_rule_t;
/** Table mapping keywords to token value and to argument rules. */
static struct {
const char *t; directory_keyword v; arg_syntax s; obj_syntax os; int ws;
} token_table[] = {
{ "accept", K_ACCEPT, ARGS, NO_OBJ, RTR },
{ "directory-signature", K_DIRECTORY_SIGNATURE, ARGS, NEED_OBJ,
DIR|NETSTATUS},
{ "r", K_R, ARGS, NO_OBJ, RTRSTATUS },
{ "s", K_S, ARGS, NO_OBJ, RTRSTATUS },
{ "v", K_V, CONCAT_ARGS, NO_OBJ, RTRSTATUS },
{ "reject", K_REJECT, ARGS, NO_OBJ, RTR },
{ "router", K_ROUTER, ARGS, NO_OBJ, RTR },
{ "recommended-software",K_RECOMMENDED_SOFTWARE,ARGS, NO_OBJ, DIR },
{ "signed-directory", K_SIGNED_DIRECTORY, NO_ARGS, NO_OBJ, DIR },
{ "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY,RTR },
{ "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY,RTR },
{ "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ,RTR|EXTRAINFO },
{ "running-routers", K_RUNNING_ROUTERS, ARGS, NO_OBJ, DIR },
{ "router-status", K_ROUTER_STATUS, ARGS, NO_OBJ, DIR },
{ "bandwidth", K_BANDWIDTH, ARGS, NO_OBJ, RTR },
{ "platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ, RTR },
{ "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ, ANYSIGNED|EXTRAINFO },
{ "opt", K_OPT, CONCAT_ARGS, OBJ_OK, ANY },
{ "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ, ANYSIGNED },
{ "network-status", K_NETWORK_STATUS, NO_ARGS, NO_OBJ, DIR },
{ "uptime", K_UPTIME, ARGS, NO_OBJ, RTR },
{ "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, OBJ_OK,
DIR|NETSTATUS},
{ "family", K_FAMILY, ARGS, NO_OBJ, RTR },
{ "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ, ANYSIGNED },
{ "hibernating", K_HIBERNATING, ARGS, NO_OBJ, RTR },
{ "read-history", K_READ_HISTORY, ARGS, NO_OBJ, RTR|EXTRAINFO },
{ "write-history", K_WRITE_HISTORY, ARGS, NO_OBJ, RTR|EXTRAINFO },
{ "network-status-version", K_NETWORK_STATUS_VERSION,
ARGS, NO_OBJ, NETSTATUS },
{ "dir-source", K_DIR_SOURCE, ARGS, NO_OBJ, NETSTATUS },
{ "dir-options", K_DIR_OPTIONS, ARGS, NO_OBJ, NETSTATUS },
{ "client-versions", K_CLIENT_VERSIONS, ARGS, NO_OBJ, NETSTATUS },
{ "server-versions", K_SERVER_VERSIONS, ARGS, NO_OBJ, NETSTATUS },
{ "eventdns", K_EVENTDNS, ARGS, NO_OBJ, RTR },
{ "extra-info", K_EXTRA_INFO, ARGS, NO_OBJ, EXTRAINFO },
{ "extra-info-digest", K_EXTRA_INFO_DIGEST, ARGS, NO_OBJ, RTR },
{ "caches-extra-info", K_CACHES_EXTRA_INFO, NO_ARGS, NO_OBJ, RTR },
{ NULL, _NIL, NO_ARGS, NO_OBJ, ANY }
/** DOCDOC */
#define END_OF_TABLE { NULL, _NIL, NO_ARGS, NO_OBJ, 0, INT_MAX }
#define T(s,t,a,o) { s, t, a, o, 0, INT_MAX }
#define T0N(s,t,a,o) { s, t, a, o, 0, INT_MAX }
#define T1(s,t,a,o) { s, t, a, o, 1, 1 }
#define T01(s,t,a,o) { s, t, a, o, 0, 1 }
/** DOCDOC */
static token_rule_t routerdesc_token_table[] = {
T0N("accept", K_ACCEPT, ARGS, NO_OBJ ),
T0N("reject", K_REJECT, ARGS, NO_OBJ ),
T1( "router", K_ROUTER, ARGS, NO_OBJ ),
T1( "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY ),
T1( "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY ),
T1( "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ ),
T1( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
T01("contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
T01("uptime", K_UPTIME, ARGS, NO_OBJ ),
T01("family", K_FAMILY, ARGS, NO_OBJ ),
T01("fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
T01("hibernating", K_HIBERNATING, ARGS, NO_OBJ ),
T01("read-history", K_READ_HISTORY, ARGS, NO_OBJ ),
T01("write-history", K_WRITE_HISTORY, ARGS, NO_OBJ ),
T01("eventdns", K_EVENTDNS, ARGS, NO_OBJ ),
T01("extra-info-digest", K_EXTRA_INFO_DIGEST, ARGS, NO_OBJ ),
T01("caches-extra-info", K_CACHES_EXTRA_INFO, NO_ARGS, NO_OBJ ),
T1("bandwidth", K_BANDWIDTH, ARGS, NO_OBJ ),
T01("platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ ),
END_OF_TABLE
};
static token_rule_t extrainfo_token_table[] = {
T1( "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ ),
T1( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
T01("read-history", K_READ_HISTORY, ARGS, NO_OBJ ),
T01("write-history", K_WRITE_HISTORY, ARGS, NO_OBJ ),
T1( "extra-info", K_EXTRA_INFO, ARGS, NO_OBJ ),
END_OF_TABLE
};
static token_rule_t rtrstatus_token_table[] = {
T1( "r", K_R, ARGS, NO_OBJ ),
T1( "s", K_S, ARGS, NO_OBJ ),
T01("v", K_V, CONCAT_ARGS, NO_OBJ ),
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
END_OF_TABLE
};
static token_rule_t netstatus_token_table[] = {
T1( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
T1( "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
T1( "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, OBJ_OK ),
T1( "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
T1( "network-status-version", K_NETWORK_STATUS_VERSION,
ARGS, NO_OBJ ),
T1( "dir-source", K_DIR_SOURCE, ARGS, NO_OBJ ),
T01("dir-options", K_DIR_OPTIONS, ARGS, NO_OBJ ),
T01("client-versions", K_CLIENT_VERSIONS, ARGS, NO_OBJ ),
T01("server-versions", K_SERVER_VERSIONS, ARGS, NO_OBJ ),
END_OF_TABLE
};
static token_rule_t dir_footer_token_table[] = {
T1( "directory-signature", K_DIRECTORY_SIGNATURE, ARGS, NEED_OBJ ),
END_OF_TABLE
};
static token_rule_t dir_token_table[] = {
/* don't enforce counts; this is obsolete. */
T( "network-status", K_NETWORK_STATUS, NO_ARGS, NO_OBJ ),
T( "directory-signature", K_DIRECTORY_SIGNATURE, ARGS, NEED_OBJ ),
T( "recommended-software",K_RECOMMENDED_SOFTWARE,ARGS, NO_OBJ ),
T( "signed-directory", K_SIGNED_DIRECTORY, NO_ARGS, NO_OBJ ),
T( "running-routers", K_RUNNING_ROUTERS, ARGS, NO_OBJ ),
T( "router-status", K_ROUTER_STATUS, ARGS, NO_OBJ ),
T( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
T( "opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
T( "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
T( "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, OBJ_OK ),
T( "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
END_OF_TABLE
};
#undef T
/* static function prototypes */
static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok);
static addr_policy_t *router_parse_addr_policy(directory_token_t *tok);
@ -171,8 +213,10 @@ static smartlist_t *find_all_exitpolicy(smartlist_t *s);
static directory_token_t *find_first_by_keyword(smartlist_t *s,
directory_keyword keyword);
static int tokenize_string(const char *start, const char *end,
smartlist_t *out, where_syntax where);
static directory_token_t *get_next_token(const char **s, where_syntax where);
smartlist_t *out,
struct token_rule_t *table);
static directory_token_t *get_next_token(const char **s,
struct token_rule_t *table);
static int check_directory_signature(const char *digest,
directory_token_t *tok,
crypto_pk_env_t *pkey,
@ -402,7 +446,7 @@ router_parse_directory(const char *str)
}
++cp;
tokens = smartlist_create();
if (tokenize_string(cp,strchr(cp,'\0'),tokens,DIR)) {
if (tokenize_string(cp,strchr(cp,'\0'),tokens,dir_token_table)) {
log_warn(LD_DIR, "Error tokenizing directory signature"); goto err;
}
if (smartlist_len(tokens) != 1) {
@ -431,7 +475,7 @@ router_parse_directory(const char *str)
}
tokens = smartlist_create();
if (tokenize_string(str,end,tokens,DIR)) {
if (tokenize_string(str,end,tokens,dir_token_table)) {
log_warn(LD_DIR, "Error tokenizing directory"); goto err;
}
@ -481,7 +525,7 @@ router_parse_runningrouters(const char *str)
goto err;
}
tokens = smartlist_create();
if (tokenize_string(str,str+strlen(str),tokens,DIR)) {
if (tokenize_string(str,str+strlen(str),tokens,dir_token_table)) {
log_warn(LD_DIR, "Error tokenizing running-routers"); goto err;
}
tok = smartlist_get(tokens,0);
@ -540,7 +584,7 @@ find_dir_signing_key(const char *str)
return NULL;
++cp; /* Now cp points to the start of the token. */
tok = get_next_token(&cp, DIR);
tok = get_next_token(&cp, dir_token_table);
if (!tok) {
log_warn(LD_DIR, "Unparseable dir-signing-key token");
return NULL;
@ -772,7 +816,7 @@ router_parse_entry_from_string(const char *s, const char *end,
return NULL;
}
tokens = smartlist_create();
if (tokenize_string(s,end,tokens,RTR)) {
if (tokenize_string(s,end,tokens,routerdesc_token_table)) {
log_warn(LD_DIR, "Error tokeninzing router descriptor.");
goto err;
}
@ -1038,7 +1082,7 @@ extrainfo_parse_entry_from_string(const char *s, const char *end,
return NULL;
}
tokens = smartlist_create();
if (tokenize_string(s,end,tokens,EXTRAINFO)) {
if (tokenize_string(s,end,tokens,extrainfo_token_table)) {
log_warn(LD_DIR, "Error tokeninzing router descriptor.");
goto err;
}
@ -1162,7 +1206,7 @@ routerstatus_parse_entry_from_string(const char **s, smartlist_t *tokens)
eos = find_start_of_next_routerstatus(*s);
if (tokenize_string(*s, eos, tokens, RTRSTATUS)) {
if (tokenize_string(*s, eos, tokens, rtrstatus_token_table)) {
log_warn(LD_DIR, "Error tokenizing router status");
goto err;
}
@ -1297,6 +1341,7 @@ networkstatus_parse_from_string(const char *s)
{
const char *eos;
smartlist_t *tokens = smartlist_create();
smartlist_t *footer_tokens = smartlist_create();
networkstatus_t *ns = NULL;
char ns_digest[DIGEST_LEN];
char tmp_digest[DIGEST_LEN];
@ -1310,7 +1355,7 @@ networkstatus_parse_from_string(const char *s)
}
eos = find_start_of_next_routerstatus(s);
if (tokenize_string(s, eos, tokens, NETSTATUS)) {
if (tokenize_string(s, eos, tokens, netstatus_token_table)) {
log_warn(LD_DIR, "Error tokenizing network-status header.");
goto err;
}
@ -1433,15 +1478,15 @@ networkstatus_parse_from_string(const char *s)
smartlist_uniq(ns->entries, _compare_routerstatus_entries,
_free_duplicate_routerstatus_entry);
if (tokenize_string(s, NULL, tokens, NETSTATUS)) {
if (tokenize_string(s, NULL, footer_tokens, dir_footer_token_table)) {
log_warn(LD_DIR, "Error tokenizing network-status footer.");
goto err;
}
if (smartlist_len(tokens) < 1) {
if (smartlist_len(footer_tokens) < 1) {
log_warn(LD_DIR, "Too few items in network-status footer.");
goto err;
}
tok = smartlist_get(tokens, smartlist_len(tokens)-1);
tok = smartlist_get(footer_tokens, smartlist_len(footer_tokens)-1);
if (tok->tp != K_DIRECTORY_SIGNATURE) {
log_warn(LD_DIR,
"Expected network-status footer to end with a signature.");
@ -1460,6 +1505,8 @@ networkstatus_parse_from_string(const char *s)
done:
SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_free(t));
smartlist_free(tokens);
SMARTLIST_FOREACH(footer_tokens, directory_token_t *, t, token_free(t));
smartlist_free(footer_tokens);
return ns;
}
@ -1494,7 +1541,7 @@ router_parse_addr_policy_from_string(const char *s, int assume_action)
tor_free(tmp);
cp = tmp = new_str;
}
tok = get_next_token(&cp, RTR);
tok = get_next_token(&cp, routerdesc_token_table);
if (tok->tp == _ERR) {
log_warn(LD_DIR, "Error reading address policy: %s", tok->error);
goto err;
@ -1668,11 +1715,10 @@ token_free(directory_token_t *tok)
}
/** Helper function: read the next token from *s, advance *s to the end
* of the token, and return the parsed token. If 'where' is DIR
* or RTR, reject all tokens of the wrong type.
* of the token, and return the parsed token. DOCDOC table
*/
static directory_token_t *
get_next_token(const char **s, where_syntax where)
get_next_token(const char **s, struct token_rule_t *table)
{
const char *next, *obstart;
int i, done, allocated, is_opt;
@ -1710,23 +1756,12 @@ get_next_token(const char **s, where_syntax where)
RET_ERR("opt without keyword");
}
}
for (i = 0; token_table[i].t ; ++i) {
if (!strncmp(token_table[i].t, *s, next-*s)) {
for (i = 0; table[i].t ; ++i) {
if (!strncmp(table[i].t, *s, next-*s)) {
/* We've found the keyword. */
tok->tp = token_table[i].v;
a_syn = token_table[i].s;
o_syn = token_table[i].os;
if (!(token_table[i].ws & where)) {
if (where == DIR) {
RET_ERR("Found an out-of-place token in a directory section");
} else if (where == RTR) {
RET_ERR("Found an out-of-place token in a router descriptor");
} else if (where == NETSTATUS) {
RET_ERR("Found an out-of-place token in a network-status header");
} else {
RET_ERR("Found an out-of-place token in a router status body");
}
}
tok->tp = table[i].v;
a_syn = table[i].s;
o_syn = table[i].os;
if (a_syn == ARGS) {
/* This keyword takes multiple arguments. */
i = 0;
@ -1846,28 +1881,45 @@ get_next_token(const char **s, where_syntax where)
}
/** Read all tokens from a string between <b>start</b> and <b>end</b>, and add
* them to <b>out</b>. If <b>is_dir</b> is true, reject all non-directory
* tokens; else reject all non-routerdescriptor tokens.
* them to <b>out</b>. DOCDOC table.
*/
static int
tokenize_string(const char *start, const char *end, smartlist_t *out,
where_syntax where)
token_rule_t *table)
{
const char **s;
directory_token_t *tok = NULL;
int counts[_NIL];
int i;
s = &start;
if (!end)
end = start+strlen(start);
memset(counts, 0, sizeof(counts));
for (i = 0; i < _NIL; ++i)
counts[i] = 0;
while (*s < end && (!tok || tok->tp != _EOF)) {
tok = get_next_token(s, where);
tok = get_next_token(s, table);
if (tok->tp == _ERR) {
log_warn(LD_DIR, "parse error: %s", tok->error);
return -1;
}
++counts[tok->tp];
smartlist_add(out, tok);
*s = eat_whitespace(*s);
}
for (i = 0; table[i].t; ++i) {
if (counts[table[i].v] < table[i].min_cnt) {
log_warn(LD_DIR, "Parse error: missing %s element.", table[i].t);
tor_assert(0);
return -1;
}
if (counts[table[i].v] > table[i].max_cnt) {
log_warn(LD_DIR, "Parse error: too many %s elements.", table[i].t);
return -1;
}
}
return 0;
}