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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, - Don't save non-general-purpose router descriptors to the disk cache,
because we have no way of remembering what their purpose was when because we have no way of remembering what their purpose was when
we restart. 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: o Minor bugfixes (controller), reported by daejees:
- Make 'getinfo fingerprint' return a 551 error if we're not a - Make 'getinfo fingerprint' return a 551 error if we're not a

238
src/or/routerparse.c
View File

@ -22,7 +22,7 @@ const char routerparse_c_id[] =
* not-a-token. * not-a-token.
*/ */
typedef enum { typedef enum {
K_ACCEPT, K_ACCEPT = 0,
K_DIRECTORY_SIGNATURE, K_DIRECTORY_SIGNATURE,
K_RECOMMENDED_SOFTWARE, K_RECOMMENDED_SOFTWARE,
K_REJECT, K_REJECT,
@ -77,7 +77,7 @@ typedef struct directory_token_t {
int n_args; /**< Number of elements in args */ int n_args; /**< Number of elements in args */
char **args; /**< Array of arguments from keyword line. */ char **args; /**< Array of arguments from keyword line. */
char *object_type; /**< -----BEGIN [object_type]-----*/ char *object_type; /**< -----BEGIN [object_type]-----*/
size_t object_size; /**< Bytes in object_body */ size_t object_size; /**< Bytes in object_body */
char *object_body; /**< Contents of object, base64-decoded. */ char *object_body; /**< Contents of object, base64-decoded. */
crypto_pk_env_t *key; /**< For public keys only. */ crypto_pk_env_t *key; /**< For public keys only. */
const char *error; /**< For _ERR tokens only. */ const char *error; /**< For _ERR tokens only. */
@ -102,63 +102,105 @@ typedef enum {
OBJ_OK, /**< Object is optional. */ OBJ_OK, /**< Object is optional. */
} obj_syntax; } obj_syntax;
/** Rules for where a keyword can appear. */ /** DOCDOC */
typedef enum { typedef struct token_rule_t {
DIR = 1, /**< Appears only in directory. */ const char *t; directory_keyword v; arg_syntax s; obj_syntax os;
RTR = 2, /**< Appears only in router descriptor or runningrouters. */ int min_cnt; int max_cnt;
NETSTATUS = 4, /**< v2 or later ("versioned") network status. */ } token_rule_t;
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;
/** Table mapping keywords to token value and to argument rules. */ /** DOCDOC */
static struct { #define END_OF_TABLE { NULL, _NIL, NO_ARGS, NO_OBJ, 0, INT_MAX }
const char *t; directory_keyword v; arg_syntax s; obj_syntax os; int ws; #define T(s,t,a,o) { s, t, a, o, 0, INT_MAX }
} token_table[] = { #define T0N(s,t,a,o) { s, t, a, o, 0, INT_MAX }
{ "accept", K_ACCEPT, ARGS, NO_OBJ, RTR }, #define T1(s,t,a,o) { s, t, a, o, 1, 1 }
{ "directory-signature", K_DIRECTORY_SIGNATURE, ARGS, NEED_OBJ, #define T01(s,t,a,o) { s, t, a, o, 0, 1 }
DIR|NETSTATUS},
{ "r", K_R, ARGS, NO_OBJ, RTRSTATUS }, /** DOCDOC */
{ "s", K_S, ARGS, NO_OBJ, RTRSTATUS }, static token_rule_t routerdesc_token_table[] = {
{ "v", K_V, CONCAT_ARGS, NO_OBJ, RTRSTATUS }, T0N("accept", K_ACCEPT, ARGS, NO_OBJ ),
{ "reject", K_REJECT, ARGS, NO_OBJ, RTR }, T0N("reject", K_REJECT, ARGS, NO_OBJ ),
{ "router", K_ROUTER, ARGS, NO_OBJ, RTR }, T1( "router", K_ROUTER, ARGS, NO_OBJ ),
{ "recommended-software",K_RECOMMENDED_SOFTWARE,ARGS, NO_OBJ, DIR }, T1( "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY ),
{ "signed-directory", K_SIGNED_DIRECTORY, NO_ARGS, NO_OBJ, DIR }, T1( "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY ),
{ "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY,RTR }, T1( "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ ),
{ "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY,RTR }, T1( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
{ "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ,RTR|EXTRAINFO }, T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
{ "running-routers", K_RUNNING_ROUTERS, ARGS, NO_OBJ, DIR }, T01("contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
{ "router-status", K_ROUTER_STATUS, ARGS, NO_OBJ, DIR }, T01("uptime", K_UPTIME, ARGS, NO_OBJ ),
{ "bandwidth", K_BANDWIDTH, ARGS, NO_OBJ, RTR }, T01("family", K_FAMILY, ARGS, NO_OBJ ),
{ "platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ, RTR }, T01("fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
{ "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ, ANYSIGNED|EXTRAINFO }, T01("hibernating", K_HIBERNATING, ARGS, NO_OBJ ),
{ "opt", K_OPT, CONCAT_ARGS, OBJ_OK, ANY }, T01("read-history", K_READ_HISTORY, ARGS, NO_OBJ ),
{ "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ, ANYSIGNED }, T01("write-history", K_WRITE_HISTORY, ARGS, NO_OBJ ),
{ "network-status", K_NETWORK_STATUS, NO_ARGS, NO_OBJ, DIR }, T01("eventdns", K_EVENTDNS, ARGS, NO_OBJ ),
{ "uptime", K_UPTIME, ARGS, NO_OBJ, RTR }, T01("extra-info-digest", K_EXTRA_INFO_DIGEST, ARGS, NO_OBJ ),
{ "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, OBJ_OK, T01("caches-extra-info", K_CACHES_EXTRA_INFO, NO_ARGS, NO_OBJ ),
DIR|NETSTATUS}, T1("bandwidth", K_BANDWIDTH, ARGS, NO_OBJ ),
{ "family", K_FAMILY, ARGS, NO_OBJ, RTR }, T01("platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ ),
{ "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ, ANYSIGNED },
{ "hibernating", K_HIBERNATING, ARGS, NO_OBJ, RTR }, END_OF_TABLE
{ "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 }
}; };
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 function prototypes */
static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok); 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); 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, static directory_token_t *find_first_by_keyword(smartlist_t *s,
directory_keyword keyword); directory_keyword keyword);
static int tokenize_string(const char *start, const char *end, static int tokenize_string(const char *start, const char *end,
smartlist_t *out, where_syntax where); smartlist_t *out,
static directory_token_t *get_next_token(const char **s, where_syntax where); 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, static int check_directory_signature(const char *digest,
directory_token_t *tok, directory_token_t *tok,
crypto_pk_env_t *pkey, crypto_pk_env_t *pkey,
@ -402,7 +446,7 @@ router_parse_directory(const char *str)
} }
++cp; ++cp;
tokens = smartlist_create(); 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; log_warn(LD_DIR, "Error tokenizing directory signature"); goto err;
} }
if (smartlist_len(tokens) != 1) { if (smartlist_len(tokens) != 1) {
@ -431,7 +475,7 @@ router_parse_directory(const char *str)
} }
tokens = smartlist_create(); 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; log_warn(LD_DIR, "Error tokenizing directory"); goto err;
} }
@ -481,7 +525,7 @@ router_parse_runningrouters(const char *str)
goto err; goto err;
} }
tokens = smartlist_create(); 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; log_warn(LD_DIR, "Error tokenizing running-routers"); goto err;
} }
tok = smartlist_get(tokens,0); tok = smartlist_get(tokens,0);
@ -540,7 +584,7 @@ find_dir_signing_key(const char *str)
return NULL; return NULL;
++cp; /* Now cp points to the start of the token. */ ++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) { if (!tok) {
log_warn(LD_DIR, "Unparseable dir-signing-key token"); log_warn(LD_DIR, "Unparseable dir-signing-key token");
return NULL; return NULL;
@ -772,7 +816,7 @@ router_parse_entry_from_string(const char *s, const char *end,
return NULL; return NULL;
} }
tokens = smartlist_create(); 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."); log_warn(LD_DIR, "Error tokeninzing router descriptor.");
goto err; goto err;
} }
@ -1038,7 +1082,7 @@ extrainfo_parse_entry_from_string(const char *s, const char *end,
return NULL; return NULL;
} }
tokens = smartlist_create(); 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."); log_warn(LD_DIR, "Error tokeninzing router descriptor.");
goto err; goto err;
} }
@ -1162,7 +1206,7 @@ routerstatus_parse_entry_from_string(const char **s, smartlist_t *tokens)
eos = find_start_of_next_routerstatus(*s); 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"); log_warn(LD_DIR, "Error tokenizing router status");
goto err; goto err;
} }
@ -1297,6 +1341,7 @@ networkstatus_parse_from_string(const char *s)
{ {
const char *eos; const char *eos;
smartlist_t *tokens = smartlist_create(); smartlist_t *tokens = smartlist_create();
smartlist_t *footer_tokens = smartlist_create();
networkstatus_t *ns = NULL; networkstatus_t *ns = NULL;
char ns_digest[DIGEST_LEN]; char ns_digest[DIGEST_LEN];
char tmp_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); 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."); log_warn(LD_DIR, "Error tokenizing network-status header.");
goto err; goto err;
} }
@ -1433,15 +1478,15 @@ networkstatus_parse_from_string(const char *s)
smartlist_uniq(ns->entries, _compare_routerstatus_entries, smartlist_uniq(ns->entries, _compare_routerstatus_entries,
_free_duplicate_routerstatus_entry); _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."); log_warn(LD_DIR, "Error tokenizing network-status footer.");
goto err; goto err;
} }
if (smartlist_len(tokens) < 1) { if (smartlist_len(footer_tokens) < 1) {
log_warn(LD_DIR, "Too few items in network-status footer."); log_warn(LD_DIR, "Too few items in network-status footer.");
goto err; 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) { if (tok->tp != K_DIRECTORY_SIGNATURE) {
log_warn(LD_DIR, log_warn(LD_DIR,
"Expected network-status footer to end with a signature."); "Expected network-status footer to end with a signature.");
@ -1460,6 +1505,8 @@ networkstatus_parse_from_string(const char *s)
done: done:
SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_free(t)); SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_free(t));
smartlist_free(tokens); smartlist_free(tokens);
SMARTLIST_FOREACH(footer_tokens, directory_token_t *, t, token_free(t));
smartlist_free(footer_tokens);
return ns; return ns;
} }
@ -1494,7 +1541,7 @@ router_parse_addr_policy_from_string(const char *s, int assume_action)
tor_free(tmp); tor_free(tmp);
cp = tmp = new_str; cp = tmp = new_str;
} }
tok = get_next_token(&cp, RTR); tok = get_next_token(&cp, routerdesc_token_table);
if (tok->tp == _ERR) { if (tok->tp == _ERR) {
log_warn(LD_DIR, "Error reading address policy: %s", tok->error); log_warn(LD_DIR, "Error reading address policy: %s", tok->error);
goto err; 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 /** 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 * of the token, and return the parsed token. DOCDOC table
* or RTR, reject all tokens of the wrong type.
*/ */
static directory_token_t * 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; const char *next, *obstart;
int i, done, allocated, is_opt; int i, done, allocated, is_opt;
@ -1710,23 +1756,12 @@ get_next_token(const char **s, where_syntax where)
RET_ERR("opt without keyword"); RET_ERR("opt without keyword");
} }
} }
for (i = 0; token_table[i].t ; ++i) { for (i = 0; table[i].t ; ++i) {
if (!strncmp(token_table[i].t, *s, next-*s)) { if (!strncmp(table[i].t, *s, next-*s)) {
/* We've found the keyword. */ /* We've found the keyword. */
tok->tp = token_table[i].v; tok->tp = table[i].v;
a_syn = token_table[i].s; a_syn = table[i].s;
o_syn = token_table[i].os; o_syn = 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");
}
}
if (a_syn == ARGS) { if (a_syn == ARGS) {
/* This keyword takes multiple arguments. */ /* This keyword takes multiple arguments. */
i = 0; 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 /** 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 * them to <b>out</b>. DOCDOC table.
* tokens; else reject all non-routerdescriptor tokens.
*/ */
static int static int
tokenize_string(const char *start, const char *end, smartlist_t *out, tokenize_string(const char *start, const char *end, smartlist_t *out,
where_syntax where) token_rule_t *table)
{ {
const char **s; const char **s;
directory_token_t *tok = NULL; directory_token_t *tok = NULL;
int counts[_NIL];
int i;
s = &start; s = &start;
if (!end) if (!end)
end = start+strlen(start); 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)) { while (*s < end && (!tok || tok->tp != _EOF)) {
tok = get_next_token(s, where); tok = get_next_token(s, table);
if (tok->tp == _ERR) { if (tok->tp == _ERR) {
log_warn(LD_DIR, "parse error: %s", tok->error); log_warn(LD_DIR, "parse error: %s", tok->error);
return -1; return -1;
} }
++counts[tok->tp];
smartlist_add(out, tok); smartlist_add(out, tok);
*s = eat_whitespace(*s); *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; return 0;
} }