Mercurial > dnsbl
diff src/scanner.cpp @ 19:b8f5fa3dd5b8
fix problems in the state transitions causing impossible states
| author | carl |
|---|---|
| date | Fri, 30 Apr 2004 22:44:56 -0700 |
| parents | 041ea016b684 |
| children | 06de5ab6a232 |
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--- a/src/scanner.cpp Fri Apr 30 00:32:44 2004 -0700 +++ b/src/scanner.cpp Fri Apr 30 22:44:56 2004 -0700 @@ -35,7 +35,7 @@ // counter for number of columns in the table end_state, - // temporary mime states + // temporary states h_end, t_end, u_reco, @@ -134,7 +134,7 @@ {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x50 P {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x51 Q {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x52 R - {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x53 S + {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x53 S {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x54 T {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x55 U {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x56 V @@ -166,7 +166,7 @@ {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x70 p {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x71 q {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x72 r - {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x73 s + {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x73 s {h_host, h_host, t_init, t_disc, u_http, u_http, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x74 t {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x75 u {h_host, h_host, t_init, t_disc, u_init, u_init, u_url, u_url, e_init, e_init, e_init, m_init, m_init, m_init, b_init, b_64, b_64, b_64, }, // 0x76 v @@ -849,6 +849,7 @@ fsa(state init, fsa* next1_, fsa* next2_, string_set *hosts_); void push(u_char *buf, int len); void pusher(); + void error(char *err); }; fsa::fsa(state init_, fsa *next1_, fsa *next2_, string_set *hosts_) { @@ -860,6 +861,12 @@ hosts = hosts_; } +void fsa::error(char *err) { + count = 0; + st = init; + if (err) my_syslog(err); +} + void fsa::pusher() { if (next1) next1->push(pending, count); if (next2) next2->push(pending, count); @@ -868,12 +875,9 @@ void fsa::push(u_char *buf, int len) { for (int i=0; i<len; i++) { + if (count == (PENDING_LIMIT-1)) error(NULL); + if (st >= end_state) error("finite state machine impossible state"); u_char c = buf[i]; - // guard against buffer overflow - if (count == (PENDING_LIMIT-1)) { - pusher(); - st = init; - } pending[count++] = c; st = parse_table[c][st]; switch (st) { @@ -892,6 +896,7 @@ } } } + st = h_init; } // fall thru case h_init: { @@ -915,20 +920,25 @@ ////////////////////////////// // url recognizer case u_sla: { - if ((count < 6) || (7 < count)) { + if ((count < 6) || (8 < count)) { // allow http:// or https:// count = 0; st = u_init; } } break; case u_reco: { - if (count > 12) { - pending[count-1] = 0; + if (count > 13) { // need some minimal length host name after the protocol + pending[--count] = '\0'; // null terminate host name by overwriting the terminator + char *p = NULL; if (strncasecmp((const char *)pending, "http://", 7) == 0) { - char *p = (char *)pending + 7; - if (strchr(p, '.')) register_string(*hosts, p); // require at least one . in a dns name + p = (char *)pending + 7; } + if (strncasecmp((const char *)pending, "https://", 8) == 0) { + p = (char *)pending + 8; } + if (p && strchr(p, '.')) register_string(*hosts, p); // require at least one . in a dns name + } + st = u_init; } // fall thru case u_init: {