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psyced/world/net/spyc/parse.c
PSYC a3560ed43a +
2011-06-01 00:02:33 +02:00

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// vim:foldmethod=marker:syntax=lpc:noexpandtab
// $Id: parse.c,v 1.30 2008/12/18 18:16:14 lynx Exp $
#include "psyc.h"
#ifdef LIBPSYC // net/spyc currently doesn't work without libpsyc
// and probably never will.. will delete the old code soon
#include <net.h>
#include <input_to.h>
private string buffer;
int state;
int may_parse_more;
#ifndef LIBPSYC
private string body_buffer;
int body_len;
// temporary used to hold assigment lists vname -> ({ glyph, state, vvalue })
// this won't work anymore, dispatch now expects two mappings: rvars & evars
array(mixed) tvars;
mapping hvars;
// prototypes
parse_header();
buffer_content();
#endif // LIBPSYC
// being faded out in favor of regular croak()
#define PARSEERROR(reason) { \
croak("_error_syntax_broken", \
"Failed parsing: " reason); \
return 0; }
#define DELIM S_GLYPH_PACKET_DELIMITER "\n"
#define C_LINEFEED '\n'
#define MVAR_GLYPH 0
#define MVAR_STATE 1
#define MVAR_VALUE 2
#ifndef PSYC_UDP
# define QUIT remove_interactive(ME); return 0;
#endif
step(); // prototype
// overload this as needed
varargs mixed croak(string mc, string data, vamapping vars) { return 0; }
#ifndef LIBPSYC
// reset parser state
void parser_reset() {
if (state != PSYCPARSE_STATE_BLOCKED)
state = PSYCPARSE_STATE_HEADER;
body_len = 0;
body_buffer = 0;
may_parse_more = 1;
tvars = ({ });
hvars = ([ ]);
}
#endif
// initialize the parser
void parser_init() {
# ifndef LIBPSYC
parser_reset();
# endif
buffer = "";
state = PSYCPARSE_STATE_GREET; // AFTER reset
}
// it is sometimes useful to stop parsing
void interrupt_parse() {
state = PSYCPARSE_STATE_BLOCKED;
}
// and resume after some blocking operation is done
void resume_parse() {
state = PSYCPARSE_STATE_HEADER;
}
// called when a complete packet has arrived
void dispatch(mapping rvars, mapping evars, mixed method, mixed body) {
#ifndef LIBPSYC
parser_reset();
#endif
}
void psyc_dispatch(mixed p) {
if (p[PACKET_METHOD] && p[PACKET_METHOD][0] != '_') {
log_file("SPYC", "%O SYNTAX %O\n", query_ip_name(), p);
croak("_error_invalid_method_compact",
"Compact methods undefined as yet.");
QUIT
}
dispatch(p[PACKET_ROUTING], p[PACKET_ENTITY], p[PACKET_METHOD], p[PACKET_BODY]);
}
// respond to the first empty packet
void first_response() {
P0(("parser::first_response called. overload this!"))
}
// input data to the buffer
void feed(string data) {
P4((">> feed: %O\n", data));
# ifdef _flag_log_sockets_SPYC
log_file("RAW_SPYC", "» %O\n%s\n", ME, data);
# endif
buffer += data;
# ifndef LIBPSYC
do {
may_parse_more = 0;
step();
} while (may_parse_more);
# else
if (state != PSYCPARSE_STATE_HEADER)
step();
if (state == PSYCPARSE_STATE_HEADER) {
switch (psyc_parse(buffer)) {
case 0: // success
break;
case PSYC_PARSE_ERROR_AMOUNT:
croak("_error_invalid_amount");
QUIT
case PSYC_PARSE_ERROR_DEGREE:
croak("_error_invalid_degree");
QUIT
case PSYC_PARSE_ERROR_DATE:
croak("_error_invalid_date");
QUIT
case PSYC_PARSE_ERROR_TIME:
croak("_error_invalid_time");
QUIT
case PSYC_PARSE_ERROR_FLAG:
croak("_error_invalid_flag");
QUIT
case PSYC_PARSE_ERROR_LIST:
croak("_error_invalid_list");
QUIT
case PSYC_PARSE_ERROR_LIST_TOO_LARGE:
croak("_error_list_too_large");
QUIT
default: // parse error
croak("_error_invalid_syntax");
}
buffer = "";
}
# endif
}
// parser stepping function
void step() {
P3(("%O step: state %O, buffer %O\n", ME, state, buffer))
if (!strlen(buffer))
return;
switch(state) {
#ifndef LIBPSYC
case PSYCPARSE_STATE_HEADER:
parse_header();
break;
case PSYCPARSE_STATE_CONTENT:
buffer_content();
break;
#endif
case PSYCPARSE_STATE_BLOCKED:
// someone requested to stop parsing - e.g. _request_features circuit
// message
break;
case PSYCPARSE_STATE_GREET: // wait for greeting
if (strlen(buffer) < 2)
return;
if (buffer[0..1] == DELIM) {
state = PSYCPARSE_STATE_HEADER;
buffer = buffer[2 ..];
first_response();
#ifndef LIBPSYC
step();
#endif
} else {
croak("_error_syntax_initialization");
// "The new protocol begins with a pipe and a line feed.");
}
break;
default: // uhm... if we ever get here this is the programmers fault
break;
}
}
// EOF for LIBPSYC
#ifndef LIBPSYC
// processes routing header variable assignments
// basic version does no state
mapping process_header(mixed varops) {
mapping vars = ([ ]);
// apply mmp state
foreach(mixed vop : varops) {
string vname = vop[0];
switch(vop[1]) {
case C_GLYPH_MODIFIER_SET:
vars[vname] = vop[2];
break;
case C_GLYPH_MODIFIER_AUGMENT:
case C_GLYPH_MODIFIER_DIMINISH:
case C_GLYPH_MODIFIER_QUERY:
case C_GLYPH_MODIFIER_ASSIGN:
croak("_failure_unavailable_state");
QUIT
default:
croak("_failure_unknown_glyph");
QUIT
}
// FIXME: not every legal varname is a routing varname
// look at shared_memory("routing")
if (!legal_keyword(vname) || abbrev("_INTERNAL", vname)) {
croak("_error_illegal_protocol_variable", 0,
([ "_variable_name": vname ]));
return 0;
}
}
return vars;
}
// parse the header part of the packet
// i.e. that is all mmp modifiers
// switch to content buffering mode afterwards
void parse_header() {
if (!strlen(buffer)) return;
if (buffer[0] == C_GLYPH_PACKET_DELIMITER) {
if (strlen(buffer) < 2)
return;
if (buffer[1] == C_LINEFEED) {
buffer = buffer[2..];
hvars = process_header(tvars);
tvars = ({ });
dispatch(hvars, tvars, 0, 0);
} else {
// this one is sth like |whatever
// actually this should be noglyph i think
PARSEERROR("strange thing")
}
} else if (buffer[0] == C_LINEFEED) {
// state transition from parsing header to buffering body
buffer = buffer[1..];
hvars = process_header(tvars);
tvars = ({ });
// FIXME: validate source/context here
state = PSYCPARSE_STATE_CONTENT;
if (hvars["_length"])
body_len = to_int(hvars["_length"][MVAR_VALUE]);
step();
} else { // parse mmp-header
int fit;
int glyph;
string vname, vvalue;
switch(buffer[0]) {
case C_GLYPH_MODIFIER_SET:
case C_GLYPH_MODIFIER_ASSIGN:
case C_GLYPH_MODIFIER_AUGMENT:
case C_GLYPH_MODIFIER_DIMINISH:
case C_GLYPH_MODIFIER_QUERY:
glyph = buffer[0];
buffer = buffer[1..];
break;
default:
croak("_error_syntax_expected_routing");
QUIT
}
fit = sscanf(buffer, "%.1s%t", vname);
if (fit != 1) {
PARSEERROR("vname")
}
buffer = buffer[strlen(vname)..];
switch(buffer[0]) {
case '\t':
fit = sscanf(buffer, "\t%s\n%.0s", vvalue, buffer);
if (fit != 2) {
PARSEERROR("simple-arg")
}
break;
case '\n': // deletion
// this is currently implemented as "vvalue is 0" internally
// and must handled in dispatch() when merging
buffer = buffer[1..];
break;
default:
PARSEERROR("arg")
}
tvars += ({ ({ vname, glyph, vvalue }) });
step();
}
}
// parse all psyc-modifiers
// this differes from the mmp modifiers in the sense that
// a) packet is known to be complete here
// b) psyc modifiers may have binary args
void parse_psyc() {
while(1) { // slurp in all psyc-modifiers
int fit, len;
int glyph;
string vname, vvalue;
switch(body_buffer[0]) {
case C_GLYPH_MODIFIER_SET:
case C_GLYPH_MODIFIER_ASSIGN:
case C_GLYPH_MODIFIER_AUGMENT:
case C_GLYPH_MODIFIER_DIMINISH:
case C_GLYPH_MODIFIER_QUERY:
glyph = body_buffer[0];
body_buffer = body_buffer[1..];
break;
default:
// this is the method
return;
}
fit = sscanf(body_buffer, "%.1s%t", vname);
if (fit != 1) {
PARSEERROR("vname")
}
body_buffer = body_buffer[strlen(vname)..];
switch(body_buffer[0]) {
case ' ':
fit = sscanf(body_buffer, " %d\t%.0s", len, body_buffer);
if (fit != 2) {
PARSEERROR("binary-arg length")
}
if (len < 0) {
PARSEERROR("negative binary length")
}
if (strlen(body_buffer) < len) {
// ouch, this is a problem here
PARSEERROR("not enough to read binary arg, may not happen")
}
vvalue = body_buffer[..len-1];
body_buffer = body_buffer[len..];
if (body_buffer[0] != C_LINEFEED) {
PARSEERROR("binary terminal")
}
body_buffer = body_buffer[1..];
break;
case '\t':
fit = sscanf(body_buffer, "\t%s\n%.0s", vvalue, body_buffer);
if (fit != 2) {
PARSEERROR("simple-arg")
}
break;
case '\n':
switch(glyph) {
case C_GLYPH_MODIFIER_ASSIGN:
// delete this context's state
PARSEERROR("tbd")
// unfortunately the routing hasn't been processed at
// this moment yet, so we don't know whose context this
// is and if it is legitimate. we first have to fix the
// processing of the routing layer before we can implement
// anything of this
continue;
case C_GLYPH_MODIFIER_SET:
// remember to temporarily ignore state
PARSEERROR("tbd")
continue;
case C_GLYPH_MODIFIER_QUERY:
// mark that the next reply packet should
// contain a state sync
PARSEERROR("tbd")
continue;
default:
PARSEERROR("undefined operation")
}
return;
default:
PARSEERROR("arg")
}
tvars += ({ ({ vname, glyph, vvalue }) });
}
}
// parse completed content
void parse_content() {
int fit;
string method, body;
// at this point we should check for relaying, then potentially
// route the data without parsing it.. TODO
parse_psyc();
// ASSERT strlen(buffer)
if (body_buffer[0] == C_LINEFEED) {
PARSEERROR("empty method")
}
// FIXME: i am not sure if this is correct...
if (body_buffer == S_GLYPH_PACKET_DELIMITER) {
P0(("encountered packet delimiter in packet body? how's that?\n"))
dispatch(hvars, tvars, 0, 0);
return;
}
fit = sscanf(body_buffer, "%.1s\n%.0s", method, body_buffer);
if (fit != 2 || !legal_keyword(method)) {
croak("_error_illegal_method");
// "That's not a valid method name.");
return;
}
// mhmm... why does body_buffer still contain the newline?
// because the newline is by definition not part of the body!
if (strlen(body_buffer)) body = body_buffer[..<2];
dispatch(hvars, tvars, method, body);
}
// buffer content until complete
// then parse it
// note: you could overload this, if you just want to route
// the packet
void buffer_content() {
int t;
if (body_len) {
if (strlen(buffer) >= body_len + 3) {
// make sure that the packet is properly terminated
if (buffer[body_len..body_len+2] != "\n" DELIM) {
PARSEERROR("packet delimiter after binary body not found")
}
body_buffer = buffer[..body_len];
buffer = buffer[body_len+3..];
parse_content();
} else {
P4(("buffer_content: waiting for more binary data\n"))
}
} else if ((t = strstr(buffer, "\n" DELIM)) != -1) {
body_buffer = buffer[..t];
buffer = buffer[t+3..];
parse_content();
P4(("buffer_content: packet complete\n"))
} else {
P4(("buffer_content: waiting for more plain data. buffer %O vs %O\n", to_array(buffer), to_array("\n" DELIM)))
}
}
// FIXME should be in a standalone module
//#define PARSEERROR(args) debug_message(sprintf("LIST PARSE ERROR: " args));
#define LISTSEP '|'
#define LISTPARSE_FAIL -1
#define LISTMODE_PLAIN 0
#define LISTMODE_BINARY 1
// list parsing function - val is assumed to be stripped of the final LF
mixed list_parse(string val) {
mixed *lv = ({ });
if (val[0] == LISTSEP)
return explode(val[1..], "|");
while(strlen(val)) {
int fit, len;
fit = sscanf(val, "%d %s", len, val);
if (fit != 2) {
// invalid binary fit
return LISTPARSE_FAIL;
}
if (len < 0 || len > strlen(val)) {
// invalid binary length
return LISTPARSE_FAIL;
}
if (len != strlen(val) && val[len] != LISTSEP) {
// listsep not found after binary
return LISTPARSE_FAIL;
}
lv += ({ val[..len-1] });
val = val[len+1..];
}
return lv;
}
# ifdef SELFTESTS
test() {
list_parse("|psyc://example.net/~jim|psyc://example.org/~judy");
list_parse("5\tabcde|4\tabcd");
}
# endif
#endif // !LIBPSYC
#endif // LIBPSYC
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