tor/src/feature/control/control_proto.c

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/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2019, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file control_proto.c
* \brief Formatting functions for controller data.
*/
#include "core/or/or.h"
#include "core/mainloop/connection.h"
#include "core/or/circuitbuild.h"
#include "core/or/circuitlist.h"
#include "core/or/connection_edge.h"
#include "feature/control/control_proto.h"
#include "feature/nodelist/nodelist.h"
#include "core/or/cpath_build_state_st.h"
#include "core/or/entry_connection_st.h"
#include "core/or/or_connection_st.h"
#include "core/or/origin_circuit_st.h"
#include "core/or/socks_request_st.h"
#include "feature/control/control_connection_st.h"
/** Append a NUL-terminated string <b>s</b> to the end of
* <b>conn</b>-\>outbuf.
*/
void
connection_write_str_to_buf(const char *s, control_connection_t *conn)
{
size_t len = strlen(s);
connection_buf_add(s, len, TO_CONN(conn));
}
/** Acts like sprintf, but writes its formatted string to the end of
* <b>conn</b>-\>outbuf. */
void
connection_printf_to_buf(control_connection_t *conn, const char *format, ...)
{
va_list ap;
char *buf = NULL;
int len;
va_start(ap,format);
len = tor_vasprintf(&buf, format, ap);
va_end(ap);
if (len < 0) {
log_err(LD_BUG, "Unable to format string for controller.");
tor_assert(0);
}
connection_buf_add(buf, (size_t)len, TO_CONN(conn));
tor_free(buf);
}
/** Given a <b>len</b>-character string in <b>data</b>, made of lines
* terminated by CRLF, allocate a new string in *<b>out</b>, and copy the
* contents of <b>data</b> into *<b>out</b>, adding a period before any period
* that appears at the start of a line, and adding a period-CRLF line at
* the end. Replace all LF characters sequences with CRLF. Return the number
* of bytes in *<b>out</b>.
*
* This corresponds to CmdData in control-spec.txt.
*/
size_t
write_escaped_data(const char *data, size_t len, char **out)
{
tor_assert(len < SIZE_MAX - 9);
size_t sz_out = len+8+1;
char *outp;
const char *start = data, *end;
size_t i;
int start_of_line;
for (i=0; i < len; ++i) {
if (data[i] == '\n') {
sz_out += 2; /* Maybe add a CR; maybe add a dot. */
if (sz_out >= SIZE_T_CEILING) {
log_warn(LD_BUG, "Input to write_escaped_data was too long");
*out = tor_strdup(".\r\n");
return 3;
}
}
}
*out = outp = tor_malloc(sz_out);
end = data+len;
start_of_line = 1;
while (data < end) {
if (*data == '\n') {
if (data > start && data[-1] != '\r')
*outp++ = '\r';
start_of_line = 1;
} else if (*data == '.') {
if (start_of_line) {
start_of_line = 0;
*outp++ = '.';
}
} else {
start_of_line = 0;
}
*outp++ = *data++;
}
if (outp < *out+2 || fast_memcmp(outp-2, "\r\n", 2)) {
*outp++ = '\r';
*outp++ = '\n';
}
*outp++ = '.';
*outp++ = '\r';
*outp++ = '\n';
*outp = '\0'; /* NUL-terminate just in case. */
tor_assert(outp >= *out);
tor_assert((size_t)(outp - *out) <= sz_out);
return outp - *out;
}
/** Given a <b>len</b>-character string in <b>data</b>, made of lines
* terminated by CRLF, allocate a new string in *<b>out</b>, and copy
* the contents of <b>data</b> into *<b>out</b>, removing any period
* that appears at the start of a line, and replacing all CRLF sequences
* with LF. Return the number of
* bytes in *<b>out</b>.
*
* This corresponds to CmdData in control-spec.txt.
*/
size_t
read_escaped_data(const char *data, size_t len, char **out)
{
char *outp;
const char *next;
const char *end;
*out = outp = tor_malloc(len+1);
end = data+len;
while (data < end) {
/* we're at the start of a line. */
if (*data == '.')
++data;
next = memchr(data, '\n', end-data);
if (next) {
size_t n_to_copy = next-data;
/* Don't copy a CR that precedes this LF. */
if (n_to_copy && *(next-1) == '\r')
--n_to_copy;
memcpy(outp, data, n_to_copy);
outp += n_to_copy;
data = next+1; /* This will point at the start of the next line,
* or the end of the string, or a period. */
} else {
memcpy(outp, data, end-data);
outp += (end-data);
*outp = '\0';
return outp - *out;
}
*outp++ = '\n';
}
*outp = '\0';
return outp - *out;
}
/** Send a "DONE" message down the control connection <b>conn</b>. */
void
send_control_done(control_connection_t *conn)
{
2019-04-11 00:04:09 +02:00
control_write_endreply(conn, 250, "OK");
}
/** Write a reply to the control channel.
*
* @param conn control connection
* @param code numeric result code
* @param c separator character, usually ' ', '-', or '+'
* @param s string
*/
MOCK_IMPL(void,
control_write_reply, (control_connection_t *conn, int code, int c,
const char *s))
{
connection_printf_to_buf(conn, "%03d%c%s\r\n", code, c, s);
}
/** Write a formatted reply to the control channel.
*
* @param conn control connection
* @param code numeric result code
* @param c separator character, usually ' ', '-', or '+'
* @param fmt format string
* @param ap va_list from caller
*/
void
control_vprintf_reply(control_connection_t *conn, int code, int c,
const char *fmt, va_list ap)
{
char *buf = NULL;
int len;
len = tor_vasprintf(&buf, fmt, ap);
if (len < 0) {
log_err(LD_BUG, "Unable to format string for controller.");
tor_assert(0);
}
control_write_reply(conn, code, c, buf);
tor_free(buf);
}
/** Write an EndReplyLine */
void
control_write_endreply(control_connection_t *conn, int code, const char *s)
{
control_write_reply(conn, code, ' ', s);
}
/** Write a formatted EndReplyLine */
void
control_printf_endreply(control_connection_t *conn, int code,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
control_vprintf_reply(conn, code, ' ', fmt, ap);
va_end(ap);
}
/** Write a MidReplyLine */
void
control_write_midreply(control_connection_t *conn, int code, const char *s)
{
control_write_reply(conn, code, '-', s);
}
/** Write a formatted MidReplyLine */
void
control_printf_midreply(control_connection_t *conn, int code, const char *fmt,
...)
{
va_list ap;
va_start(ap, fmt);
control_vprintf_reply(conn, code, '-', fmt, ap);
va_end(ap);
}
/** Write a DataReplyLine */
void
control_write_datareply(control_connection_t *conn, int code, const char *s)
{
control_write_reply(conn, code, '+', s);
}
/** Write a formatted DataReplyLine */
void
control_printf_datareply(control_connection_t *conn, int code, const char *fmt,
...)
{
va_list ap;
va_start(ap, fmt);
control_vprintf_reply(conn, code, '+', fmt, ap);
va_end(ap);
}
/** Write a CmdData */
void
control_write_data(control_connection_t *conn, const char *data)
{
char *esc = NULL;
size_t esc_len;
esc_len = write_escaped_data(data, strlen(data), &esc);
connection_buf_add(esc, esc_len, TO_CONN(conn));
tor_free(esc);
}