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Diffstat (limited to 'src/feature/control/control_proto.c')
| -rw-r--r-- | src/feature/control/control_proto.c | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/src/feature/control/control_proto.c b/src/feature/control/control_proto.c new file mode 100644 index 0000000000..98715ad9d5 --- /dev/null +++ b/src/feature/control/control_proto.c @@ -0,0 +1,434 @@ +/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, 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" +#include "lib/container/smartlist.h" +#include "lib/encoding/kvline.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) +{ + 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 reply content + */ +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); +} + +/** Write a single reply line to @a conn. + * + * @param conn control connection + * @param line control reply line to write + * @param lastone true if this is the last reply line of a multi-line reply + */ +void +control_write_reply_line(control_connection_t *conn, + const control_reply_line_t *line, bool lastone) +{ + const config_line_t *kvline = line->kvline; + char *s = NULL; + + if (strpbrk(kvline->value, "\r\n") != NULL) { + /* If a key-value pair needs to be encoded as CmdData, it can be + the only key-value pair in that reply line */ + tor_assert(kvline->next == NULL); + control_printf_datareply(conn, line->code, "%s=", kvline->key); + control_write_data(conn, kvline->value); + return; + } + s = kvline_encode(kvline, line->flags); + if (lastone) { + control_write_endreply(conn, line->code, s); + } else { + control_write_midreply(conn, line->code, s); + } + tor_free(s); +} + +/** Write a set of reply lines to @a conn. + * + * @param conn control connection + * @param lines smartlist of pointers to control_reply_line_t to write + */ +void +control_write_reply_lines(control_connection_t *conn, smartlist_t *lines) +{ + bool lastone = false; + + SMARTLIST_FOREACH_BEGIN(lines, control_reply_line_t *, line) { + if (line_sl_idx >= line_sl_len - 1) + lastone = true; + control_write_reply_line(conn, line, lastone); + } SMARTLIST_FOREACH_END(line); +} + +/** Add a single key-value pair as a new reply line to a control reply + * line list. + * + * @param reply smartlist of pointers to control_reply_line_t + * @param code numeric control reply code + * @param flags kvline encoding flags + * @param key key + * @param val value + */ +void +control_reply_add_one_kv(smartlist_t *reply, int code, int flags, + const char *key, const char *val) +{ + control_reply_line_t *line = tor_malloc_zero(sizeof(*line)); + + line->code = code; + line->flags = flags; + config_line_append(&line->kvline, key, val); + smartlist_add(reply, line); +} + +/** Append a single key-value pair to last reply line in a control + * reply line list. + * + * @param reply smartlist of pointers to control_reply_line_t + * @param key key + * @param val value + */ +void +control_reply_append_kv(smartlist_t *reply, const char *key, const char *val) +{ + int len = smartlist_len(reply); + control_reply_line_t *line; + + tor_assert(len > 0); + + line = smartlist_get(reply, len - 1); + config_line_append(&line->kvline, key, val); +} + +/** Add new reply line consisting of the string @a s + * + * @param reply smartlist of pointers to control_reply_line_t + * @param code numeric control reply code + * @param s string containing the rest of the reply line + */ +void +control_reply_add_str(smartlist_t *reply, int code, const char *s) +{ + control_reply_add_one_kv(reply, code, KV_OMIT_KEYS|KV_RAW, "", s); +} + +/** Format a new reply line + * + * @param reply smartlist of pointers to control_reply_line_t + * @param code numeric control reply code + * @param fmt format string + */ +void +control_reply_add_printf(smartlist_t *reply, int code, const char *fmt, ...) +{ + va_list ap; + char *buf = NULL; + + va_start(ap, fmt); + (void)tor_vasprintf(&buf, fmt, ap); + va_end(ap); + control_reply_add_str(reply, code, buf); + tor_free(buf); +} + +/** Add a "250 OK" line to a set of control reply lines */ +void +control_reply_add_done(smartlist_t *reply) +{ + control_reply_add_str(reply, 250, "OK"); +} + +/** Free a control_reply_line_t. Don't call this directly; use the + * control_reply_line_free() macro instead. */ +void +control_reply_line_free_(control_reply_line_t *line) +{ + if (!line) + return; + config_free_lines(line->kvline); + tor_free_(line); +} + +/** Clear a smartlist of control_reply_line_t. Doesn't free the + * smartlist, but does free each individual line. */ +void +control_reply_clear(smartlist_t *reply) +{ + SMARTLIST_FOREACH(reply, control_reply_line_t *, line, + control_reply_line_free(line)); + smartlist_clear(reply); +} + +/** Free a smartlist of control_reply_line_t. Don't call this + * directly; use the control_reply_free() macro instead. */ +void +control_reply_free_(smartlist_t *reply) +{ + control_reply_clear(reply); + smartlist_free_(reply); +} |