Merge remote-tracking branch 'tor-github/pr/1505'

4 files changed, 326 insertions, 90 deletions

diff --git a/src/feature/control/control_cmd.c b/src/feature/control/control_cmd.c
index 656ddf5ca1..cc4375112f 100644
--- a/src/feature/control/control_cmd.c
+++ b/src/feature/control/control_cmd.c
@@ -289,26 +289,23 @@ handle_control_getconf(control_connection_t *conn,
   const smartlist_t *questions = args->args;
   smartlist_t *answers = smartlist_new();
   smartlist_t *unrecognized = smartlist_new();
-  char *msg = NULL;
-  size_t msg_len;
   const or_options_t *options = get_options();
-  int i, len;
 
   SMARTLIST_FOREACH_BEGIN(questions, const char *, q) {
     if (!option_is_recognized(q)) {
-      smartlist_add(unrecognized, (char*) q);
+      control_reply_add_printf(unrecognized, 552,
+                               "Unrecognized configuration key \"%s\"", q);
     } else {
       config_line_t *answer = option_get_assignment(options,q);
       if (!answer) {
         const char *name = option_get_canonical_name(q);
-        smartlist_add_asprintf(answers, "250-%s\r\n", name);
+        control_reply_add_one_kv(answers, 250, KV_OMIT_VALS, name, "");
       }
 
       while (answer) {
         config_line_t *next;
-        smartlist_add_asprintf(answers, "250-%s=%s\r\n",
-                     answer->key, answer->value);
-
+        control_reply_add_one_kv(answers, 250, KV_RAW, answer->key,
+                                 answer->value);
         next = answer->next;
         tor_free(answer->key);
         tor_free(answer->value);
@@ -318,20 +315,10 @@ handle_control_getconf(control_connection_t *conn,
     }
   } SMARTLIST_FOREACH_END(q);
 
-  if ((len = smartlist_len(unrecognized))) {
-    for (i=0; i < len-1; ++i)
-      control_printf_midreply(conn, 552,
-                              "Unrecognized configuration key \"%s\"",
-                              (char*)smartlist_get(unrecognized, i));
-    control_printf_endreply(conn, 552,
-                            "Unrecognized configuration key \"%s\"",
-                            (char*)smartlist_get(unrecognized, len-1));
-  } else if ((len = smartlist_len(answers))) {
-    char *tmp = smartlist_get(answers, len-1);
-    tor_assert(strlen(tmp)>4);
-    tmp[3] = ' ';
-    msg = smartlist_join_strings(answers, "", 0, &msg_len);
-    connection_buf_add(msg, msg_len, TO_CONN(conn));
+  if (smartlist_len(unrecognized)) {
+    control_write_reply_lines(conn, unrecognized);
+  } else if (smartlist_len(answers)) {
+    control_write_reply_lines(conn, answers);
   } else {
     send_control_done(conn);
   }
@@ -340,8 +327,6 @@ handle_control_getconf(control_connection_t *conn,
   smartlist_free(answers);
   smartlist_free(unrecognized);
 
-  tor_free(msg);
-
   return 0;
 }
 
@@ -1257,6 +1242,66 @@ static const control_cmd_syntax_t protocolinfo_syntax = {
   .max_args = UINT_MAX
 };
 
+/** Return a comma-separated list of authentication methods for
+    handle_control_protocolinfo().  Caller must free this string. */
+static char *
+get_authmethods(const or_options_t *options)
+{
+  int cookies = options->CookieAuthentication;
+  char *methods;
+  int passwd = (options->HashedControlPassword != NULL ||
+                options->HashedControlSessionPassword != NULL);
+  smartlist_t *mlist = smartlist_new();
+
+  if (cookies) {
+    smartlist_add(mlist, (char*)"COOKIE");
+    smartlist_add(mlist, (char*)"SAFECOOKIE");
+  }
+  if (passwd)
+    smartlist_add(mlist, (char*)"HASHEDPASSWORD");
+  if (!cookies && !passwd)
+    smartlist_add(mlist, (char*)"NULL");
+  methods = smartlist_join_strings(mlist, ",", 0, NULL);
+  smartlist_free(mlist);
+
+  return methods;
+}
+
+/** Return escaped cookie filename.  Caller must free this string.
+    Return NULL if cookie authentication is disabled. */
+static char *
+get_esc_cfile(const or_options_t *options)
+{
+  char *cfile = NULL, *abs_cfile = NULL, *esc_cfile = NULL;
+
+  if (!options->CookieAuthentication)
+    return NULL;
+
+  cfile = get_controller_cookie_file_name();
+  abs_cfile = make_path_absolute(cfile);
+  esc_cfile = esc_for_log(abs_cfile);
+  tor_free(cfile);
+  tor_free(abs_cfile);
+  return esc_cfile;
+}
+
+/** Compose the auth methods line of a PROTOCOLINFO reply. */
+static void
+add_authmethods(smartlist_t *reply)
+{
+  const or_options_t *options = get_options();
+  char *methods = get_authmethods(options);
+  char *esc_cfile = get_esc_cfile(options);
+
+  control_reply_add_str(reply, 250, "AUTH");
+  control_reply_append_kv(reply, "METHODS", methods);
+  if (esc_cfile)
+    control_reply_append_kv(reply, "COOKIEFILE", esc_cfile);
+
+  tor_free(methods);
+  tor_free(esc_cfile);
+}
+
 /** Called when we get a PROTOCOLINFO command: send back a reply. */
 static int
 handle_control_protocolinfo(control_connection_t *conn,
@@ -1264,6 +1309,7 @@ handle_control_protocolinfo(control_connection_t *conn,
 {
   const char *bad_arg = NULL;
   const smartlist_t *args = cmd_args->args;
+  smartlist_t *reply = NULL;
 
   conn->have_sent_protocolinfo = 1;
 
@@ -1281,45 +1327,17 @@ handle_control_protocolinfo(control_connection_t *conn,
     /* Don't tolerate bad arguments when not authenticated. */
     if (!STATE_IS_OPEN(TO_CONN(conn)->state))
       connection_mark_for_close(TO_CONN(conn));
-    goto done;
-  } else {
-    const or_options_t *options = get_options();
-    int cookies = options->CookieAuthentication;
-    char *cfile = get_controller_cookie_file_name();
-    char *abs_cfile;
-    char *esc_cfile;
-    char *methods;
-    abs_cfile = make_path_absolute(cfile);
-    esc_cfile = esc_for_log(abs_cfile);
-    {
-      int passwd = (options->HashedControlPassword != NULL ||
-                    options->HashedControlSessionPassword != NULL);
-      smartlist_t *mlist = smartlist_new();
-      if (cookies) {
-        smartlist_add(mlist, (char*)"COOKIE");
-        smartlist_add(mlist, (char*)"SAFECOOKIE");
-      }
-      if (passwd)
-        smartlist_add(mlist, (char*)"HASHEDPASSWORD");
-      if (!cookies && !passwd)
-        smartlist_add(mlist, (char*)"NULL");
-      methods = smartlist_join_strings(mlist, ",", 0, NULL);
-      smartlist_free(mlist);
-    }
-
-    control_write_midreply(conn, 250, "PROTOCOLINFO 1");
-    control_printf_midreply(conn, 250, "AUTH METHODS=%s%s%s", methods,
-                            cookies?" COOKIEFILE=":"",
-                            cookies?esc_cfile:"");
-    control_printf_midreply(conn, 250, "VERSION Tor=%s", escaped(VERSION));
-    send_control_done(conn);
-
-    tor_free(methods);
-    tor_free(cfile);
-    tor_free(abs_cfile);
-    tor_free(esc_cfile);
+    return 0;
   }
- done:
+  reply = smartlist_new();
+  control_reply_add_str(reply, 250, "PROTOCOLINFO 1");
+  add_authmethods(reply);
+  control_reply_add_str(reply, 250, "VERSION");
+  control_reply_append_kv(reply, "Tor", escaped(VERSION));
+  control_reply_add_done(reply);
+
+  control_write_reply_lines(conn, reply);
+  control_reply_free(reply);
   return 0;
 }
 
diff --git a/src/feature/control/control_getinfo.c b/src/feature/control/control_getinfo.c
index 979fa4480d..cff4a08793 100644
--- a/src/feature/control/control_getinfo.c
+++ b/src/feature/control/control_getinfo.c
@@ -50,6 +50,7 @@
 #include "feature/stats/geoip_stats.h"
 #include "feature/stats/predict_ports.h"
 #include "lib/version/torversion.h"
+#include "lib/encoding/kvline.h"
 
 #include "core/or/entry_connection_st.h"
 #include "core/or/or_connection_st.h"
@@ -1632,7 +1633,6 @@ handle_control_getinfo(control_connection_t *conn,
   smartlist_t *answers = smartlist_new();
   smartlist_t *unrecognized = smartlist_new();
   char *ans = NULL;
-  int i;
 
   SMARTLIST_FOREACH_BEGIN(questions, const char *, q) {
     const char *errmsg = NULL;
@@ -1644,43 +1644,32 @@ handle_control_getinfo(control_connection_t *conn,
       goto done;
     }
     if (!ans) {
-      if (errmsg) /* use provided error message */
-        smartlist_add_strdup(unrecognized, errmsg);
-      else /* use default error message */
-        smartlist_add_asprintf(unrecognized, "Unrecognized key \"%s\"", q);
+      if (errmsg) {
+        /* use provided error message */
+        control_reply_add_str(unrecognized, 552, errmsg);
+      } else {
+        /* use default error message */
+        control_reply_add_printf(unrecognized, 552,
+                                 "Unrecognized key \"%s\"", q);
+      }
     } else {
-      smartlist_add_strdup(answers, q);
-      smartlist_add(answers, ans);
+      control_reply_add_one_kv(answers, 250, KV_RAW, q, ans);
     }
   } SMARTLIST_FOREACH_END(q);
 
-  if (smartlist_len(unrecognized)) {
-    /* control-spec section 2.3, mid-reply '-' or end of reply ' ' */
-    for (i=0; i < smartlist_len(unrecognized)-1; ++i)
-      control_write_midreply(conn, 552,
-                             (char *)smartlist_get(unrecognized, i));
+  control_reply_add_done(answers);
 
-    control_write_endreply(conn, 552, (char *)smartlist_get(unrecognized, i));
+  if (smartlist_len(unrecognized)) {
+    control_write_reply_lines(conn, unrecognized);
+    /* If there were any unrecognized queries, don't write real answers */
     goto done;
   }
 
-  for (i = 0; i < smartlist_len(answers); i += 2) {
-    char *k = smartlist_get(answers, i);
-    char *v = smartlist_get(answers, i+1);
-    if (!strchr(v, '\n') && !strchr(v, '\r')) {
-      control_printf_midreply(conn, 250, "%s=%s", k, v);
-    } else {
-      control_printf_datareply(conn, 250, "%s=", k);
-      control_write_data(conn, v);
-    }
-  }
-  send_control_done(conn);
+  control_write_reply_lines(conn, answers);
 
  done:
-  SMARTLIST_FOREACH(answers, char *, cp, tor_free(cp));
-  smartlist_free(answers);
-  SMARTLIST_FOREACH(unrecognized, char *, cp, tor_free(cp));
-  smartlist_free(unrecognized);
+  control_reply_free(answers);
+  control_reply_free(unrecognized);
 
   return 0;
 }
diff --git a/src/feature/control/control_proto.c b/src/feature/control/control_proto.c
index 5dec87491d..7d04fea6a7 100644
--- a/src/feature/control/control_proto.c
+++ b/src/feature/control/control_proto.c
@@ -22,6 +22,8 @@
 #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.
@@ -275,3 +277,158 @@ control_write_data(control_connection_t *conn, const char *data)
   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);
+}
diff --git a/src/feature/control/control_proto.h b/src/feature/control/control_proto.h
index 3182f3d415..cf7c000439 100644
--- a/src/feature/control/control_proto.h
+++ b/src/feature/control/control_proto.h
@@ -7,11 +7,56 @@
 /**
  * \file control_proto.h
  * \brief Header file for control_proto.c.
+ *
+ * See @ref replylines for details about the key-value abstraction for
+ * generating reply lines.
  **/
 
 #ifndef TOR_CONTROL_PROTO_H
 #define TOR_CONTROL_PROTO_H
 
+#include "lib/encoding/confline.h"
+
+/**
+ * @defgroup replylines Control reply lines
+ * @brief Key-value structures for control reply lines
+ *
+ * Control reply lines are config_line_t key-value structures with
+ * some additional information to help formatting, such as the numeric
+ * result code specified in the control protocol and flags affecting
+ * the way kvline_encode() formats the @a kvline.
+ *
+ * Generally, modules implementing control commands will work with
+ * smartlists of these structures, using functions like
+ * control_reply_add_str() for adding a reply line consisting of a
+ * single string, or control_reply_add_one_kv() and
+ * control_reply_append_kv() for composing a line containing one or
+ * more key-value pairs.
+ *
+ * @{
+ */
+/** @brief A reply line for the control protocol.
+ *
+ * This wraps config_line_t with some additional information that's
+ * useful when generating control reply lines.
+ */
+typedef struct control_reply_line_t {
+  int code;                     /**< numeric code */
+  int flags;                    /**< kvline encoding flags */
+  config_line_t *kvline;        /**< kvline */
+} control_reply_line_t;
+
+void control_reply_line_free_(control_reply_line_t *line);
+/**
+ * @brief Free and null a control_reply_line_t
+ *
+ * @param line pointer to control_reply_line_t to free
+ */
+#define control_reply_line_free(line)                   \
+  FREE_AND_NULL(control_reply_line_t,                   \
+                control_reply_line_free_, (line))
+/** @} */
+
 void connection_write_str_to_buf(const char *s, control_connection_t *conn);
 void connection_printf_to_buf(control_connection_t *conn,
                                      const char *format, ...)
@@ -45,4 +90,31 @@ void control_printf_datareply(control_connection_t *conn, int code,
   CHECK_PRINTF(3, 4);
 void control_write_data(control_connection_t *conn, const char *data);
 
+/** @addtogroup replylines
+ * @{
+ */
+void control_write_reply_line(control_connection_t *conn,
+                              const control_reply_line_t *line, bool lastone);
+void control_write_reply_lines(control_connection_t *conn, smartlist_t *lines);
+
+void control_reply_add_one_kv(smartlist_t *reply, int code, int flags,
+                              const char *key, const char *val);
+void control_reply_append_kv(smartlist_t *reply, const char *key,
+                             const char *val);
+void control_reply_add_str(smartlist_t *reply, int code, const char *s);
+void control_reply_add_printf(smartlist_t *reply, int code,
+                              const char *fmt, ...)
+  CHECK_PRINTF(3, 4);
+void control_reply_add_done(smartlist_t *reply);
+
+void control_reply_clear(smartlist_t *reply);
+void control_reply_free_(smartlist_t *reply);
+
+/** @brief Free and null a smartlist of control_reply_line_t.
+ *
+ * @param r pointer to smartlist_t of control_reply_line_t to free */
+#define control_reply_free(r) \
+  FREE_AND_NULL(smartlist_t, control_reply_free_, (r))
+/** @} */
+
 #endif /* !defined(TOR_CONTROL_PROTO_H) */