Parse prop171 options; refactor listener/port option code

Proposal 171 gives us a new syntax for parsing client port options.
You can now have as many FooPort options as you want (for Foo in
Socks, Trans, DNS, NATD), and they can have address:port arguments,
and you can specify the level of isolation on those ports.

Additionally, this patch refactors the client port parsing logic to
use a new type, port_cfg_t.  Previously, ports to be bound were
half-parsed in config.c, and later re-parsed in connection.c when
we're about to bind them.  Now, parsing a port means converting it
into a port_cfg_t, and binding it uses only a port_cfg_t, without
needing to parse the user-provided strings at all.

We should do a related refactoring on other port types.  For
control ports, that'll be easy enough.  For ORPort and DirPort,
we'll want to do this when we solve proposal 118 (letting servers
bind to and advertise multiple ports).

This implements tickets 3514 and 3515.

1 files changed, 368 insertions, 58 deletions

diff --git a/src/or/config.c b/src/or/config.c
index c6dd4673a..0774b2891 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -240,7 +240,7 @@ static config_var_t _option_vars[] = {
   VAR("DirServer",               LINELIST, DirServers, NULL),
   V(DisableAllSwap,              BOOL,     "0"),
   V(DisableIOCP,                 BOOL,     "1"),
-  V(DNSPort,                     PORT,     "0"),
+  V(DNSPort,                     LINELIST, NULL),
   V(DNSListenAddress,            LINELIST, NULL),
   V(DownloadExtraInfo,           BOOL,     "0"),
   V(EnforceDistinctSubnets,      BOOL,     "1"),
@@ -321,7 +321,7 @@ static config_var_t _option_vars[] = {
   V(NewCircuitPeriod,            INTERVAL, "30 seconds"),
   VAR("NamingAuthoritativeDirectory",BOOL, NamingAuthoritativeDir, "0"),
   V(NATDListenAddress,           LINELIST, NULL),
-  V(NATDPort,                    PORT,     "0"),
+  V(NATDPort,                    LINELIST, NULL),
   V(Nickname,                    STRING,   NULL),
   V(WarnUnsafeSocks,              BOOL,     "1"),
   OBSOLETE("NoPublish"),
@@ -374,7 +374,7 @@ static config_var_t _option_vars[] = {
   V(ShutdownWaitLength,          INTERVAL, "30 seconds"),
   V(SocksListenAddress,          LINELIST, NULL),
   V(SocksPolicy,                 LINELIST, NULL),
-  V(SocksPort,                   PORT,     "9050"),
+  V(SocksPort,                   LINELIST, NULL),
   V(SocksTimeout,                INTERVAL, "2 minutes"),
   OBSOLETE("StatusFetchPeriod"),
   V(StrictNodes,                 BOOL,     "0"),
@@ -385,7 +385,7 @@ static config_var_t _option_vars[] = {
   V(TrackHostExitsExpire,        INTERVAL, "30 minutes"),
   OBSOLETE("TrafficShaping"),
   V(TransListenAddress,          LINELIST, NULL),
-  V(TransPort,                   PORT,     "0"),
+  V(TransPort,                   LINELIST, NULL),
   V(TunnelDirConns,              BOOL,     "1"),
   V(UpdateBridgesFromAuthority,  BOOL,     "0"),
   V(UseBridges,                  BOOL,     "0"),
@@ -577,6 +577,8 @@ static int parse_client_transport_line(const char *line, int validate_only);
 static int parse_dir_server_line(const char *line,
                                  dirinfo_type_t required_type,
                                  int validate_only);
+static int parse_client_ports(const or_options_t *options, int validate_only,
+                              char **msg_out, int *n_ports_out);
 static int validate_data_directory(or_options_t *options);
 static int write_configuration_file(const char *fname,
                                     const or_options_t *options);
@@ -646,6 +648,8 @@ static or_state_t *global_state = NULL;
 static config_line_t *global_cmdline_options = NULL;
 /** Contents of most recently read DirPortFrontPage file. */
 static char *global_dirfrontpagecontents = NULL;
+/** List of port_cfg_t for client-level (SOCKS, DNS, Trans, NATD) ports. */
+static smartlist_t *configured_client_ports = NULL;
 
 /** Return the contents of our frontpage string, or NULL if not configured. */
 const char *
@@ -758,6 +762,13 @@ config_free_all(void)
   config_free_lines(global_cmdline_options);
   global_cmdline_options = NULL;
 
+  if (configured_client_ports) {
+    SMARTLIST_FOREACH(configured_client_ports,
+                      port_cfg_t *, p, tor_free(p));
+    smartlist_free(configured_client_ports);
+    configured_client_ports = NULL;
+  }
+
   tor_free(torrc_fname);
   tor_free(_version);
   tor_free(global_dirfrontpagecontents);
@@ -3027,6 +3038,7 @@ options_validate(or_options_t *old_options, or_options_t *options,
   int i;
   config_line_t *cl;
   const char *uname = get_uname();
+  int n_client_ports=0;
 #define REJECT(arg) \
   STMT_BEGIN *msg = tor_strdup(arg); return -1; STMT_END
 #define COMPLAIN(arg) STMT_BEGIN log(LOG_WARN, LD_CONFIG, arg); STMT_END
@@ -3050,57 +3062,8 @@ options_validate(or_options_t *old_options, or_options_t *options,
   if (options->DirPort == 0 && options->DirListenAddress != NULL)
     REJECT("DirPort must be defined if DirListenAddress is defined.");
 
-  if (options->DNSPort == 0 && options->DNSListenAddress != NULL)
-    REJECT("DNSPort must be defined if DNSListenAddress is defined.");
-
-  if (options->ControlPort == 0 && options->ControlListenAddress != NULL)
-    REJECT("ControlPort must be defined if ControlListenAddress is defined.");
-
-  if (options->TransPort == 0 && options->TransListenAddress != NULL)
-    REJECT("TransPort must be defined if TransListenAddress is defined.");
-
-  if (options->NATDPort == 0 && options->NATDListenAddress != NULL)
-    REJECT("NATDPort must be defined if NATDListenAddress is defined.");
-
-  /* Don't gripe about SocksPort 0 with SocksListenAddress set; a standard
-   * configuration does this. */
-
-  for (i = 0; i < 3; ++i) {
-    int is_socks = i==0;
-    int is_trans = i==1;
-    config_line_t *line, *opt, *old;
-    const char *tp;
-    if (is_socks) {
-      opt = options->SocksListenAddress;
-      old = old_options ? old_options->SocksListenAddress : NULL;
-      tp = "SOCKS proxy";
-    } else if (is_trans) {
-      opt = options->TransListenAddress;
-      old = old_options ? old_options->TransListenAddress : NULL;
-      tp = "transparent proxy";
-    } else {
-      opt = options->NATDListenAddress;
-      old = old_options ? old_options->NATDListenAddress : NULL;
-      tp = "natd proxy";
-    }
-
-    for (line = opt; line; line = line->next) {
-      char *address = NULL;
-      uint16_t port;
-      uint32_t addr;
-      if (parse_addr_port(LOG_WARN, line->value, &address, &addr, &port)<0)
-        continue; /* We'll warn about this later. */
-      if (!is_internal_IP(addr, 1) &&
-          (!old_options || !config_lines_eq(old, opt))) {
-        log_warn(LD_CONFIG,
-             "You specified a public address '%s' for a %s. Other "
-             "people on the Internet might find your computer and use it as "
-             "an open %s. Please don't allow this unless you have "
-             "a good reason.", address, tp, tp);
-      }
-      tor_free(address);
-    }
-  }
+  if (parse_client_ports(options, 1, msg, &n_client_ports) < 0)
+    return -1;
 
   if (validate_data_directory(options)<0)
     REJECT("Invalid DataDirectory");
@@ -3142,9 +3105,7 @@ options_validate(or_options_t *old_options, or_options_t *options,
     REJECT("Can't use a relative path to torrc when RunAsDaemon is set.");
 #endif
 
-  if (options->SocksPort == 0 && options->TransPort == 0 &&
-      options->NATDPort == 0 && options->ORPort == 0 &&
-      options->DNSPort == 0 && !options->RendConfigLines)
+  if (n_client_ports == 0 && options->ORPort == 0 && !options->RendConfigLines)
     log(LOG_WARN, LD_CONFIG,
         "SocksPort, TransPort, NATDPort, DNSPort, and ORPort are all "
         "undefined, and there aren't any hidden services configured.  "
@@ -4885,6 +4846,355 @@ parse_dir_server_line(const char *line, dirinfo_type_t required_type,
   return r;
 }
 
+/** Warn for every port in <b>ports</b> that is not on a loopback address. */
+static void
+warn_nonlocal_client_ports(const smartlist_t *ports, const char *portname)
+{
+  SMARTLIST_FOREACH_BEGIN(ports, const port_cfg_t *, port) {
+    if (!tor_addr_is_loopback(&port->addr)) {
+      log_warn(LD_CONFIG, "You specified a public address for %sPort. "
+               "Other people on the Internet might find your computer and "
+               "use it as an open proxy. Please don't allow this unless you "
+               "have a good reason.", portname);
+    }
+  } SMARTLIST_FOREACH_END(port);
+}
+
+#define CL_PORT_NO_OPTIONS    (1u<<0)
+#define CL_PORT_WARN_NONLOCAL (1u<<1)
+#define CL_PORT_ALLOW_EXTRA_LISTENADDR (1u<<2)
+
+/**
+ * Parse port configuration for a single client port type.
+ *
+ * Read entries of the "FooPort" type from the list <b>ports</b>, and
+ * entries of the "FooListenAddress" type from the list
+ * <b>listenaddrs</b>.  Two syntaxes are supported: a legacy syntax
+ * where FooPort is at most a single entry containing a port number and
+ * where FooListenAddress has any number of address:port combinations;
+ * and a new syntax where there are no FooListenAddress entries and
+ * where FooPort can have any number of entries of the format
+ * "[Address:][Port] IsolationOptions".
+ *
+ * In log messages, describe the port type as <b>portname</b>.
+ *
+ * If no address is specified, default to <b>defaultaddr</b>.  If no
+ * FooPort is given, default to defaultport (if 0, there is no default).
+ *
+ * If CL_PORT_NO_OPTIONS is set in <b>flags</b>, do not allow stream
+ * isolation options in the FooPort entries.
+ *
+ * If CL_PORT_WARN_NONLOCAL is set in <b>flags</b>, warn if any of the
+ * ports are not on a local address.
+ *
+ * Unless CL_PORT_ALLOW_EXTRA_LISTENADDR is set in <b>flags</b>, warn
+ * if FooListenAddress is set but FooPort is 0.
+ *
+ * On success, if <b>out</b> is given, add a new port_cfg_t entry to
+ * <b>out</b> for every port that the client should listen on.  Return 0
+ * on success, -1 on failure.
+ */
+static int
+parse_client_port_config(smartlist_t *out,
+                         const config_line_t *ports,
+                         const config_line_t *listenaddrs,
+                         const char *portname,
+                         int listener_type,
+                         const char *defaultaddr,
+                         int defaultport,
+                         unsigned flags)
+{
+  smartlist_t *elts;
+  int retval = -1;
+  const unsigned allow_client_options = !(flags & CL_PORT_NO_OPTIONS);
+  const unsigned warn_nonlocal = flags & CL_PORT_WARN_NONLOCAL;
+  const unsigned allow_spurious_listenaddr =
+    flags & CL_PORT_ALLOW_EXTRA_LISTENADDR;
+
+  /* FooListenAddress is deprecated; let's make it work like it used to work,
+   * though. */
+  if (listenaddrs) {
+    int mainport = defaultport;
+
+   if (ports && ports->next) {
+      log_warn(LD_CONFIG, "%sListenAddress can't be used when there are "
+               "multiple %sPort lines", portname, portname);
+      return -1;
+   } else if (ports) {
+     if (!strcmp(ports->value, "auto")) {
+       mainport = CFG_AUTO_PORT;
+     } else {
+       int ok;
+       mainport = (int)tor_parse_long(ports->value, 10, 0, 65535, &ok, NULL);
+       if (!ok) {
+         log_warn(LD_CONFIG, "%sListenAddress can only be used with a single "
+                  "%sPort with value \"auto\" or 65535.", portname, portname);
+         return -1;
+       }
+     }
+   }
+
+   if (mainport == 0) {
+     if (allow_spurious_listenaddr)
+       return 1;
+     log_warn(LD_CONFIG, "%sPort must be defined if %sListenAddress is used",
+              portname, portname);
+     return -1;
+   }
+
+   for (; listenaddrs; listenaddrs = listenaddrs->next) {
+     tor_addr_t addr;
+     uint16_t port = 0;
+     if (tor_addr_port_parse(listenaddrs->value, &addr, &port) < 0) {
+       log_warn(LD_CONFIG, "Unable to parse %sListenAddress '%s'",
+                portname, listenaddrs->value);
+       return -1;
+     }
+     if (out) {
+       port_cfg_t *cfg = tor_malloc_zero(sizeof(port_cfg_t));
+       cfg->type = listener_type;
+       cfg->port = port ? port : defaultport;
+       tor_addr_copy(&cfg->addr, &addr);
+       cfg->sessiongroup = -1;
+       cfg->isolate = ISO_DEFAULT;
+       smartlist_add(out, cfg);
+     }
+   }
+
+   if (warn_nonlocal && out)
+     warn_nonlocal_client_ports(out, portname);
+   return 0;
+  } /* end if (listenaddrs) */
+
+  /* No ListenAddress lines. If there's no FooPort, then maybe make a default
+   * one. */
+  if (! ports) {
+    if (defaultport && out) {
+       port_cfg_t *cfg = tor_malloc_zero(sizeof(port_cfg_t));
+       cfg->type = listener_type;
+       cfg->port = defaultport;
+       tor_addr_from_str(&cfg->addr, defaultaddr);
+       cfg->sessiongroup = -1;
+       cfg->isolate = ISO_DEFAULT;
+       smartlist_add(out, cfg);
+    }
+    return 0;
+  }
+
+  /* At last we can actually parse the FooPort lines.  The syntax is:
+   * [Addr:](Port|auto) [Options].*/
+  elts = smartlist_create();
+
+  for (; ports; ports = ports->next) {
+    tor_addr_t addr;
+    int port;
+    int sessiongroup = -1;
+    unsigned isolation = ISO_DEFAULT;
+
+    char *addrport;
+    uint16_t ptmp=0;
+    int ok;
+
+    smartlist_split_string(elts, ports->value, NULL,
+                           SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
+    if (smartlist_len(elts) == 0) {
+      log_warn(LD_CONFIG, "Invalid %sPort line with no value", portname);
+      goto err;
+    }
+
+    if (!allow_client_options && smartlist_len(elts) > 1) {
+      log_warn(LD_CONFIG, "Too many options on %sPort line", portname);
+      goto err;
+    }
+
+    /* Now parse the addr/port value */
+    addrport = smartlist_get(elts, 0);
+    if (!strcmp(addrport, "auto")) {
+      port = CFG_AUTO_PORT;
+      tor_addr_from_str(&addr, defaultaddr);
+    } else if (!strcasecmpend(addrport, ":auto")) {
+      char *addrtmp = tor_strndup(addrport, strlen(addrport)-5);
+      port = CFG_AUTO_PORT;
+      if (tor_addr_port_parse(addrtmp, &addr, &ptmp)<0 || ptmp) {
+        log_warn(LD_CONFIG, "Invalid address '%s' for %sPort",
+                 escaped(addrport), portname);
+        tor_free(addrtmp);
+        goto err;
+      }
+    } else if (tor_addr_port_parse(addrport, &addr, &ptmp) == 0) {
+      if (ptmp == 0) {
+        log_warn(LD_CONFIG, "%sPort line has address but no port", portname);
+        goto err;
+      }
+      port = ptmp;
+    } else {
+      port = (int) tor_parse_long(addrport, 10, 0, 65535, &ok, NULL);
+      if (!ok) {
+        log_warn(LD_CONFIG, "Couldn't parse address '%s' for %sPort",
+                 escaped(addrport), portname);
+        goto err;
+      }
+      tor_addr_from_str(&addr, defaultaddr);
+    }
+
+    /* Now parse the rest of the options, if any. */
+    SMARTLIST_FOREACH_BEGIN(elts, char *, elt) {
+      int no = 0, isoflag = 0;
+      const char *elt_orig = elt;
+      if (elt_sl_idx == 0)
+        continue; /* Skip addr:port */
+      if (!strcasecmpstart(elt, "SessionGroup=")) {
+        int group = tor_parse_long(elt+strlen("SessionGroup="),
+                                   10, 0, INT_MAX, &ok, NULL);
+        if (!ok) {
+          log_warn(LD_CONFIG, "Invalid %sPort option '%s'",
+                   portname, escaped(elt));
+          goto err;
+        }
+        if (sessiongroup >= 0) {
+          log_warn(LD_CONFIG, "Multiple SessionGroup options on %sPort",
+                   portname);
+          goto err;
+        }
+        sessiongroup = group;
+        continue;
+      }
+
+      if (!strcasecmpstart(elt, "No")) {
+        no = 1;
+        elt += 2;
+      }
+      if (!strcasecmpend(elt, "s"))
+        elt[strlen(elt)-1] = '\0'; /* kill plurals. */
+
+      if (!strcasecmp(elt, "IsolateDestPort")) {
+        isoflag = ISO_DESTPORT;
+      } else if (!strcasecmp(elt, "IsolateDestAddr")) {
+        isoflag = ISO_DESTADDR;
+      } else if (!strcasecmp(elt, "IsolateSOCKSAuth")) {
+        isoflag = ISO_SOCKSAUTH;
+      } else if (!strcasecmp(elt, "IsolateClientProtocol")) {
+        isoflag = ISO_CLIENTPROTO;
+      } else if (!strcasecmp(elt, "IsolateClientAddr")) {
+        isoflag = ISO_CLIENTADDR;
+      } else {
+        log_warn(LD_CONFIG, "Unrecognized %sPort option '%s'",
+                 portname, escaped(elt_orig));
+      }
+
+      if (no) {
+        isolation &= ~isoflag;
+      } else {
+        isolation |= isoflag;
+      }
+    } SMARTLIST_FOREACH_END(elt);
+
+    if (out) {
+      port_cfg_t *cfg = tor_malloc_zero(sizeof(port_cfg_t));
+      cfg->type = listener_type;
+      cfg->port = port;
+      tor_addr_copy(&cfg->addr, &addr);
+      cfg->sessiongroup = sessiongroup;
+      cfg->isolate = isolation;
+      smartlist_add(out, cfg);
+    }
+    SMARTLIST_FOREACH(elts, char *, cp, tor_free(cp));
+    smartlist_clear(elts);
+  }
+
+  if (warn_nonlocal && out)
+    warn_nonlocal_client_ports(out, portname);
+
+  retval = 0;
+ err:
+  SMARTLIST_FOREACH(elts, char *, cp, tor_free(cp));
+  smartlist_free(elts);
+  return retval;
+}
+
+/** Parse all client port types (Socks, DNS, Trans, NATD) from
+ * <b>options</b>. On success, set *<b>n_ports_out</b> to the number of
+ * ports that are listed and return 0.  On failure, set *<b>msg</b> to a
+ * description of the problem and return -1.
+ *
+ * If <b>validate_only</b> is false, set configured_client_ports to the
+ * new list of ports parsed from <b>options</b>.
+ **/
+static int
+parse_client_ports(const or_options_t *options, int validate_only,
+                   char **msg, int *n_ports_out)
+{
+  smartlist_t *ports;
+  int retval = -1;
+
+  ports = smartlist_create();
+
+  *n_ports_out = 0;
+
+  if (parse_client_port_config(ports,
+             options->SocksPort, options->SocksListenAddress,
+             "Socks", CONN_TYPE_AP_LISTENER,
+             "127.0.0.1", 9050,
+             CL_PORT_WARN_NONLOCAL|CL_PORT_ALLOW_EXTRA_LISTENADDR) < 0) {
+    *msg = tor_strdup("Invalid SocksPort/SocksListenAddress configuration");
+    goto err;
+  }
+  if (parse_client_port_config(ports,
+                               options->DNSPort, options->DNSListenAddress,
+                               "DNS", CONN_TYPE_AP_DNS_LISTENER,
+                               "127.0.0.1", 0,
+                               CL_PORT_WARN_NONLOCAL) < 0) {
+    *msg = tor_strdup("Invalid DNSPort/DNSListenAddress configuration");
+    goto err;
+  }
+  if (parse_client_port_config(ports,
+                               options->TransPort, options->TransListenAddress,
+                               "Trans", CONN_TYPE_AP_TRANS_LISTENER,
+                               "127.0.0.1", 0,
+                               CL_PORT_WARN_NONLOCAL) < 0) {
+    *msg = tor_strdup("Invalid TransPort/TransListenAddress configuration");
+    goto err;
+  }
+  if (parse_client_port_config(ports,
+                               options->NATDPort, options->NATDListenAddress,
+                               "NATD", CONN_TYPE_AP_NATD_LISTENER,
+                               "127.0.0.1", 0,
+                               CL_PORT_WARN_NONLOCAL) < 0) {
+    *msg = tor_strdup("Invalid NatdPort/NatdListenAddress configuration");
+    goto err;
+  }
+
+  *n_ports_out = smartlist_len(ports);
+
+  if (!validate_only) {
+    if (configured_client_ports) {
+      SMARTLIST_FOREACH(configured_client_ports,
+                        port_cfg_t *, p, tor_free(p));
+      smartlist_free(configured_client_ports);
+    }
+    configured_client_ports = ports;
+    ports = NULL; /* prevent free below. */
+  }
+
+  retval = 0;
+ err:
+  if (ports) {
+    SMARTLIST_FOREACH(ports, port_cfg_t *, p, tor_free(p));
+    smartlist_free(ports);
+  }
+  return retval;
+}
+
+/** Return a list of port_cfg_t for client ports parsed from the
+ * options. */
+const smartlist_t *
+get_configured_client_ports(void)
+{
+  if (!configured_client_ports)
+    configured_client_ports = smartlist_create();
+  return configured_client_ports;
+}
+
 /** Adjust the value of options->DataDirectory, or fill it in if it's
  * absent. Return 0 on success, -1 on failure. */
 static int