r15422@catbus: nickm | 2007-09-27 16:42:35 -0400

 Use descriptor annotations to record the source, download t time, and purpose of every descriptor we add to the store.  The remaining to-do item is to stop setting do_not_cache on bridges.


svn:r11680

ChangeLog

@@ -8,6 +8,9 @@ Changes in version 0.2.0.8-alpha - 2007-??-??
       cached-routers.  Initialize cached-descriptors from cached-routers
       if the old format is around.  The new format allows us to store
       annotations along with descriptors.
+    - Use annotations to record the time we received each descriptor.
+    - Use annotations to record the source for each descriptor.
+    - Use annotations to record the purpose of each descriptor.
 
   o Minor bugfixes (controller):
     - When sending a status event to the controller telling it that an

doc/TODO

@@ -132,7 +132,7 @@ R     - drop 'authority' queries if they're to our own identity key; accept
       o be more robust to bridges being marked as down and leaving us
         stranded without any known "running" bridges.
 N     . Cache for bridge descriptors
-        . Annotated router store
+        o Annotated router store
           o Accept annotations before routers
           o Preserve and ignore unexpected annotations
           o Mechanism to add annotations when we first add a descriptor
@@ -141,11 +141,15 @@ N     . Cache for bridge descriptors
           o Name the router store something different: cached-descriptors?
             o But load from cached-routers if no cached-descriptors is
               found.
-            - Document this.
-        - Use annotations to denote router purpose
-          - Learn purpose from annotations
-          - Set annotations based on purpose
-          - Preserve routers with unrecognized purpose.
+            o Document this.
+          o Add a few example annotations to make sure this works: source
+            and downloaded/uploaded-at seem like a good start
+            - Drop this later as needed.
+        o Use annotations to denote router purpose
+          o Learn purpose from annotations
+          o Set annotations based on purpose
+          o Preserve routers with unrecognized purpose.
+R       - Stop setting the do-not-cache flag based on purpose.
     - Bridges operators (rudimentary version)
       - Ability to act as dir cache without a dir port.
       o Bridges publish to bridge authorities

doc/tor.1.in

@@ -1169,8 +1169,12 @@ The tor process stores keys and other data here.
 The most recently downloaded network status document for each authority.  Each file holds one such document; the filenames are the hexadecimal identity key fingerprints of the directory authorities.
 .LP
 .TP
+.B \fIDataDirectory\fB/cached-descriptors\fR and \fBcached-descriptors.new\fR
+These files hold downloaded router statuses.  Some routers may appear more than once; if so, the most recently published descriptor is used.    Lines beginning with @-signs are annotations that contain more information about a given router.  The ".new" file is an append-only journal; when it gets too large, all entries are merged into a new cached-routers file.
+.LP
+.TP
 .B \fIDataDirectory\fB/cached-routers\fR and \fBcached-routers.new\fR
-These files hold downloaded router statuses.  Some routers may appear more than once; if so, the most recently published descriptor is used.  The ".new" file is an append-only journal; when it gets too large, all entries are merged into a new cached-routers file.
+Obsolete versions of cached-descriptors and cached-descriptors.new.  When Tor can't find the newer files, it looks here instead.
 .LP
 .TP
 .B \fIDataDirectory\fP/state

src/or/control.c

@@ -1884,12 +1884,18 @@ get_purpose(char **string, int for_circuits, uint8_t *purpose)
   if (!strcmpstart(*string, "purpose="))
     *string += strlen("purpose=");
 
+  if (!for_circuits) {
+    int r = router_purpose_from_string(*string);
+    if (r == ROUTER_PURPOSE_UNKNOWN)
+      return -1;
+    *purpose = r;
+    return 0;
+  }
+
   if (!strcmp(*string, "general"))
-    *purpose = for_circuits ? CIRCUIT_PURPOSE_C_GENERAL :
-                              ROUTER_PURPOSE_GENERAL;
+    *purpose = CIRCUIT_PURPOSE_C_GENERAL;
   else if (!strcmp(*string, "controller"))
-    *purpose = for_circuits ? CIRCUIT_PURPOSE_CONTROLLER :
-                              ROUTER_PURPOSE_CONTROLLER;
+    *purpose = CIRCUIT_PURPOSE_CONTROLLER;
   else { /* not a recognized purpose */
     return -1;
   }

src/or/directory.c

@@ -1066,6 +1066,31 @@ body_is_plausible(const char *body, size_t len, int purpose)
   }
 }
 
+/** DOCDOC */
+static void
+load_downloaded_routers(const char *body, smartlist_t *which,
+                        int descriptor_digests,
+                        int router_purpose,
+                        const char *source)
+{
+  char buf[256];
+  char time_buf[ISO_TIME_LEN+1];
+  int general = router_purpose == ROUTER_PURPOSE_GENERAL;
+  format_iso_time(time_buf, time(NULL));
+
+  if (tor_snprintf(buf, sizeof(buf),
+                   "@downloaded-at %s\n"
+                   "@source %s\n"
+                   "%s%s%s", time_buf, escaped(source),
+                   !general ? "@purpose " : "",
+                   !general ? router_purpose_to_string(router_purpose) : "",
+                   !general ? "\n" : "")<0)
+    return;
+
+  router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
+                                  descriptor_digests, buf);
+}
+
 /** We are a client, and we've finished reading the server's
  * response. Parse and it and act appropriately.
  *
@@ -1460,8 +1485,11 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
         router_load_extrainfo_from_string(body, NULL, SAVED_NOWHERE, which,
                                           descriptor_digests);
       } else {
-        router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
-                               descriptor_digests, conn->router_purpose);
+        //router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
+        //                       descriptor_digests, conn->router_purpose);
+        load_downloaded_routers(body, which, descriptor_digests,
+                                conn->router_purpose,
+                                conn->_base.address);
         directory_info_has_arrived(now, 0);
       }
     }
@@ -2414,7 +2442,8 @@ directory_handle_command_post(dir_connection_t *conn, const char *headers,
     const char *msg = NULL;
     uint8_t purpose = authdir_mode_bridge(options) ?
                       ROUTER_PURPOSE_BRIDGE : ROUTER_PURPOSE_GENERAL;
-    int r = dirserv_add_multiple_descriptors(body, purpose, &msg);
+    int r = dirserv_add_multiple_descriptors(body, purpose,
+                                             conn->_base.address, &msg);
     tor_assert(msg);
     if (r > 0)
       dirserv_get_directory(); /* rebuild and write to disk */

src/or/dirserv.c

@@ -524,6 +524,7 @@ authdir_wants_to_reject_router(routerinfo_t *ri, const char **msg,
  * returns the most severe error that occurred for any one of them. */
 int
 dirserv_add_multiple_descriptors(const char *desc, uint8_t purpose,
+                                 const char *source,
                                  const char **msg)
 {
   int r=100; /* higher than any actual return value. */
@@ -532,12 +533,28 @@ dirserv_add_multiple_descriptors(const char *desc, uint8_t purpose,
   smartlist_t *list;
   const char *s;
   int n_parsed = 0;
+  time_t now = time(NULL);
+  char annotation_buf[256];
+  char time_buf[ISO_TIME_LEN+1];
+  int general = purpose == ROUTER_PURPOSE_GENERAL;
   tor_assert(msg);
 
+  format_iso_time(time_buf, now);
+  if (tor_snprintf(annotation_buf, sizeof(annotation_buf),
+                   "@uploaded-at %s\n"
+                   "@source %s\n"
+                   "%s%s%s", time_buf, escaped(source),
+                   !general ? "@purpose " : "",
+                   !general ? router_purpose_to_string(purpose) : "",
+                   !general ? "\n" : "")<0) {
+    *msg = "Couldn't format annotations";
+    return -1;
+  }
+
   s = desc;
   list = smartlist_create();
   if (!router_parse_list_from_string(&s, NULL, list, SAVED_NOWHERE, 0, 0,
-                                     NULL)) {
+                                     annotation_buf)) {
     SMARTLIST_FOREACH(list, routerinfo_t *, ri, {
         msg_out = NULL;
 
@@ -548,8 +565,8 @@ dirserv_add_multiple_descriptors(const char *desc, uint8_t purpose,
          * router_load_single_router()? Lastly, does extrainfo_t want
          * a purpose field too, or can we just piggyback off the one
          * in routerinfo_t? */
-        ri->purpose = purpose;
-        if (purpose != ROUTER_PURPOSE_GENERAL)
+        tor_assert(ri->purpose == purpose);
+        if (purpose != ROUTER_PURPOSE_GENERAL) /*XXXXX020 wrong. */
           ri->cache_info.do_not_cache = 1;
 
         r_tmp = dirserv_add_descriptor(ri, &msg_out);
@@ -603,6 +620,9 @@ dirserv_add_multiple_descriptors(const char *desc, uint8_t purpose,
  *  1 if well-formed and accepted but origin should hear *msg;
  *  0 if well-formed but redundant with one we already have;
  * -1 if it looks vaguely like a router descriptor but rejected;
+ *
+ * This function is only called when fresh descriptors are posted, not when
+ * we re-load the cache.
  */
 int
 dirserv_add_descriptor(routerinfo_t *ri, const char **msg)

src/or/or.h

@@ -1167,6 +1167,8 @@ typedef struct {
 #define ROUTER_PURPOSE_CONTROLLER 1
 /** Tor should use this router only for bridge positions in circuits. */
 #define ROUTER_PURPOSE_BRIDGE 2
+/** DOCDOC */
+#define ROUTER_PURPOSE_UNKNOWN 255
 
   uint8_t purpose; /** What positions in a circuit is this router good for? */
 
@@ -2779,6 +2781,7 @@ int dirserv_load_fingerprint_file(void);
 void dirserv_free_fingerprint_list(void);
 const char *dirserv_get_nickname_by_digest(const char *digest);
 int dirserv_add_multiple_descriptors(const char *desc, uint8_t purpose,
+                                     const char *source,
                                      const char **msg);
 int dirserv_add_descriptor(routerinfo_t *ri, const char **msg);
 int getinfo_helper_dirserv_unregistered(control_connection_t *conn,
@@ -3357,6 +3360,9 @@ void router_reset_warnings(void);
 void router_reset_reachability(void);
 void router_free_all(void);
 
+const char *router_purpose_to_string(uint8_t p);
+uint8_t router_purpose_from_string(const char *s);
+
 #ifdef ROUTER_PRIVATE
 /* Used only by router.c and test.c */
 void get_platform_str(char *platform, size_t len);
@@ -3480,7 +3486,7 @@ void router_load_routers_from_string(const char *s, const char *eos,
                                      saved_location_t saved_location,
                                      smartlist_t *requested_fingerprints,
                                      int descriptor_digests,
-                                     uint8_t purpose);
+                                     const char *prepend_annotations);
 void router_load_extrainfo_from_string(const char *s, const char *eos,
                                        saved_location_t saved_location,
                                        smartlist_t *requested_fps,

src/or/router.c

@@ -1773,6 +1773,35 @@ router_reset_warnings(void)
   }
 }
 
+/** DOCDOC */
+const char *
+router_purpose_to_string(uint8_t p)
+{
+  switch (p)
+    {
+    case ROUTER_PURPOSE_GENERAL: return "general";
+    case ROUTER_PURPOSE_BRIDGE: return "bridge";
+    case ROUTER_PURPOSE_CONTROLLER: return "controller";
+    default:
+      tor_assert(0);
+    }
+  return NULL;
+}
+
+/** DOCDOC */
+uint8_t
+router_purpose_from_string(const char *s)
+{
+  if (!strcmp(s, "general"))
+    return ROUTER_PURPOSE_GENERAL;
+  else if (!strcmp(s, "bridge"))
+    return ROUTER_PURPOSE_BRIDGE;
+  else if (!strcmp(s, "controller"))
+    return ROUTER_PURPOSE_CONTROLLER;
+  else
+    return ROUTER_PURPOSE_UNKNOWN;
+}
+
 /** Release all static resources held in router.c */
 void
 router_free_all(void)

src/or/routerlist.c

@@ -675,7 +675,7 @@ router_rebuild_store(int force, desc_store_t *store)
         tor_free(sd->signed_descriptor_body); // sets it to null
         sd->saved_offset = offset;
       }
-      offset += sd->signed_descriptor_len;
+      offset += sd->signed_descriptor_len + sd->annotations_len;
       signed_descriptor_get_body(sd); /* reconstruct and assert */
     });
 
@@ -743,8 +743,7 @@ router_reload_router_list_impl(desc_store_t *store)
     else
       router_load_routers_from_string(store->mmap->data,
                                       store->mmap->data+store->mmap->size,
-                                      SAVED_IN_CACHE, NULL, 0,
-                                      ROUTER_PURPOSE_GENERAL);
+                                      SAVED_IN_CACHE, NULL, 0, NULL);
   }
 
   tor_snprintf(fname, fname_len, "%s"PATH_SEPARATOR"%s.new",
@@ -762,7 +761,7 @@ router_reload_router_list_impl(desc_store_t *store)
                                         NULL, 0);
     else
       router_load_routers_from_string(contents, NULL, SAVED_IN_JOURNAL,
-                                      NULL, 0, ROUTER_PURPOSE_GENERAL);
+                                      NULL, 0, NULL);
     store->journal_len = (size_t) st.st_size;
     tor_free(contents);
   }
@@ -2010,11 +2009,13 @@ signed_descriptor_get_body_impl(signed_descriptor_t *desc,
       (with_annotations ? 0 : desc->annotations_len);
 
   tor_assert(r);
-  if (memcmp("router ", r, 7) && memcmp("extra-info ", r, 11)) {
-    log_err(LD_DIR, "descriptor at %p begins with unexpected string %s",
-            desc, tor_strndup(r, 64));
+  if (!with_annotations) {
+    if (memcmp("router ", r, 7) && memcmp("extra-info ", r, 11)) {
+      log_err(LD_DIR, "descriptor at %p begins with unexpected string %s",
+              desc, tor_strndup(r, 64));
+    }
+    tor_assert(!memcmp("router ", r, 7) || !memcmp("extra-info ", r, 11));
   }
-  tor_assert(!memcmp("router ", r, 7) || !memcmp("extra-info ", r, 11));
 
   return r;
 }
@@ -3116,15 +3117,20 @@ router_load_single_router(const char *s, uint8_t purpose, const char **msg)
   routerinfo_t *ri;
   int r;
   smartlist_t *lst;
+  char annotation_buf[256];
   tor_assert(msg);
   *msg = NULL;
 
-  if (!(ri = router_parse_entry_from_string(s, NULL, 1, 0, NULL))) {
+  tor_snprintf(annotation_buf, sizeof(annotation_buf),
+               "@source controller\n"
+               "@purpose %s\n", router_purpose_to_string(purpose));
+
+  if (!(ri = router_parse_entry_from_string(s, NULL, 1, 0, annotation_buf))) {
     log_warn(LD_DIR, "Error parsing router descriptor; dropping.");
     *msg = "Couldn't parse router descriptor.";
     return -1;
   }
-  ri->purpose = purpose;
+  tor_assert(ri->purpose == purpose);
   if (ri->purpose != ROUTER_PURPOSE_GENERAL)
     ri->cache_info.do_not_cache = 1;
   if (router_is_me(ri)) {
@@ -3171,7 +3177,7 @@ router_load_routers_from_string(const char *s, const char *eos,
                                 saved_location_t saved_location,
                                 smartlist_t *requested_fingerprints,
                                 int descriptor_digests,
-                                uint8_t purpose)
+                                const char *prepend_annotations)
 {
   smartlist_t *routers = smartlist_create(), *changed = smartlist_create();
   char fp[HEX_DIGEST_LEN+1];
@@ -3180,7 +3186,7 @@ router_load_routers_from_string(const char *s, const char *eos,
   int allow_annotations = (saved_location != SAVED_NOWHERE);
 
   router_parse_list_from_string(&s, eos, routers, saved_location, 0,
-                                allow_annotations, NULL);
+                                allow_annotations, prepend_annotations);
 
   routers_update_status_from_networkstatus(routers, !from_cache);
 
@@ -3208,8 +3214,7 @@ router_load_routers_from_string(const char *s, const char *eos,
       }
     }
 
-    ri->purpose = purpose;
-    if (purpose != ROUTER_PURPOSE_GENERAL)
+    if (ri->purpose != ROUTER_PURPOSE_GENERAL) /* XXXX020 wrong. */
       ri->cache_info.do_not_cache = 1;
 
     if (router_add_to_routerlist(ri, &msg, from_cache, !from_cache) >= 0) {

src/or/routerparse.c

@@ -1015,6 +1015,7 @@ router_parse_entry_from_string(const char *s, const char *end,
   directory_token_t *tok;
   struct in_addr in;
   const char *start_of_annotations, *cp;
+  size_t prepend_len = prepend_annotations ? strlen(prepend_annotations) : 0;
 
   tor_assert(!allow_annotations || !prepend_annotations);
 
@@ -1068,17 +1069,12 @@ router_parse_entry_from_string(const char *s, const char *end,
     goto err;
   }
 
-  tok = smartlist_get(tokens,0);
-  if (tok->tp != K_ROUTER) {
-    log_warn(LD_DIR,"Entry does not start with \"router\"");
-    goto err;
-  }
+  tok = find_first_by_keyword(tokens, K_ROUTER);
   tor_assert(tok->n_args >= 5);
 
   router = tor_malloc_zero(sizeof(routerinfo_t));
   router->routerlist_index = -1;
-  router->cache_info.annotations_len = s-start_of_annotations +
-    (prepend_annotations ? strlen(prepend_annotations) : 0) ;
+  router->cache_info.annotations_len = s-start_of_annotations + prepend_len;
   router->cache_info.signed_descriptor_len = end-s;
   if (cache_copy) {
     size_t len = router->cache_info.signed_descriptor_len +
@@ -1086,11 +1082,12 @@ router_parse_entry_from_string(const char *s, const char *end,
     char *cp =
       router->cache_info.signed_descriptor_body = tor_malloc(len+1);
     if (prepend_annotations) {
-      strlcpy(cp, prepend_annotations, len+1);
-      cp += strlen(prepend_annotations);
+      memcpy(cp, prepend_annotations, prepend_len);
+      cp += prepend_len;
     }
-    memcpy(cp, s, end-s);
-    cp[len] = '\0';
+    memcpy(cp, start_of_annotations, end-start_of_annotations);
+    router->cache_info.signed_descriptor_body[len] = '\0';
+    tor_assert(strlen(router->cache_info.signed_descriptor_body) == len);
   }
   memcpy(router->cache_info.signed_descriptor_digest, digest, DIGEST_LEN);
 
@@ -1116,8 +1113,6 @@ router_parse_entry_from_string(const char *s, const char *end,
   router->bandwidthrate =
     tor_parse_long(tok->args[0],10,0,INT_MAX,NULL,NULL);
 
-  /* Set purpose XXXX020 NM NM*/
-
   if (!router->bandwidthrate) {
     log_warn(LD_DIR, "bandwidthrate %s unreadable or 0. Failing.",
              escaped(tok->args[0]));
@@ -1129,6 +1124,13 @@ router_parse_entry_from_string(const char *s, const char *end,
     tor_parse_long(tok->args[2],10,0,INT_MAX,NULL,NULL);
   /* XXXX020 we don't error-check these values? -RD */
 
+  if ((tok = find_first_by_keyword(tokens, A_PURPOSE))) {
+    tor_assert(tok->n_args);
+    router->purpose = router_purpose_from_string(tok->args[0]);
+  } else {
+    router->purpose = ROUTER_PURPOSE_GENERAL;
+  }
+
   if ((tok = find_first_by_keyword(tokens, K_UPTIME))) {
     tor_assert(tok->n_args >= 1);
     router->uptime = tor_parse_long(tok->args[0],10,0,LONG_MAX,NULL,NULL);