src/lib/pubsub/pubsub_publish.c

   1 /* Copyright (c) 2001, Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2021, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 /**
   8  * @file pubsub_publish.c
   9  * @brief Header for functions to publish using a pub_binding_t.
  10  **/
  11
  12 #define PUBSUB_PRIVATE
  13 #define DISPATCH_PRIVATE
  14 #include "orconfig.h"
  15
  16 #include "lib/dispatch/dispatch.h"
  17 #include "lib/dispatch/dispatch_st.h"
  18
  19 #include "lib/pubsub/pub_binding_st.h"
  20 #include "lib/pubsub/pubsub_publish.h"
  21
  22 #include "lib/malloc/malloc.h"
  23 #include "lib/log/util_bug.h"
  24
  25 #include <string.h>
  26
  27 /**
  28  * Publish a message from the publication binding <b>pub</b> using the
  29  * auxiliary data <b>auxdata</b>.
  30  *
  31  * Return 0 on success, -1 on failure.
  32  **/
  33 int
  34 pubsub_pub_(const pub_binding_t *pub, msg_aux_data_t auxdata)
  35 {
  36   dispatch_t *d = pub->dispatch_ptr;
  37   if (BUG(! d)) {
  38     /* Tried to publish a message before the dispatcher was configured. */
  39     /* (Without a dispatcher, we don't know how to free auxdata.) */
  40     return -1;
  41   }
  42
  43   if (BUG(pub->msg_template.type >= d->n_types)) {
  44     /* The type associated with this message is not known to the dispatcher. */
  45     /* (Without a correct type, we don't know how to free auxdata.) */
  46     return -1;
  47   }
  48
  49   if (BUG(pub->msg_template.msg >= d->n_msgs) ||
  50       BUG(pub->msg_template.channel >= d->n_queues)) {
  51     /* The message ID or channel ID was out of bounds. */
  52     // LCOV_EXCL_START
  53     d->typefns[pub->msg_template.type].free_fn(auxdata);
  54     return -1;
  55     // LCOV_EXCL_STOP
  56   }
  57
  58   if (! d->table[pub->msg_template.msg]) {
  59     /* Fast path: nobody wants this data. */
  60
  61     // XXXX Faster path: we could store this in the pub_binding_t.
  62     d->typefns[pub->msg_template.type].free_fn(auxdata);
  63     return 0;
  64   }
  65
  66   /* Construct the message object */
  67   msg_t *m = tor_malloc(sizeof(msg_t));
  68   memcpy(m, &pub->msg_template, sizeof(msg_t));
  69   m->aux_data__ = auxdata;
  70
  71   return dispatch_send_msg_unchecked(d, m);
  72 }