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- /* Copyright (c) 2001, Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file dispatch_new.c
- * \brief Code to construct a dispatch_t from a dispatch_cfg_t.
- **/
- #define DISPATCH_PRIVATE
- #include "orconfig.h"
- #include "lib/dispatch/dispatch.h"
- #include "lib/dispatch/dispatch_st.h"
- #include "lib/dispatch/dispatch_cfg.h"
- #include "lib/dispatch/dispatch_cfg_st.h"
- #include "lib/cc/ctassert.h"
- #include "lib/intmath/cmp.h"
- #include "lib/malloc/malloc.h"
- #include "lib/log/util_bug.h"
- #include <string.h>
- /** Given a smartlist full of (possibly NULL) pointers to uint16_t values,
- * return the largest value, or dflt if the list is empty. */
- static int
- max_in_sl(const smartlist_t *sl, int dflt)
- {
- uint16_t *maxptr = NULL;
- SMARTLIST_FOREACH_BEGIN(sl, uint16_t *, u) {
- if (!maxptr)
- maxptr = u;
- else if (*u > *maxptr)
- maxptr = u;
- } SMARTLIST_FOREACH_END(u);
- return maxptr ? *maxptr : dflt;
- }
- /* The above function is only safe to call if we are sure that channel_id_t
- * and msg_type_id_t are really uint16_t. They should be so defined in
- * msgtypes.h, but let's be extra cautious.
- */
- CTASSERT(sizeof(uint16_t) == sizeof(msg_type_id_t));
- CTASSERT(sizeof(uint16_t) == sizeof(channel_id_t));
- /** Helper: Format an unformattable message auxiliary data item: just return a
- * copy of the string <>. */
- static char *
- type_fmt_nop(msg_aux_data_t arg)
- {
- (void)arg;
- return tor_strdup("<>");
- }
- /** Helper: Free an unfreeable message auxiliary data item: do nothing. */
- static void
- type_free_nop(msg_aux_data_t arg)
- {
- (void)arg;
- }
- /** Type functions to use when no type functions are provided. */
- static dispatch_typefns_t nop_typefns = {
- .free_fn = type_free_nop,
- .fmt_fn = type_fmt_nop
- };
- /**
- * Alert function to use when none is configured: do nothing.
- **/
- static void
- alert_fn_nop(dispatch_t *d, channel_id_t ch, void *arg)
- {
- (void)d;
- (void)ch;
- (void)arg;
- }
- /**
- * Given a list of recvfn_t, create and return a new dtbl_entry_t mapping
- * to each of those functions.
- **/
- static dtbl_entry_t *
- dtbl_entry_from_lst(smartlist_t *receivers)
- {
- if (!receivers)
- return NULL;
- size_t n_recv = smartlist_len(receivers);
- dtbl_entry_t *ent;
- ent = tor_malloc_zero(offsetof(dtbl_entry_t, rcv) +
- sizeof(dispatch_rcv_t) * n_recv);
- ent->n_fns = n_recv;
- SMARTLIST_FOREACH_BEGIN(receivers, const dispatch_rcv_t *, rcv) {
- memcpy(&ent->rcv[rcv_sl_idx], rcv, sizeof(*rcv));
- if (rcv->enabled) {
- ++ent->n_enabled;
- }
- } SMARTLIST_FOREACH_END(rcv);
- return ent;
- }
- /** Create and return a new dispatcher from a given dispatch_cfg_t. */
- dispatch_t *
- dispatch_new(const dispatch_cfg_t *cfg)
- {
- dispatch_t *d = tor_malloc_zero(sizeof(dispatch_t));
- /* Any message that has a type or a receiver counts towards our messages */
- const size_t n_msgs = MAX(smartlist_len(cfg->type_by_msg),
- smartlist_len(cfg->recv_by_msg)) + 1;
- /* Any channel that any message has counts towards the number of channels. */
- const size_t n_chans = (size_t) MAX(1, max_in_sl(cfg->chan_by_msg,0)) + 1;
- /* Any type that a message has, or that has functions, counts towards
- * the number of types. */
- const size_t n_types = (size_t) MAX(max_in_sl(cfg->type_by_msg,0),
- smartlist_len(cfg->fns_by_type)) + 1;
- d->n_msgs = n_msgs;
- d->n_queues = n_chans;
- d->n_types = n_types;
- /* Initialize the array of type-functions. */
- d->typefns = tor_calloc(n_types, sizeof(dispatch_typefns_t));
- for (size_t i = 0; i < n_types; ++i) {
- /* Default to no-op for everything... */
- memcpy(&d->typefns[i], &nop_typefns, sizeof(dispatch_typefns_t));
- }
- SMARTLIST_FOREACH_BEGIN(cfg->fns_by_type, dispatch_typefns_t *, fns) {
- /* Set the functions if they are provided. */
- if (fns) {
- if (fns->free_fn)
- d->typefns[fns_sl_idx].free_fn = fns->free_fn;
- if (fns->fmt_fn)
- d->typefns[fns_sl_idx].fmt_fn = fns->fmt_fn;
- }
- } SMARTLIST_FOREACH_END(fns);
- /* Initialize the message queues: one for each channel. */
- d->queues = tor_calloc(d->n_queues, sizeof(dqueue_t));
- for (size_t i = 0; i < d->n_queues; ++i) {
- TOR_SIMPLEQ_INIT(&d->queues[i].queue);
- d->queues[i].alert_fn = alert_fn_nop;
- }
- /* Build the dispatch tables mapping message IDs to receivers. */
- d->table = tor_calloc(d->n_msgs, sizeof(dtbl_entry_t *));
- SMARTLIST_FOREACH_BEGIN(cfg->recv_by_msg, smartlist_t *, rcv) {
- d->table[rcv_sl_idx] = dtbl_entry_from_lst(rcv);
- } SMARTLIST_FOREACH_END(rcv);
- /* Fill in the empty entries in the dispatch tables:
- * types and channels for each message. */
- SMARTLIST_FOREACH_BEGIN(cfg->type_by_msg, msg_type_id_t *, type) {
- if (d->table[type_sl_idx])
- d->table[type_sl_idx]->type = *type;
- } SMARTLIST_FOREACH_END(type);
- SMARTLIST_FOREACH_BEGIN(cfg->chan_by_msg, channel_id_t *, chan) {
- if (d->table[chan_sl_idx])
- d->table[chan_sl_idx]->channel = *chan;
- } SMARTLIST_FOREACH_END(chan);
- return d;
- }
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