diff options
Diffstat (limited to 'src/or/channel.c')
| -rw-r--r-- | src/or/channel.c | 52 |
1 files changed, 43 insertions, 9 deletions
diff --git a/src/or/channel.c b/src/or/channel.c index 21522a5303..5f69a0864b 100644 --- a/src/or/channel.c +++ b/src/or/channel.c @@ -1,9 +1,13 @@ -/* * Copyright (c) 2012-2015, The Tor Project, Inc. */ +/* * Copyright (c) 2012-2016, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file channel.c - * \brief OR-to-OR channel abstraction layer + * + * \brief OR/OP-to-OR channel abstraction layer. A channel's job is to + * transfer cells from Tor instance to Tor instance. + * Currently, there is only one implementation of the channel abstraction: in + * channeltls.c. **/ /* @@ -127,13 +131,13 @@ typedef struct channel_idmap_entry_s { TOR_LIST_HEAD(channel_list_s, channel_s) channel_list; } channel_idmap_entry_t; -static INLINE unsigned +static inline unsigned channel_idmap_hash(const channel_idmap_entry_t *ent) { return (unsigned) siphash24g(ent->digest, DIGEST_LEN); } -static INLINE int +static inline int channel_idmap_eq(const channel_idmap_entry_t *a, const channel_idmap_entry_t *b) { @@ -2652,6 +2656,11 @@ channel_process_cells(channel_t *chan) /* * Process cells until we're done or find one we have no current handler * for. + * + * We must free the cells here after calling the handler, since custody + * of the buffer was given to the channel layer when they were queued; + * see comments on memory management in channel_queue_cell() and in + * channel_queue_var_cell() below. */ while (NULL != (q = TOR_SIMPLEQ_FIRST(&chan->incoming_queue))) { tor_assert(q); @@ -2669,6 +2678,7 @@ channel_process_cells(channel_t *chan) q->u.fixed.cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->cell_handler(chan, q->u.fixed.cell); + tor_free(q->u.fixed.cell); tor_free(q); } else if (q->type == CELL_QUEUE_VAR && chan->var_cell_handler) { @@ -2681,6 +2691,7 @@ channel_process_cells(channel_t *chan) q->u.var.var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->var_cell_handler(chan, q->u.var.var_cell); + tor_free(q->u.var.var_cell); tor_free(q); } else { /* Can't handle this one */ @@ -2701,6 +2712,7 @@ channel_queue_cell(channel_t *chan, cell_t *cell) { int need_to_queue = 0; cell_queue_entry_t *q; + cell_t *cell_copy = NULL; tor_assert(chan); tor_assert(cell); @@ -2728,8 +2740,19 @@ channel_queue_cell(channel_t *chan, cell_t *cell) U64_PRINTF_ARG(chan->global_identifier)); chan->cell_handler(chan, cell); } else { - /* Otherwise queue it and then process the queue if possible. */ - q = cell_queue_entry_new_fixed(cell); + /* + * Otherwise queue it and then process the queue if possible. + * + * We queue a copy, not the original pointer - it might have been on the + * stack in connection_or_process_cells_from_inbuf() (or another caller + * if we ever have a subclass other than channel_tls_t), or be freed + * there after we return. This is the uncommon case; the non-copying + * fast path occurs in the if (!need_to_queue) case above when the + * upper layer has installed cell handlers. + */ + cell_copy = tor_malloc_zero(sizeof(cell_t)); + memcpy(cell_copy, cell, sizeof(cell_t)); + q = cell_queue_entry_new_fixed(cell_copy); log_debug(LD_CHANNEL, "Queueing incoming cell_t %p for channel %p " "(global ID " U64_FORMAT ")", @@ -2755,6 +2778,7 @@ channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell) { int need_to_queue = 0; cell_queue_entry_t *q; + var_cell_t *cell_copy = NULL; tor_assert(chan); tor_assert(var_cell); @@ -2783,8 +2807,18 @@ channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell) U64_PRINTF_ARG(chan->global_identifier)); chan->var_cell_handler(chan, var_cell); } else { - /* Otherwise queue it and then process the queue if possible. */ - q = cell_queue_entry_new_var(var_cell); + /* + * Otherwise queue it and then process the queue if possible. + * + * We queue a copy, not the original pointer - it might have been on the + * stack in connection_or_process_cells_from_inbuf() (or another caller + * if we ever have a subclass other than channel_tls_t), or be freed + * there after we return. This is the uncommon case; the non-copying + * fast path occurs in the if (!need_to_queue) case above when the + * upper layer has installed cell handlers. + */ + cell_copy = var_cell_copy(var_cell); + q = cell_queue_entry_new_var(cell_copy); log_debug(LD_CHANNEL, "Queueing incoming var_cell_t %p for channel %p " "(global ID " U64_FORMAT ")", @@ -2834,7 +2868,7 @@ channel_assert_counter_consistency(void) (n_channel_bytes_in_queues + n_channel_bytes_passed_to_lower_layer)); } -/** DOCDOC */ +/* DOCDOC */ static int is_destroy_cell(channel_t *chan, const cell_queue_entry_t *q, circid_t *circid_out) |