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Diffstat (limited to 'lib/rconn.c')
| -rw-r--r-- | lib/rconn.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/lib/rconn.c b/lib/rconn.c new file mode 100644 index 000000000..ead8d2d6a --- /dev/null +++ b/lib/rconn.c @@ -0,0 +1,959 @@ +/* + * Copyright (c) 2008, 2009 Nicira Networks. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <config.h> +#include "rconn.h" +#include <assert.h> +#include <errno.h> +#include <limits.h> +#include <stdlib.h> +#include <string.h> +#include "coverage.h" +#include "ofpbuf.h" +#include "openflow/openflow.h" +#include "poll-loop.h" +#include "sat-math.h" +#include "timeval.h" +#include "util.h" +#include "vconn.h" + +#define THIS_MODULE VLM_rconn +#include "vlog.h" + +#define STATES \ + STATE(VOID, 1 << 0) \ + STATE(BACKOFF, 1 << 1) \ + STATE(CONNECTING, 1 << 2) \ + STATE(ACTIVE, 1 << 3) \ + STATE(IDLE, 1 << 4) +enum state { +#define STATE(NAME, VALUE) S_##NAME = VALUE, + STATES +#undef STATE +}; + +static const char * +state_name(enum state state) +{ + switch (state) { +#define STATE(NAME, VALUE) case S_##NAME: return #NAME; + STATES +#undef STATE + } + return "***ERROR***"; +} + +/* A reliable connection to an OpenFlow switch or controller. + * + * See the large comment in rconn.h for more information. */ +struct rconn { + enum state state; + time_t state_entered; + + struct vconn *vconn; + char *name; + bool reliable; + + struct ovs_queue txq; + + int backoff; + int max_backoff; + time_t backoff_deadline; + time_t last_received; + time_t last_connected; + unsigned int packets_sent; + unsigned int seqno; + + /* In S_ACTIVE and S_IDLE, probably_admitted reports whether we believe + * that the peer has made a (positive) admission control decision on our + * connection. If we have not yet been (probably) admitted, then the + * connection does not reset the timer used for deciding whether the switch + * should go into fail-open mode. + * + * last_admitted reports the last time we believe such a positive admission + * control decision was made. */ + bool probably_admitted; + time_t last_admitted; + + /* These values are simply for statistics reporting, not used directly by + * anything internal to the rconn (or the secchan for that matter). */ + unsigned int packets_received; + unsigned int n_attempted_connections, n_successful_connections; + time_t creation_time; + unsigned long int total_time_connected; + + /* If we can't connect to the peer, it could be for any number of reasons. + * Usually, one would assume it is because the peer is not running or + * because the network is partitioned. But it could also be because the + * network topology has changed, in which case the upper layer will need to + * reassess it (in particular, obtain a new IP address via DHCP and find + * the new location of the controller). We set this flag when we suspect + * that this could be the case. */ + bool questionable_connectivity; + time_t last_questioned; + + /* Throughout this file, "probe" is shorthand for "inactivity probe". + * When nothing has been received from the peer for a while, we send out + * an echo request as an inactivity probe packet. We should receive back + * a response. */ + int probe_interval; /* Secs of inactivity before sending probe. */ + + /* Messages sent or received are copied to the monitor connections. */ +#define MAX_MONITORS 8 + struct vconn *monitors[8]; + size_t n_monitors; +}; + +static unsigned int elapsed_in_this_state(const struct rconn *); +static unsigned int timeout(const struct rconn *); +static bool timed_out(const struct rconn *); +static void state_transition(struct rconn *, enum state); +static int try_send(struct rconn *); +static int reconnect(struct rconn *); +static void disconnect(struct rconn *, int error); +static void flush_queue(struct rconn *); +static void question_connectivity(struct rconn *); +static void copy_to_monitor(struct rconn *, const struct ofpbuf *); +static bool is_connected_state(enum state); +static bool is_admitted_msg(const struct ofpbuf *); + +/* Creates a new rconn, connects it (reliably) to 'name', and returns it. */ +struct rconn * +rconn_new(const char *name, int inactivity_probe_interval, int max_backoff) +{ + struct rconn *rc = rconn_create(inactivity_probe_interval, max_backoff); + rconn_connect(rc, name); + return rc; +} + +/* Creates a new rconn, connects it (unreliably) to 'vconn', and returns it. */ +struct rconn * +rconn_new_from_vconn(const char *name, struct vconn *vconn) +{ + struct rconn *rc = rconn_create(60, 0); + rconn_connect_unreliably(rc, name, vconn); + return rc; +} + +/* Creates and returns a new rconn. + * + * 'probe_interval' is a number of seconds. If the interval passes once + * without an OpenFlow message being received from the peer, the rconn sends + * out an "echo request" message. If the interval passes again without a + * message being received, the rconn disconnects and re-connects to the peer. + * Setting 'probe_interval' to 0 disables this behavior. + * + * 'max_backoff' is the maximum number of seconds between attempts to connect + * to the peer. The actual interval starts at 1 second and doubles on each + * failure until it reaches 'max_backoff'. If 0 is specified, the default of + * 60 seconds is used. */ +struct rconn * +rconn_create(int probe_interval, int max_backoff) +{ + struct rconn *rc = xcalloc(1, sizeof *rc); + + rc->state = S_VOID; + rc->state_entered = time_now(); + + rc->vconn = NULL; + rc->name = xstrdup("void"); + rc->reliable = false; + + queue_init(&rc->txq); + + rc->backoff = 0; + rc->max_backoff = max_backoff ? max_backoff : 60; + rc->backoff_deadline = TIME_MIN; + rc->last_received = time_now(); + rc->last_connected = time_now(); + rc->seqno = 0; + + rc->packets_sent = 0; + + rc->probably_admitted = false; + rc->last_admitted = time_now(); + + rc->packets_received = 0; + rc->n_attempted_connections = 0; + rc->n_successful_connections = 0; + rc->creation_time = time_now(); + rc->total_time_connected = 0; + + rc->questionable_connectivity = false; + rc->last_questioned = time_now(); + + rconn_set_probe_interval(rc, probe_interval); + + rc->n_monitors = 0; + + return rc; +} + +void +rconn_set_max_backoff(struct rconn *rc, int max_backoff) +{ + rc->max_backoff = MAX(1, max_backoff); + if (rc->state == S_BACKOFF && rc->backoff > max_backoff) { + rc->backoff = max_backoff; + if (rc->backoff_deadline > time_now() + max_backoff) { + rc->backoff_deadline = time_now() + max_backoff; + } + } +} + +int +rconn_get_max_backoff(const struct rconn *rc) +{ + return rc->max_backoff; +} + +void +rconn_set_probe_interval(struct rconn *rc, int probe_interval) +{ + rc->probe_interval = probe_interval ? MAX(5, probe_interval) : 0; +} + +int +rconn_get_probe_interval(const struct rconn *rc) +{ + return rc->probe_interval; +} + +int +rconn_connect(struct rconn *rc, const char *name) +{ + rconn_disconnect(rc); + free(rc->name); + rc->name = xstrdup(name); + rc->reliable = true; + return reconnect(rc); +} + +void +rconn_connect_unreliably(struct rconn *rc, + const char *name, struct vconn *vconn) +{ + assert(vconn != NULL); + rconn_disconnect(rc); + free(rc->name); + rc->name = xstrdup(name); + rc->reliable = false; + rc->vconn = vconn; + rc->last_connected = time_now(); + state_transition(rc, S_ACTIVE); +} + +/* If 'rc' is connected, forces it to drop the connection and reconnect. */ +void +rconn_reconnect(struct rconn *rc) +{ + if (rc->state & (S_ACTIVE | S_IDLE)) { + disconnect(rc, 0); + } +} + +void +rconn_disconnect(struct rconn *rc) +{ + if (rc->state != S_VOID) { + if (rc->vconn) { + vconn_close(rc->vconn); + rc->vconn = NULL; + } + free(rc->name); + rc->name = xstrdup("void"); + rc->reliable = false; + + rc->backoff = 0; + rc->backoff_deadline = TIME_MIN; + + state_transition(rc, S_VOID); + } +} + +/* Disconnects 'rc' and frees the underlying storage. */ +void +rconn_destroy(struct rconn *rc) +{ + if (rc) { + size_t i; + + free(rc->name); + vconn_close(rc->vconn); + flush_queue(rc); + queue_destroy(&rc->txq); + for (i = 0; i < rc->n_monitors; i++) { + vconn_close(rc->monitors[i]); + } + free(rc); + } +} + +static unsigned int +timeout_VOID(const struct rconn *rc UNUSED) +{ + return UINT_MAX; +} + +static void +run_VOID(struct rconn *rc UNUSED) +{ + /* Nothing to do. */ +} + +static int +reconnect(struct rconn *rc) +{ + int retval; + + VLOG_INFO("%s: connecting...", rc->name); + rc->n_attempted_connections++; + retval = vconn_open(rc->name, OFP_VERSION, &rc->vconn); + if (!retval) { + rc->backoff_deadline = time_now() + rc->backoff; + state_transition(rc, S_CONNECTING); + } else { + VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(retval)); + rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */ + disconnect(rc, 0); + } + return retval; +} + +static unsigned int +timeout_BACKOFF(const struct rconn *rc) +{ + return rc->backoff; +} + +static void +run_BACKOFF(struct rconn *rc) +{ + if (timed_out(rc)) { + reconnect(rc); + } +} + +static unsigned int +timeout_CONNECTING(const struct rconn *rc) +{ + return MAX(1, rc->backoff); +} + +static void +run_CONNECTING(struct rconn *rc) +{ + int retval = vconn_connect(rc->vconn); + if (!retval) { + VLOG_INFO("%s: connected", rc->name); + rc->n_successful_connections++; + state_transition(rc, S_ACTIVE); + rc->last_connected = rc->state_entered; + } else if (retval != EAGAIN) { + VLOG_INFO("%s: connection failed (%s)", rc->name, strerror(retval)); + disconnect(rc, retval); + } else if (timed_out(rc)) { + VLOG_INFO("%s: connection timed out", rc->name); + rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */ + disconnect(rc, 0); + } +} + +static void +do_tx_work(struct rconn *rc) +{ + if (!rc->txq.n) { + return; + } + while (rc->txq.n > 0) { + int error = try_send(rc); + if (error) { + break; + } + } + if (!rc->txq.n) { + poll_immediate_wake(); + } +} + +static unsigned int +timeout_ACTIVE(const struct rconn *rc) +{ + if (rc->probe_interval) { + unsigned int base = MAX(rc->last_received, rc->state_entered); + unsigned int arg = base + rc->probe_interval - rc->state_entered; + return arg; + } + return UINT_MAX; +} + +static void +run_ACTIVE(struct rconn *rc) +{ + if (timed_out(rc)) { + unsigned int base = MAX(rc->last_received, rc->state_entered); + VLOG_DBG("%s: idle %u seconds, sending inactivity probe", + rc->name, (unsigned int) (time_now() - base)); + + /* Ordering is important here: rconn_send() can transition to BACKOFF, + * and we don't want to transition back to IDLE if so, because then we + * can end up queuing a packet with vconn == NULL and then *boom*. */ + state_transition(rc, S_IDLE); + rconn_send(rc, make_echo_request(), NULL); + return; + } + + do_tx_work(rc); +} + +static unsigned int +timeout_IDLE(const struct rconn *rc) +{ + return rc->probe_interval; +} + +static void +run_IDLE(struct rconn *rc) +{ + if (timed_out(rc)) { + question_connectivity(rc); + VLOG_ERR("%s: no response to inactivity probe after %u " + "seconds, disconnecting", + rc->name, elapsed_in_this_state(rc)); + disconnect(rc, 0); + } else { + do_tx_work(rc); + } +} + +/* Performs whatever activities are necessary to maintain 'rc': if 'rc' is + * disconnected, attempts to (re)connect, backing off as necessary; if 'rc' is + * connected, attempts to send packets in the send queue, if any. */ +void +rconn_run(struct rconn *rc) +{ + int old_state; + do { + old_state = rc->state; + switch (rc->state) { +#define STATE(NAME, VALUE) case S_##NAME: run_##NAME(rc); break; + STATES +#undef STATE + default: + NOT_REACHED(); + } + } while (rc->state != old_state); +} + +/* Causes the next call to poll_block() to wake up when rconn_run() should be + * called on 'rc'. */ +void +rconn_run_wait(struct rconn *rc) +{ + unsigned int timeo = timeout(rc); + if (timeo != UINT_MAX) { + unsigned int expires = sat_add(rc->state_entered, timeo); + unsigned int remaining = sat_sub(expires, time_now()); + poll_timer_wait(sat_mul(remaining, 1000)); + } + + if ((rc->state & (S_ACTIVE | S_IDLE)) && rc->txq.n) { + vconn_wait(rc->vconn, WAIT_SEND); + } +} + +/* Attempts to receive a packet from 'rc'. If successful, returns the packet; + * otherwise, returns a null pointer. The caller is responsible for freeing + * the packet (with ofpbuf_delete()). */ +struct ofpbuf * +rconn_recv(struct rconn *rc) +{ + if (rc->state & (S_ACTIVE | S_IDLE)) { + struct ofpbuf *buffer; + int error = vconn_recv(rc->vconn, &buffer); + if (!error) { + copy_to_monitor(rc, buffer); + if (is_admitted_msg(buffer) + || time_now() - rc->last_connected >= 30) { + rc->probably_admitted = true; + rc->last_admitted = time_now(); + } + rc->last_received = time_now(); + rc->packets_received++; + if (rc->state == S_IDLE) { + state_transition(rc, S_ACTIVE); + } + return buffer; + } else if (error != EAGAIN) { + disconnect(rc, error); + } + } + return NULL; +} + +/* Causes the next call to poll_block() to wake up when a packet may be ready + * to be received by vconn_recv() on 'rc'. */ +void +rconn_recv_wait(struct rconn *rc) +{ + if (rc->vconn) { + vconn_wait(rc->vconn, WAIT_RECV); + } +} + +/* Sends 'b' on 'rc'. Returns 0 if successful (in which case 'b' is + * destroyed), or ENOTCONN if 'rc' is not currently connected (in which case + * the caller retains ownership of 'b'). + * + * If 'counter' is non-null, then 'counter' will be incremented while the + * packet is in flight, then decremented when it has been sent (or discarded + * due to disconnection). Because 'b' may be sent (or discarded) before this + * function returns, the caller may not be able to observe any change in + * 'counter'. + * + * There is no rconn_send_wait() function: an rconn has a send queue that it + * takes care of sending if you call rconn_run(), which will have the side + * effect of waking up poll_block(). */ +int +rconn_send(struct rconn *rc, struct ofpbuf *b, + struct rconn_packet_counter *counter) +{ + if (rconn_is_connected(rc)) { + COVERAGE_INC(rconn_queued); + copy_to_monitor(rc, b); + b->private = counter; + if (counter) { + rconn_packet_counter_inc(counter); + } + queue_push_tail(&rc->txq, b); + + /* If the queue was empty before we added 'b', try to send some + * packets. (But if the queue had packets in it, it's because the + * vconn is backlogged and there's no point in stuffing more into it + * now. We'll get back to that in rconn_run().) */ + if (rc->txq.n == 1) { + try_send(rc); + } + return 0; + } else { + return ENOTCONN; + } +} + +/* Sends 'b' on 'rc'. Increments 'counter' while the packet is in flight; it + * will be decremented when it has been sent (or discarded due to + * disconnection). Returns 0 if successful, EAGAIN if 'counter->n' is already + * at least as large as 'queue_limit', or ENOTCONN if 'rc' is not currently + * connected. Regardless of return value, 'b' is destroyed. + * + * Because 'b' may be sent (or discarded) before this function returns, the + * caller may not be able to observe any change in 'counter'. + * + * There is no rconn_send_wait() function: an rconn has a send queue that it + * takes care of sending if you call rconn_run(), which will have the side + * effect of waking up poll_block(). */ +int +rconn_send_with_limit(struct rconn *rc, struct ofpbuf *b, + struct rconn_packet_counter *counter, int queue_limit) +{ + int retval; + retval = counter->n >= queue_limit ? EAGAIN : rconn_send(rc, b, counter); + if (retval) { + COVERAGE_INC(rconn_overflow); + ofpbuf_delete(b); + } + return retval; +} + +/* Returns the total number of packets successfully sent on the underlying + * vconn. A packet is not counted as sent while it is still queued in the + * rconn, only when it has been successfuly passed to the vconn. */ +unsigned int +rconn_packets_sent(const struct rconn *rc) +{ + return rc->packets_sent; +} + +/* Adds 'vconn' to 'rc' as a monitoring connection, to which all messages sent + * and received on 'rconn' will be copied. 'rc' takes ownership of 'vconn'. */ +void +rconn_add_monitor(struct rconn *rc, struct vconn *vconn) +{ + if (rc->n_monitors < ARRAY_SIZE(rc->monitors)) { + VLOG_INFO("new monitor connection from %s", vconn_get_name(vconn)); + rc->monitors[rc->n_monitors++] = vconn; + } else { + VLOG_DBG("too many monitor connections, discarding %s", + vconn_get_name(vconn)); + vconn_close(vconn); + } +} + +/* Returns 'rc''s name (the 'name' argument passed to rconn_new()). */ +const char * +rconn_get_name(const struct rconn *rc) +{ + return rc->name; +} + +/* Returns true if 'rconn' is connected or in the process of reconnecting, + * false if 'rconn' is disconnected and will not reconnect on its own. */ +bool +rconn_is_alive(const struct rconn *rconn) +{ + return rconn->state != S_VOID; +} + +/* Returns true if 'rconn' is connected, false otherwise. */ +bool +rconn_is_connected(const struct rconn *rconn) +{ + return is_connected_state(rconn->state); +} + +/* Returns 0 if 'rconn' is connected. Otherwise, if 'rconn' is in a "failure + * mode" (that is, it is not connected), returns the number of seconds that it + * has been in failure mode, ignoring any times that it connected but the + * controller's admission control policy caused it to be quickly + * disconnected. */ +int +rconn_failure_duration(const struct rconn *rconn) +{ + return rconn_is_connected(rconn) ? 0 : time_now() - rconn->last_admitted; +} + +/* Returns the IP address of the peer, or 0 if the peer is not connected over + * an IP-based protocol or if its IP address is not known. */ +uint32_t +rconn_get_ip(const struct rconn *rconn) +{ + return rconn->vconn ? vconn_get_ip(rconn->vconn) : 0; +} + +/* If 'rconn' can't connect to the peer, it could be for any number of reasons. + * Usually, one would assume it is because the peer is not running or because + * the network is partitioned. But it could also be because the network + * topology has changed, in which case the upper layer will need to reassess it + * (in particular, obtain a new IP address via DHCP and find the new location + * of the controller). When this appears that this might be the case, this + * function returns true. It also clears the questionability flag and prevents + * it from being set again for some time. */ +bool +rconn_is_connectivity_questionable(struct rconn *rconn) +{ + bool questionable = rconn->questionable_connectivity; + rconn->questionable_connectivity = false; + return questionable; +} + +/* Returns the total number of packets successfully received by the underlying + * vconn. */ +unsigned int +rconn_packets_received(const struct rconn *rc) +{ + return rc->packets_received; +} + +/* Returns a string representing the internal state of 'rc'. The caller must + * not modify or free the string. */ +const char * +rconn_get_state(const struct rconn *rc) +{ + return state_name(rc->state); +} + +/* Returns the number of connection attempts made by 'rc', including any + * ongoing attempt that has not yet succeeded or failed. */ +unsigned int +rconn_get_attempted_connections(const struct rconn *rc) +{ + return rc->n_attempted_connections; +} + +/* Returns the number of successful connection attempts made by 'rc'. */ +unsigned int +rconn_get_successful_connections(const struct rconn *rc) +{ + return rc->n_successful_connections; +} + +/* Returns the time at which the last successful connection was made by + * 'rc'. */ +time_t +rconn_get_last_connection(const struct rconn *rc) +{ + return rc->last_connected; +} + +/* Returns the time at which 'rc' was created. */ +time_t +rconn_get_creation_time(const struct rconn *rc) +{ + return rc->creation_time; +} + +/* Returns the approximate number of seconds that 'rc' has been connected. */ +unsigned long int +rconn_get_total_time_connected(const struct rconn *rc) +{ + return (rc->total_time_connected + + (rconn_is_connected(rc) ? elapsed_in_this_state(rc) : 0)); +} + +/* Returns the current amount of backoff, in seconds. This is the amount of + * time after which the rconn will transition from BACKOFF to CONNECTING. */ +int +rconn_get_backoff(const struct rconn *rc) +{ + return rc->backoff; +} + +/* Returns the number of seconds spent in this state so far. */ +unsigned int +rconn_get_state_elapsed(const struct rconn *rc) +{ + return elapsed_in_this_state(rc); +} + +/* Returns 'rc''s current connection sequence number, a number that changes + * every time that 'rconn' connects or disconnects. */ +unsigned int +rconn_get_connection_seqno(const struct rconn *rc) +{ + return rc->seqno; +} + +struct rconn_packet_counter * +rconn_packet_counter_create(void) +{ + struct rconn_packet_counter *c = xmalloc(sizeof *c); + c->n = 0; + c->ref_cnt = 1; + return c; +} + +void +rconn_packet_counter_destroy(struct rconn_packet_counter *c) +{ + if (c) { + assert(c->ref_cnt > 0); + if (!--c->ref_cnt && !c->n) { + free(c); + } + } +} + +void +rconn_packet_counter_inc(struct rconn_packet_counter *c) +{ + c->n++; +} + +void +rconn_packet_counter_dec(struct rconn_packet_counter *c) +{ + assert(c->n > 0); + if (!--c->n && !c->ref_cnt) { + free(c); + } +} + +/* Tries to send a packet from 'rc''s send buffer. Returns 0 if successful, + * otherwise a positive errno value. */ +static int +try_send(struct rconn *rc) +{ + int retval = 0; + struct ofpbuf *next = rc->txq.head->next; + struct rconn_packet_counter *counter = rc->txq.head->private; + retval = vconn_send(rc->vconn, rc->txq.head); + if (retval) { + if (retval != EAGAIN) { + disconnect(rc, retval); + } + return retval; + } + COVERAGE_INC(rconn_sent); + rc->packets_sent++; + if (counter) { + rconn_packet_counter_dec(counter); + } + queue_advance_head(&rc->txq, next); + return 0; +} + +/* Disconnects 'rc'. 'error' is used only for logging purposes. If it is + * nonzero, then it should be EOF to indicate the connection was closed by the + * peer in a normal fashion or a positive errno value. */ +static void +disconnect(struct rconn *rc, int error) +{ + if (rc->reliable) { + time_t now = time_now(); + + if (rc->state & (S_CONNECTING | S_ACTIVE | S_IDLE)) { + if (error > 0) { + VLOG_WARN("%s: connection dropped (%s)", + rc->name, strerror(error)); + } else if (error == EOF) { + if (rc->reliable) { + VLOG_INFO("%s: connection closed by peer", rc->name); + } + } else { + VLOG_INFO("%s: connection dropped", rc->name); + } + vconn_close(rc->vconn); + rc->vconn = NULL; + flush_queue(rc); + } + + if (now >= rc->backoff_deadline) { + rc->backoff = 1; + } else { + rc->backoff = MIN(rc->max_backoff, MAX(1, 2 * rc->backoff)); + VLOG_INFO("%s: waiting %d seconds before reconnect\n", + rc->name, rc->backoff); + } + rc->backoff_deadline = now + rc->backoff; + state_transition(rc, S_BACKOFF); + if (now - rc->last_connected > 60) { + question_connectivity(rc); + } + } else { + rconn_disconnect(rc); + } +} + +/* Drops all the packets from 'rc''s send queue and decrements their queue + * counts. */ +static void +flush_queue(struct rconn *rc) +{ + if (!rc->txq.n) { + return; + } + while (rc->txq.n > 0) { + struct ofpbuf *b = queue_pop_head(&rc->txq); + struct rconn_packet_counter *counter = b->private; + if (counter) { + rconn_packet_counter_dec(counter); + } + COVERAGE_INC(rconn_discarded); + ofpbuf_delete(b); + } + poll_immediate_wake(); +} + +static unsigned int +elapsed_in_this_state(const struct rconn *rc) +{ + return time_now() - rc->state_entered; +} + +static unsigned int +timeout(const struct rconn *rc) +{ + switch (rc->state) { +#define STATE(NAME, VALUE) case S_##NAME: return timeout_##NAME(rc); + STATES +#undef STATE + default: + NOT_REACHED(); + } +} + +static bool +timed_out(const struct rconn *rc) +{ + return time_now() >= sat_add(rc->state_entered, timeout(rc)); +} + +static void +state_transition(struct rconn *rc, enum state state) +{ + rc->seqno += (rc->state == S_ACTIVE) != (state == S_ACTIVE); + if (is_connected_state(state) && !is_connected_state(rc->state)) { + rc->probably_admitted = false; + } + if (rconn_is_connected(rc)) { + rc->total_time_connected += elapsed_in_this_state(rc); + } + VLOG_DBG("%s: entering %s", rc->name, state_name(state)); + rc->state = state; + rc->state_entered = time_now(); +} + +static void +question_connectivity(struct rconn *rc) +{ + time_t now = time_now(); + if (now - rc->last_questioned > 60) { + rc->questionable_connectivity = true; + rc->last_questioned = now; + } +} + +static void +copy_to_monitor(struct rconn *rc, const struct ofpbuf *b) +{ + struct ofpbuf *clone = NULL; + int retval; + size_t i; + + for (i = 0; i < rc->n_monitors; ) { + struct vconn *vconn = rc->monitors[i]; + + if (!clone) { + clone = ofpbuf_clone(b); + } + retval = vconn_send(vconn, clone); + if (!retval) { + clone = NULL; + } else if (retval != EAGAIN) { + VLOG_DBG("%s: closing monitor connection to %s: %s", + rconn_get_name(rc), vconn_get_name(vconn), + strerror(retval)); + rc->monitors[i] = rc->monitors[--rc->n_monitors]; + continue; + } + i++; + } + ofpbuf_delete(clone); +} + +static bool +is_connected_state(enum state state) +{ + return (state & (S_ACTIVE | S_IDLE)) != 0; +} + +static bool +is_admitted_msg(const struct ofpbuf *b) +{ + struct ofp_header *oh = b->data; + uint8_t type = oh->type; + return !(type < 32 + && (1u << type) & ((1u << OFPT_HELLO) | + (1u << OFPT_ERROR) | + (1u << OFPT_ECHO_REQUEST) | + (1u << OFPT_ECHO_REPLY) | + (1u << OFPT_VENDOR) | + (1u << OFPT_FEATURES_REQUEST) | + (1u << OFPT_FEATURES_REPLY) | + (1u << OFPT_GET_CONFIG_REQUEST) | + (1u << OFPT_GET_CONFIG_REPLY) | + (1u << OFPT_SET_CONFIG))); +} |