X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fnetdev.c;h=24c2a88fa3f38aaeb6e75db9991cfc13c58a0aa3;hb=refs%2Fheads%2Flts-1.0a;hp=2c7b260e1234544857083492e0a42b68b1ff3eba;hpb=a0bc29a541fc7dc6e20137d5558e2094d614e6ab;p=sliver-openvswitch.git diff --git a/lib/netdev.c b/lib/netdev.c index 2c7b260e1..24c2a88fa 100644 --- a/lib/netdev.c +++ b/lib/netdev.c @@ -37,14 +37,18 @@ #include "poll-loop.h" #include "shash.h" #include "svec.h" - -#define THIS_MODULE VLM_netdev #include "vlog.h" +VLOG_DEFINE_THIS_MODULE(netdev) + static const struct netdev_class *base_netdev_classes[] = { +#ifdef HAVE_NETLINK &netdev_linux_class, &netdev_tap_class, + &netdev_patch_class, &netdev_gre_class, + &netdev_capwap_class, +#endif }; static struct shash netdev_classes = SHASH_INITIALIZER(&netdev_classes); @@ -204,7 +208,7 @@ compare_device_args(const struct netdev_dev *dev, const struct shash *args) new_args = shash_sort(args); for (i = 0; i < dev->n_args; i++) { - if (strcmp(dev->args[i].key, new_args[i]->name) || + if (strcmp(dev->args[i].key, new_args[i]->name) || strcmp(dev->args[i].value, new_args[i]->data)) { result = false; goto finish; @@ -262,12 +266,6 @@ create_device(struct netdev_options *options, struct netdev_dev **netdev_devp) { struct netdev_class *netdev_class; - if (!options->may_create) { - VLOG_WARN("attempted to create a device that may not be created: %s", - options->name); - return ENODEV; - } - if (!options->type || strlen(options->type) == 0) { /* Default to system. */ options->type = "system"; @@ -275,8 +273,6 @@ create_device(struct netdev_options *options, struct netdev_dev **netdev_devp) netdev_class = shash_find_data(&netdev_classes, options->type); if (!netdev_class) { - VLOG_WARN("could not create netdev %s of unknown type %s", - options->name, options->type); return EAFNOSUPPORT; } @@ -294,15 +290,7 @@ create_device(struct netdev_options *options, struct netdev_dev **netdev_devp) * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order to * capture frames of that type received on the device. It may also be one of * the 'enum netdev_pseudo_ethertype' values to receive frames in one of those - * categories. - * - * If the 'may_create' flag is set then this is allowed to be the first time - * the device is opened (i.e. the refcount will be 1 after this call). It - * may be set to false if the device should have already been created. - * - * If the 'may_open' flag is set then the call will succeed even if another - * caller has already opened it. It may be to false if the device should not - * currently be open. */ + * categories. */ int netdev_open(struct netdev_options *options, struct netdev **netdevp) @@ -323,25 +311,23 @@ netdev_open(struct netdev_options *options, struct netdev **netdevp) if (!netdev_dev) { error = create_device(options, &netdev_dev); if (error) { + if (error == EAFNOSUPPORT) { + VLOG_WARN("could not create netdev %s of unknown type %s", + options->name, options->type); + } return error; } update_device_args(netdev_dev, options->args); - } else if (options->may_open) { - if (!shash_is_empty(options->args) && - !compare_device_args(netdev_dev, options->args)) { + } else if (!shash_is_empty(options->args) && + !compare_device_args(netdev_dev, options->args)) { - VLOG_WARN("%s: attempted to open already created netdev with " - "different arguments", options->name); - return EINVAL; - } - } else { - VLOG_WARN("%s: attempted to create a netdev device with bound name", - options->name); - return EEXIST; + VLOG_WARN("%s: attempted to open already open netdev with " + "different arguments", options->name); + return EINVAL; } - error = netdev_dev->netdev_class->open(netdev_dev, options->ethertype, + error = netdev_dev->netdev_class->open(netdev_dev, options->ethertype, netdevp); if (!error) { @@ -361,11 +347,8 @@ netdev_open_default(const char *name, struct netdev **netdevp) struct netdev_options options; memset(&options, 0, sizeof options); - options.name = name; options.ethertype = NETDEV_ETH_TYPE_NONE; - options.may_create = true; - options.may_open = true; return netdev_open(&options, netdevp); } @@ -434,6 +417,14 @@ netdev_exists(const char *name) } } +/* Returns true if a network device named 'name' is currently opened, + * otherwise false. */ +bool +netdev_is_open(const char *name) +{ + return !!shash_find_data(&netdev_dev_shash, name); +} + /* Clears 'svec' and enumerates the names of all known network devices. */ int netdev_enumerate(struct svec *svec) @@ -472,17 +463,23 @@ netdev_enumerate(struct svec *svec) * guaranteed to contain at least ETH_TOTAL_MIN bytes. Otherwise, returns a * positive errno value. Returns EAGAIN immediately if no packet is ready to * be returned. + * + * Some network devices may not implement support for this function. In such + * cases this function will always return EOPNOTSUPP. */ int netdev_recv(struct netdev *netdev, struct ofpbuf *buffer) { + int (*recv)(struct netdev *, void *, size_t); int retval; assert(buffer->size == 0); assert(ofpbuf_tailroom(buffer) >= ETH_TOTAL_MIN); - retval = netdev_get_dev(netdev)->netdev_class->recv(netdev, buffer->data, - ofpbuf_tailroom(buffer)); + recv = netdev_get_dev(netdev)->netdev_class->recv; + retval = (recv + ? (recv)(netdev, buffer->data, ofpbuf_tailroom(buffer)) + : -EOPNOTSUPP); if (retval >= 0) { COVERAGE_INC(netdev_received); buffer->size += retval; @@ -500,14 +497,22 @@ netdev_recv(struct netdev *netdev, struct ofpbuf *buffer) void netdev_recv_wait(struct netdev *netdev) { - netdev_get_dev(netdev)->netdev_class->recv_wait(netdev); + void (*recv_wait)(struct netdev *); + + recv_wait = netdev_get_dev(netdev)->netdev_class->recv_wait; + if (recv_wait) { + recv_wait(netdev); + } } /* Discards all packets waiting to be received from 'netdev'. */ int netdev_drain(struct netdev *netdev) { - return netdev_get_dev(netdev)->netdev_class->drain(netdev); + int (*drain)(struct netdev *); + + drain = netdev_get_dev(netdev)->netdev_class->drain; + return drain ? drain(netdev) : 0; } /* Sends 'buffer' on 'netdev'. Returns 0 if successful, otherwise a positive @@ -518,12 +523,18 @@ netdev_drain(struct netdev *netdev) * The caller retains ownership of 'buffer' in all cases. * * The kernel maintains a packet transmission queue, so the caller is not - * expected to do additional queuing of packets. */ + * expected to do additional queuing of packets. + * + * Some network devices may not implement support for this function. In such + * cases this function will always return EOPNOTSUPP. */ int netdev_send(struct netdev *netdev, const struct ofpbuf *buffer) { - int error = netdev_get_dev(netdev)->netdev_class->send(netdev, - buffer->data, buffer->size); + int (*send)(struct netdev *, const void *, size_t); + int error; + + send = netdev_get_dev(netdev)->netdev_class->send; + error = send ? (send)(netdev, buffer->data, buffer->size) : EOPNOTSUPP; if (!error) { COVERAGE_INC(netdev_sent); } @@ -540,7 +551,12 @@ netdev_send(struct netdev *netdev, const struct ofpbuf *buffer) void netdev_send_wait(struct netdev *netdev) { - return netdev_get_dev(netdev)->netdev_class->send_wait(netdev); + void (*send_wait)(struct netdev *); + + send_wait = netdev_get_dev(netdev)->netdev_class->send_wait; + if (send_wait) { + send_wait(netdev); + } } /* Attempts to set 'netdev''s MAC address to 'mac'. Returns 0 if successful, @@ -595,23 +611,37 @@ netdev_get_mtu(const struct netdev *netdev, int *mtup) * value should be unique within a host and remain stable at least until * reboot. SNMP says an ifindex "ranges between 1 and the value of ifNumber" * but many systems do not follow this rule anyhow. + * + * Some network devices may not implement support for this function. In such + * cases this function will always return -EOPNOTSUPP. */ int netdev_get_ifindex(const struct netdev *netdev) { - return netdev_get_dev(netdev)->netdev_class->get_ifindex(netdev); + int (*get_ifindex)(const struct netdev *); + + get_ifindex = netdev_get_dev(netdev)->netdev_class->get_ifindex; + + return get_ifindex ? get_ifindex(netdev) : -EOPNOTSUPP; } /* Stores the features supported by 'netdev' into each of '*current', * '*advertised', '*supported', and '*peer' that are non-null. Each value is a * bitmap of "enum ofp_port_features" bits, in host byte order. Returns 0 if * successful, otherwise a positive errno value. On failure, all of the - * passed-in values are set to 0. */ + * passed-in values are set to 0. + * + * Some network devices may not implement support for this function. In such + * cases this function will always return EOPNOTSUPP. + */ int netdev_get_features(struct netdev *netdev, uint32_t *current, uint32_t *advertised, uint32_t *supported, uint32_t *peer) { + int (*get_features)(struct netdev *netdev, + uint32_t *current, uint32_t *advertised, + uint32_t *supported, uint32_t *peer); uint32_t dummy[4]; int error; @@ -628,8 +658,10 @@ netdev_get_features(struct netdev *netdev, peer = &dummy[3]; } - error = netdev_get_dev(netdev)->netdev_class->get_features(netdev, current, - advertised, supported, peer); + get_features = netdev_get_dev(netdev)->netdev_class->get_features; + error = get_features + ? get_features(netdev, current, advertised, supported, peer) + : EOPNOTSUPP; if (error) { *current = *advertised = *supported = *peer = 0; } @@ -697,7 +729,7 @@ netdev_get_in4(const struct netdev *netdev, int error; error = (netdev_get_dev(netdev)->netdev_class->get_in4 - ? netdev_get_dev(netdev)->netdev_class->get_in4(netdev, + ? netdev_get_dev(netdev)->netdev_class->get_in4(netdev, &address, &netmask) : EOPNOTSUPP); if (address_) { @@ -772,7 +804,7 @@ netdev_get_in6(const struct netdev *netdev, struct in6_addr *in6) int error; error = (netdev_get_dev(netdev)->netdev_class->get_in6 - ? netdev_get_dev(netdev)->netdev_class->get_in6(netdev, + ? netdev_get_dev(netdev)->netdev_class->get_in6(netdev, in6 ? in6 : &dummy) : EOPNOTSUPP); if (error && in6) { @@ -793,7 +825,7 @@ do_update_flags(struct netdev *netdev, enum netdev_flags off, enum netdev_flags old_flags; int error; - error = netdev_get_dev(netdev)->netdev_class->update_flags(netdev, + error = netdev_get_dev(netdev)->netdev_class->update_flags(netdev, off & ~on, on, &old_flags); if (error) { VLOG_WARN_RL(&rl, "failed to %s flags for network device %s: %s", @@ -868,7 +900,7 @@ netdev_arp_lookup(const struct netdev *netdev, uint32_t ip, uint8_t mac[ETH_ADDR_LEN]) { int error = (netdev_get_dev(netdev)->netdev_class->arp_lookup - ? netdev_get_dev(netdev)->netdev_class->arp_lookup(netdev, + ? netdev_get_dev(netdev)->netdev_class->arp_lookup(netdev, ip, mac) : EOPNOTSUPP); if (error) { @@ -883,7 +915,7 @@ int netdev_get_carrier(const struct netdev *netdev, bool *carrier) { int error = (netdev_get_dev(netdev)->netdev_class->get_carrier - ? netdev_get_dev(netdev)->netdev_class->get_carrier(netdev, + ? netdev_get_dev(netdev)->netdev_class->get_carrier(netdev, carrier) : EOPNOTSUPP); if (error) { @@ -908,6 +940,19 @@ netdev_get_stats(const struct netdev *netdev, struct netdev_stats *stats) return error; } +/* Attempts to change the stats for 'netdev' to those provided in 'stats'. + * Returns 0 if successful, otherwise a positive errno value. + * + * This will probably fail for most network devices. Some devices might only + * allow setting their stats to 0. */ +int +netdev_set_stats(struct netdev *netdev, const struct netdev_stats *stats) +{ + return (netdev_get_dev(netdev)->netdev_class->set_stats + ? netdev_get_dev(netdev)->netdev_class->set_stats(netdev, stats) + : EOPNOTSUPP); +} + /* Attempts to set input rate limiting (policing) policy, such that up to * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative burst * size of 'kbits' kb. */ @@ -916,11 +961,290 @@ netdev_set_policing(struct netdev *netdev, uint32_t kbits_rate, uint32_t kbits_burst) { return (netdev_get_dev(netdev)->netdev_class->set_policing - ? netdev_get_dev(netdev)->netdev_class->set_policing(netdev, + ? netdev_get_dev(netdev)->netdev_class->set_policing(netdev, kbits_rate, kbits_burst) : EOPNOTSUPP); } +/* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves it + * empty if 'netdev' does not support QoS. Any names added to 'types' should + * be documented as valid for the "type" column in the "QoS" table in + * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)). + * + * Every network device supports disabling QoS with a type of "", but this type + * will not be added to 'types'. + * + * The caller must initialize 'types' (e.g. with svec_init()) before calling + * this function. The caller is responsible for destroying 'types' (e.g. with + * svec_destroy()) when it is no longer needed. + * + * Returns 0 if successful, otherwise a positive errno value. */ +int +netdev_get_qos_types(const struct netdev *netdev, struct svec *types) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + return (class->get_qos_types + ? class->get_qos_types(netdev, types) + : 0); +} + +/* Queries 'netdev' for its capabilities regarding the specified 'type' of QoS, + * which should be "" or one of the types returned by netdev_get_qos_types() + * for 'netdev'. Returns 0 if successful, otherwise a positive errno value. + * On success, initializes 'caps' with the QoS capabilities; on failure, clears + * 'caps' to all zeros. */ +int +netdev_get_qos_capabilities(const struct netdev *netdev, const char *type, + struct netdev_qos_capabilities *caps) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + + if (*type) { + int retval = (class->get_qos_capabilities + ? class->get_qos_capabilities(netdev, type, caps) + : EOPNOTSUPP); + if (retval) { + memset(caps, 0, sizeof *caps); + } + return retval; + } else { + /* Every netdev supports turning off QoS. */ + memset(caps, 0, sizeof *caps); + return 0; + } +} + +/* Obtains the number of queues supported by 'netdev' for the specified 'type' + * of QoS. Returns 0 if successful, otherwise a positive errno value. Stores + * the number of queues (zero on failure) in '*n_queuesp'. + * + * This is just a simple wrapper around netdev_get_qos_capabilities(). */ +int +netdev_get_n_queues(const struct netdev *netdev, + const char *type, unsigned int *n_queuesp) +{ + struct netdev_qos_capabilities caps; + int retval; + + retval = netdev_get_qos_capabilities(netdev, type, &caps); + *n_queuesp = caps.n_queues; + return retval; +} + +/* Queries 'netdev' about its currently configured form of QoS. If successful, + * stores the name of the current form of QoS into '*typep', stores any details + * of configuration as string key-value pairs in 'details', and returns 0. On + * failure, sets '*typep' to NULL and returns a positive errno value. + * + * A '*typep' of "" indicates that QoS is currently disabled on 'netdev'. + * + * The caller must initialize 'details' as an empty shash (e.g. with + * shash_init()) before calling this function. The caller must free 'details', + * including 'data' members, when it is no longer needed (e.g. with + * shash_destroy_free_data()). + * + * The caller must not modify or free '*typep'. + * + * '*typep' will be one of the types returned by netdev_get_qos_types() for + * 'netdev'. The contents of 'details' should be documented as valid for + * '*typep' in the "other_config" column in the "QoS" table in + * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)). */ +int +netdev_get_qos(const struct netdev *netdev, + const char **typep, struct shash *details) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + int retval; + + if (class->get_qos) { + retval = class->get_qos(netdev, typep, details); + if (retval) { + *typep = NULL; + shash_clear_free_data(details); + } + return retval; + } else { + /* 'netdev' doesn't support QoS, so report that QoS is disabled. */ + *typep = ""; + return 0; + } +} + +/* Attempts to reconfigure QoS on 'netdev', changing the form of QoS to 'type' + * with details of configuration from 'details'. Returns 0 if successful, + * otherwise a positive errno value. On error, the previous QoS configuration + * is retained. + * + * When this function changes the type of QoS (not just 'details'), this also + * resets all queue configuration for 'netdev' to their defaults (which depend + * on the specific type of QoS). Otherwise, the queue configuration for + * 'netdev' is unchanged. + * + * 'type' should be "" (to disable QoS) or one of the types returned by + * netdev_get_qos_types() for 'netdev'. The contents of 'details' should be + * documented as valid for the given 'type' in the "other_config" column in the + * "QoS" table in vswitchd/vswitch.xml (which is built as + * ovs-vswitchd.conf.db(8)). + * + * NULL may be specified for 'details' if there are no configuration + * details. */ +int +netdev_set_qos(struct netdev *netdev, + const char *type, const struct shash *details) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + + if (!type) { + type = ""; + } + + if (class->set_qos) { + if (!details) { + static struct shash empty = SHASH_INITIALIZER(&empty); + details = ∅ + } + return class->set_qos(netdev, type, details); + } else { + return *type ? EOPNOTSUPP : 0; + } +} + +/* Queries 'netdev' for information about the queue numbered 'queue_id'. If + * successful, adds that information as string key-value pairs to 'details'. + * Returns 0 if successful, otherwise a positive errno value. + * + * 'queue_id' must be less than the number of queues supported by 'netdev' for + * the current form of QoS (e.g. as returned by netdev_get_n_queues(netdev)). + * + * The returned contents of 'details' should be documented as valid for the + * given 'type' in the "other_config" column in the "Queue" table in + * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)). + * + * The caller must initialize 'details' (e.g. with shash_init()) before calling + * this function. The caller must free 'details', including 'data' members, + * when it is no longer needed (e.g. with shash_destroy_free_data()). */ +int +netdev_get_queue(const struct netdev *netdev, + unsigned int queue_id, struct shash *details) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + int retval; + + retval = (class->get_queue + ? class->get_queue(netdev, queue_id, details) + : EOPNOTSUPP); + if (retval) { + shash_clear_free_data(details); + } + return retval; +} + +/* Configures the queue numbered 'queue_id' on 'netdev' with the key-value + * string pairs in 'details'. The contents of 'details' should be documented + * as valid for the given 'type' in the "other_config" column in the "Queue" + * table in vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)). + * Returns 0 if successful, otherwise a positive errno value. On failure, the + * given queue's configuration should be unmodified. + * + * 'queue_id' must be less than the number of queues supported by 'netdev' for + * the current form of QoS (e.g. as returned by netdev_get_n_queues(netdev)). + * + * This function does not modify 'details', and the caller retains ownership of + * it. + */ +int +netdev_set_queue(struct netdev *netdev, + unsigned int queue_id, const struct shash *details) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + return (class->set_queue + ? class->set_queue(netdev, queue_id, details) + : EOPNOTSUPP); +} + +/* Attempts to delete the queue numbered 'queue_id' from 'netdev'. Some kinds + * of QoS may have a fixed set of queues, in which case attempts to delete them + * will fail with EOPNOTSUPP. + * + * Returns 0 if successful, otherwise a positive errno value. On failure, the + * given queue will be unmodified. + * + * 'queue_id' must be less than the number of queues supported by 'netdev' for + * the current form of QoS (e.g. as returned by + * netdev_get_n_queues(netdev)). */ +int +netdev_delete_queue(struct netdev *netdev, unsigned int queue_id) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + return (class->delete_queue + ? class->delete_queue(netdev, queue_id) + : EOPNOTSUPP); +} + +/* Obtains statistics about 'queue_id' on 'netdev'. On success, returns 0 and + * fills 'stats' with the queue's statistics; individual members of 'stats' may + * be set to all-1-bits if the statistic is unavailable. On failure, returns a + * positive errno value and fills 'stats' with all-1-bits. */ +int +netdev_get_queue_stats(const struct netdev *netdev, unsigned int queue_id, + struct netdev_queue_stats *stats) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + int retval; + + retval = (class->get_queue_stats + ? class->get_queue_stats(netdev, queue_id, stats) + : EOPNOTSUPP); + if (retval) { + memset(stats, 0xff, sizeof *stats); + } + return retval; +} + +/* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's ID, + * its configuration, and the 'aux' specified by the caller. The order of + * iteration is unspecified, but (when successful) each queue is visited + * exactly once. + * + * Calling this function may be more efficient than calling netdev_get_queue() + * for every queue. + * + * 'cb' must not modify or free the 'details' argument passed in. + * + * Returns 0 if successful, otherwise a positive errno value. On error, some + * configured queues may not have been included in the iteration. */ +int +netdev_dump_queues(const struct netdev *netdev, + netdev_dump_queues_cb *cb, void *aux) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + return (class->dump_queues + ? class->dump_queues(netdev, cb, aux) + : EOPNOTSUPP); +} + +/* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's ID, + * its statistics, and the 'aux' specified by the caller. The order of + * iteration is unspecified, but (when successful) each queue is visited + * exactly once. + * + * Calling this function may be more efficient than calling + * netdev_get_queue_stats() for every queue. + * + * 'cb' must not modify or free the statistics passed in. + * + * Returns 0 if successful, otherwise a positive errno value. On error, some + * configured queues may not have been included in the iteration. */ +int +netdev_dump_queue_stats(const struct netdev *netdev, + netdev_dump_queue_stats_cb *cb, void *aux) +{ + const struct netdev_class *class = netdev_get_dev(netdev)->netdev_class; + return (class->dump_queue_stats + ? class->dump_queue_stats(netdev, cb, aux) + : EOPNOTSUPP); +} + /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)), * sets '*vlan_vid' to the VLAN VID associated with that device and returns 0. * Otherwise returns a errno value (specifically ENOENT if 'netdev_name' is the @@ -930,7 +1254,7 @@ int netdev_get_vlan_vid(const struct netdev *netdev, int *vlan_vid) { int error = (netdev_get_dev(netdev)->netdev_class->get_vlan_vid - ? netdev_get_dev(netdev)->netdev_class->get_vlan_vid(netdev, + ? netdev_get_dev(netdev)->netdev_class->get_vlan_vid(netdev, vlan_vid) : ENOENT); if (error) { @@ -1017,6 +1341,13 @@ netdev_dev_get_type(const struct netdev_dev *netdev_dev) return netdev_dev->netdev_class->type; } +/* Returns the class associated with 'netdev_dev'. */ +const struct netdev_class * +netdev_dev_get_class(const struct netdev_dev *netdev_dev) +{ + return netdev_dev->netdev_class; +} + /* Returns the name of 'netdev_dev'. * * The caller must not free the returned value. */ @@ -1088,7 +1419,7 @@ netdev_uninit(struct netdev *netdev, bool close) } -/* Returns the class type of 'netdev'. +/* Returns the class type of 'netdev'. * * The caller must not free the returned value. */ const char * @@ -1155,9 +1486,7 @@ netdev_monitor_cb(struct netdev_notifier *notifier) { struct netdev_monitor *monitor = notifier->aux; const char *name = netdev_get_name(notifier->netdev); - if (!shash_find(&monitor->changed_netdevs, name)) { - shash_add(&monitor->changed_netdevs, name, NULL); - } + shash_add_once(&monitor->changed_netdevs, name, NULL); } /* Attempts to add 'netdev' as a netdev monitored by 'monitor'. Returns 0 if