From 3310b5708bfb066986de399aa27d922763a1cb2c Mon Sep 17 00:00:00 2001 From: Justin Pettit Date: Fri, 14 Oct 2011 09:48:43 -0700 Subject: [PATCH] Various bug fixes and cleanups to STP library. - Don't apply endian conversions to flags, which are 8 bits. - Use #defines for default times for use outside library. - Clarify our behavior when in STP_DISABLED state. - Add "aux" member to STP port struct to be able to refer back to the owning port. - Define macros to print STP bridge and port ids. - New helper function to get port id. - New helper function to convert speed to cost. - New functions to describe current role of port. --- lib/stp.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++-------- lib/stp.h | 52 +++++++++++++++++++++++++++-- 2 files changed, 135 insertions(+), 16 deletions(-) diff --git a/lib/stp.c b/lib/stp.c index edd37b32..94b9a4b5 100644 --- a/lib/stp.c +++ b/lib/stp.c @@ -77,6 +77,7 @@ struct stp_timer { struct stp_port { struct stp *stp; + void *aux; /* Auxiliary data the user may retrieve. */ int port_id; /* 8.5.5.1: Unique port identifier. */ enum stp_state state; /* 8.5.5.2: Current state. */ int path_cost; /* 8.5.5.3: Cost of tx/rx on this port. */ @@ -223,9 +224,9 @@ stp_create(const char *name, stp_identifier bridge_id, stp->bridge_id |= (uint64_t) STP_DEFAULT_BRIDGE_PRIORITY << 48; } - stp->rq_max_age = 6000; - stp->rq_hello_time = 2000; - stp->rq_forward_delay = 4000; + stp->rq_max_age = STP_DEFAULT_MAX_AGE; + stp->rq_hello_time = STP_DEFAULT_HELLO_TIME; + stp->rq_forward_delay = STP_DEFAULT_FWD_DELAY; stp_update_bridge_timers(stp); stp->max_age = stp->bridge_max_age; stp->hello_time = stp->bridge_hello_time; @@ -526,6 +527,25 @@ stp_learn_in_state(enum stp_state state) return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0; } +/* Returns the name for the given 'role' (for use in debugging and log + * messages). */ +const char * +stp_role_name(enum stp_role role) +{ + switch (role) { + case STP_ROLE_ROOT: + return "root"; + case STP_ROLE_DESIGNATED: + return "designated"; + case STP_ROLE_ALTERNATE: + return "alternate"; + case STP_ROLE_DISABLED: + return "disabled"; + default: + NOT_REACHED(); + } +} + /* Notifies the STP entity that bridge protocol data unit 'bpdu', which is * 'bpdu_size' bytes in length, was received on port 'p'. * @@ -589,6 +609,24 @@ stp_port_get_stp(struct stp_port *p) return p->stp; } +/* Sets the 'aux' member of 'p'. + * + * The 'aux' member will be reset to NULL when stp_port_disable() is + * called or stp_port_enable() is called when the port is in a Disabled + * state. */ +void +stp_port_set_aux(struct stp_port *p, void *aux) +{ + p->aux = aux; +} + +/* Returns the 'aux' member of 'p'. */ +void * +stp_port_get_aux(struct stp_port *p) +{ + return p->aux; +} + /* Returns the index of port 'p' within its bridge. */ int stp_port_no(const struct stp_port *p) @@ -598,6 +636,13 @@ stp_port_no(const struct stp_port *p) return p - stp->ports; } +/* Returns the port ID for 'p'. */ +int +stp_port_get_id(const struct stp_port *p) +{ + return p->port_id; +} + /* Returns the state of port 'p'. */ enum stp_state stp_port_get_state(const struct stp_port *p) @@ -605,6 +650,23 @@ stp_port_get_state(const struct stp_port *p) return p->state; } +/* Returns the role of port 'p'. */ +enum stp_role +stp_port_get_role(const struct stp_port *p) +{ + struct stp_port *root_port = stp_get_root_port(p->stp); + + if (root_port && root_port->port_id == p->port_id) { + return STP_ROLE_ROOT; + } else if (stp_is_designated_port(p)) { + return STP_ROLE_DESIGNATED; + } else if (p->state == STP_DISABLED) { + return STP_ROLE_DISABLED; + } else { + return STP_ROLE_ALTERNATE; + } +} + /* Disables STP on port 'p'. */ void stp_port_disable(struct stp_port *p) @@ -623,6 +685,7 @@ stp_port_disable(struct stp_port *p) if (stp_is_root_bridge(stp) && !root) { stp_become_root_bridge(stp); } + p->aux = NULL; } } @@ -656,6 +719,19 @@ stp_port_set_priority(struct stp_port *p, uint8_t new_priority) } } +/* Convert 'speed' (measured in Mb/s) into the path cost. */ +uint16_t +stp_convert_speed_to_cost(unsigned int speed) +{ + return speed >= 10000 ? 2 /* 10 Gb/s. */ + : speed >= 1000 ? 4 /* 1 Gb/s. */ + : speed >= 100 ? 19 /* 100 Mb/s. */ + : speed >= 16 ? 62 /* 16 Mb/s. */ + : speed >= 10 ? 100 /* 10 Mb/s. */ + : speed >= 4 ? 250 /* 4 Mb/s. */ + : 19; /* 100 Mb/s (guess). */ +} + /* Sets the path cost of port 'p' to 'path_cost'. Lower values are generally * used to indicate faster links. Use stp_port_set_speed() to automatically * generate a default path cost from a link speed. */ @@ -674,13 +750,7 @@ stp_port_set_path_cost(struct stp_port *p, uint16_t path_cost) void stp_port_set_speed(struct stp_port *p, unsigned int speed) { - stp_port_set_path_cost(p, (speed >= 10000 ? 2 /* 10 Gb/s. */ - : speed >= 1000 ? 4 /* 1 Gb/s. */ - : speed >= 100 ? 19 /* 100 Mb/s. */ - : speed >= 16 ? 62 /* 16 Mb/s. */ - : speed >= 10 ? 100 /* 10 Mb/s. */ - : speed >= 4 ? 250 /* 4 Mb/s. */ - : 19)); /* 100 Mb/s (guess). */ + stp_port_set_path_cost(p, stp_convert_speed_to_cost(speed)); } /* Enables topology change detection on port 'p'. */ @@ -715,10 +785,10 @@ stp_transmit_config(struct stp_port *p) config.header.bpdu_type = STP_TYPE_CONFIG; config.flags = 0; if (p->topology_change_ack) { - config.flags |= htons(STP_CONFIG_TOPOLOGY_CHANGE_ACK); + config.flags |= STP_CONFIG_TOPOLOGY_CHANGE_ACK; } if (stp->topology_change) { - config.flags |= htons(STP_CONFIG_TOPOLOGY_CHANGE); + config.flags |= STP_CONFIG_TOPOLOGY_CHANGE; } config.root_id = htonll(stp->designated_root); config.root_path_cost = htonl(stp->root_path_cost); @@ -776,7 +846,7 @@ stp_record_config_timeout_values(struct stp *stp, stp->max_age = ntohs(config->max_age); stp->hello_time = ntohs(config->hello_time); stp->forward_delay = ntohs(config->forward_delay); - stp->topology_change = config->flags & htons(STP_CONFIG_TOPOLOGY_CHANGE); + stp->topology_change = config->flags & STP_CONFIG_TOPOLOGY_CHANGE; } static bool @@ -1004,7 +1074,7 @@ stp_received_config_bpdu(struct stp *stp, struct stp_port *p, if (p == stp->root_port) { stp_record_config_timeout_values(stp, config); stp_config_bpdu_generation(stp); - if (config->flags & htons(STP_CONFIG_TOPOLOGY_CHANGE_ACK)) { + if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE_ACK) { stp_topology_change_acknowledged(stp); } } @@ -1111,6 +1181,7 @@ stp_initialize_port(struct stp_port *p, enum stp_state state) p->topology_change_ack = false; p->config_pending = false; p->change_detection_enabled = true; + p->aux = NULL; stp_stop_timer(&p->message_age_timer); stp_stop_timer(&p->forward_delay_timer); stp_stop_timer(&p->hold_timer); diff --git a/lib/stp.h b/lib/stp.h index 7eb2cb96..54f7f5b4 100644 --- a/lib/stp.h +++ b/lib/stp.h @@ -36,10 +36,23 @@ struct ofpbuf; #define STP_DEFAULT_BRIDGE_PRIORITY 32768 #define STP_DEFAULT_PORT_PRIORITY 128 +/* Default time values. */ +#define STP_DEFAULT_MAX_AGE 20000 +#define STP_DEFAULT_HELLO_TIME 2000 +#define STP_DEFAULT_FWD_DELAY 15000 + /* Bridge identifier. Top 16 bits are a priority value (numerically lower * values are higher priorities). Bottom 48 bits are MAC address of bridge. */ typedef uint64_t stp_identifier; + +#define STP_ID_FMT "%04"PRIx16".%012"PRIx64 +#define STP_ID_ARGS(stp_id) \ + (uint16_t)((stp_id) >> 48), \ + (uint64_t)((stp_id) & 0xffffffffffffULL) + +#define STP_PORT_ID_FMT "%04"PRIx16 + /* Basic STP functionality. */ #define STP_MAX_PORTS 255 struct stp *stp_create(const char *name, stp_identifier bridge_id, @@ -72,9 +85,30 @@ bool stp_get_changed_port(struct stp *, struct stp_port **portp); /* State of an STP port. * * A port is in exactly one state at any given time, but distinct bits are used - * for states to allow testing for more than one state with a bit mask. */ + * for states to allow testing for more than one state with a bit mask. + * + * The STP_DISABLED state means that the port is disabled by management. + * In our implementation, this state means that the port does not + * participate in the spanning tree, but it still forwards traffic as if + * it were in the STP_FORWARDING state. This may be different from + * other implementations. + * + * The following diagram describes the various states and what they are + * allowed to do in OVS: + * + * FWD LRN TX_BPDU RX_BPDU + * --- --- ------- ------- + * Disabled Y - - - + * Blocking - - - Y + * Listening - - Y Y + * Learning - Y Y Y + * Forwarding Y Y Y Y + * + * Once again, note that the disabled state forwards traffic, which is + * likely different than the spec would indicate. + */ enum stp_state { - STP_DISABLED = 1 << 0, /* 8.4.5: Disabled by management. */ + STP_DISABLED = 1 << 0, /* 8.4.5: See note above. */ STP_LISTENING = 1 << 1, /* 8.4.2: Not learning or relaying frames. */ STP_LEARNING = 1 << 2, /* 8.4.3: Learning but not relaying frames. */ STP_FORWARDING = 1 << 3, /* 8.4.4: Learning and relaying frames. */ @@ -84,14 +118,28 @@ const char *stp_state_name(enum stp_state); bool stp_forward_in_state(enum stp_state); bool stp_learn_in_state(enum stp_state); +/* Role of an STP port. */ +enum stp_role { + STP_ROLE_ROOT, /* Path to root bridge. */ + STP_ROLE_DESIGNATED, /* Path to LAN segments. */ + STP_ROLE_ALTERNATE, /* Backup path to root bridge. */ + STP_ROLE_DISABLED /* Port does not participate in STP. */ +}; +const char *stp_role_name(enum stp_role); + void stp_received_bpdu(struct stp_port *, const void *bpdu, size_t bpdu_size); struct stp *stp_port_get_stp(struct stp_port *); +void stp_port_set_aux(struct stp_port *, void *); +void *stp_port_get_aux(struct stp_port *); int stp_port_no(const struct stp_port *); +int stp_port_get_id(const struct stp_port *); enum stp_state stp_port_get_state(const struct stp_port *); +enum stp_role stp_port_get_role(const struct stp_port *); void stp_port_enable(struct stp_port *); void stp_port_disable(struct stp_port *); void stp_port_set_priority(struct stp_port *, uint8_t new_priority); +uint16_t stp_convert_speed_to_cost(unsigned int speed); void stp_port_set_path_cost(struct stp_port *, uint16_t path_cost); void stp_port_set_speed(struct stp_port *, unsigned int speed); void stp_port_enable_change_detection(struct stp_port *); -- 2.30.2