diff options
Diffstat (limited to 'flow.h')
| -rw-r--r-- | flow.h | 81 |
1 files changed, 76 insertions, 5 deletions
@@ -10,6 +10,68 @@ #define FLOW_TIMER_INTERVAL 1000 /* ms */ /** + * enum flow_state - States of a flow table entry + * + * An individual flow table entry moves through these states, usually in this + * order. + * General rules: + * - Code outside flow.c should never write common fields of union flow. + * - The state field may always be read. + * + * FREE - Part of the general pool of free flow table entries + * Operations: + * - flow_alloc() finds an entry and moves it to NEW + * + * NEW - Freshly allocated, uninitialised entry + * Operations: + * - flow_alloc_cancel() returns the entry to FREE + * - FLOW_SET_TYPE() sets the entry's type and moves to TYPED + * Caveats: + * - No fields other than state may be accessed + * - At most one entry may be NEW or TYPED at a time, so it's unsafe + * to use flow_alloc() again until this entry moves to ACTIVE or + * FREE + * - You may not return to the main epoll loop while any flow is NEW + * + * TYPED - Generic info initialised, type specific initialisation underway + * Operations: + * - All common fields may be read + * - Type specific fields may be read and written + * - flow_alloc_cancel() returns the entry to FREE + * - FLOW_ACTIVATE() moves the entry to ACTIVE + * Caveats: + * - At most one entry may be NEW or TYPED at a time, so it's unsafe + * to use flow_alloc() again until this entry moves to ACTIVE or + * FREE + * - You may not return to the main epoll loop while any flow is + * TYPED + * + * ACTIVE - An active, fully-initialised flow entry + * Operations: + * - All common fields may be read + * - Type specific fields may be read and written + * - Flow returns to FREE when it expires, signalled by returning + * 'true' from flow type specific deferred or timer handler + * Caveats: + * - flow_alloc_cancel() may not be called on it + */ +enum flow_state { + FLOW_STATE_FREE, + FLOW_STATE_NEW, + FLOW_STATE_TYPED, + FLOW_STATE_ACTIVE, + + FLOW_NUM_STATES, +}; +#define FLOW_STATE_BITS 8 +static_assert(FLOW_NUM_STATES <= (1 << FLOW_STATE_BITS), + "Too many flow states for FLOW_STATE_BITS"); + +extern const char *flow_state_str[]; +#define FLOW_STATE(f) \ + ((f)->state < FLOW_NUM_STATES ? flow_state_str[(f)->state] : "?") + +/** * enum flow_type - Different types of packet flows we track */ enum flow_type { @@ -26,6 +88,9 @@ enum flow_type { FLOW_NUM_TYPES, }; +#define FLOW_TYPE_BITS 8 +static_assert(FLOW_NUM_TYPES <= (1 << FLOW_TYPE_BITS), + "Too many flow types for FLOW_TYPE_BITS"); extern const char *flow_type_str[]; #define FLOW_TYPE(f) \ @@ -37,10 +102,21 @@ extern const uint8_t flow_proto[]; /** * struct flow_common - Common fields for packet flows + * @state: State of the flow table entry * @type: Type of packet flow */ struct flow_common { +#ifdef __GNUC__ + enum flow_state state:FLOW_STATE_BITS; + enum flow_type type:FLOW_TYPE_BITS; +#else + uint8_t state; + static_assert(sizeof(uint8_t) * 8 >= FLOW_STATE_BITS, + "Not enough bits for state field"); uint8_t type; + static_assert(sizeof(uint8_t) * 8 >= FLOW_TYPE_BITS, + "Not enough bits for type field"); +#endif }; #define FLOW_INDEX_BITS 17 /* 128k - 1 */ @@ -49,11 +125,6 @@ struct flow_common { #define FLOW_TABLE_PRESSURE 30 /* % of FLOW_MAX */ #define FLOW_FILE_PRESSURE 30 /* % of c->nofile */ -union flow *flow_start(union flow *flow, enum flow_type type, - unsigned iniside); -#define FLOW_START(flow_, t_, var_, i_) \ - (&flow_start((flow_), (t_), (i_))->var_) - /** * struct flow_sidx - ID for one side of a specific flow * @side: Side referenced (0 or 1) |