/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2007-2009 Robert N. M. Watson
* Copyright (c) 2010-2011 Juniper Networks, Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson under contract
* to Juniper Networks, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _NET_NETISR_H_
#define _NET_NETISR_H_
/*
* The netisr (network interrupt service routine) provides a deferred
* execution evironment in which (generally inbound) network processing can
* take place. Protocols register handlers which will be executed directly,
* or via deferred dispatch, depending on the circumstances.
*
* Historically, this was implemented by the BSD software ISR facility; it is
* now implemented via a software ithread (SWI).
*/
/*
* Protocol numbers, which are encoded in monitoring applications and kernel
* modules. Internally, these are used in bit shift operations so must have
* a value 0 < proto < 32; we currently further limit at compile-time to 16
* for array-sizing purposes.
*/
#define NETISR_IP 1
#define NETISR_IGMP 2 /* IGMPv3 output queue */
#define NETISR_ROUTE 3 /* routing socket */
#define NETISR_ARP 4 /* same as AF_LINK */
#define NETISR_ETHER 5 /* ethernet input */
#define NETISR_IPV6 6
#define NETISR_IP_DIRECT 9 /* direct-dispatch IPv4 */
#define NETISR_IPV6_DIRECT 10 /* direct-dispatch IPv6 */
/*
* Protocol ordering and affinity policy constants. See the detailed
* discussion of policies later in the file.
*/
#define NETISR_POLICY_SOURCE 1 /* Maintain source ordering. */
#define NETISR_POLICY_FLOW 2 /* Maintain flow ordering. */
#define NETISR_POLICY_CPU 3 /* Protocol determines CPU placement. */
/*
* Protocol dispatch policy constants; selects whether and when direct
* dispatch is permitted.
*/
#define NETISR_DISPATCH_DEFAULT 0 /* Use global default. */
#define NETISR_DISPATCH_DEFERRED 1 /* Always defer dispatch. */
#define NETISR_DISPATCH_HYBRID 2 /* Allow hybrid dispatch. */
#define NETISR_DISPATCH_DIRECT 3 /* Always direct dispatch. */
/*
* Monitoring data structures, exported by sysctl(2).
*
* Three sysctls are defined. First, a per-protocol structure exported by
* net.isr.proto.
*/
#define NETISR_NAMEMAXLEN 32
struct sysctl_netisr_proto {
u_int snp_version; /* Length of struct. */
char snp_name[NETISR_NAMEMAXLEN]; /* nh_name */
u_int snp_proto; /* nh_proto */
u_int snp_qlimit; /* nh_qlimit */
u_int snp_policy; /* nh_policy */
u_int snp_flags; /* Various flags. */
u_int snp_dispatch; /* Dispatch policy. */
u_int _snp_ispare[6];
};
/*
* Flags for sysctl_netisr_proto.snp_flags.
*/
#define NETISR_SNP_FLAGS_M2FLOW 0x00000001 /* nh_m2flow */
#define NETISR_SNP_FLAGS_M2CPUID 0x00000002 /* nh_m2cpuid */
#define NETISR_SNP_FLAGS_DRAINEDCPU 0x00000004 /* nh_drainedcpu */
/*
* Next, a structure per-workstream, with per-protocol data, exported as
* net.isr.workstream.
*/
struct sysctl_netisr_workstream {
u_int snws_version; /* Length of struct. */
u_int snws_flags; /* Various flags. */
u_int snws_wsid; /* Workstream ID. */
u_int snws_cpu; /* nws_cpu */
u_int _snws_ispare[12];
};
/*
* Flags for sysctl_netisr_workstream.snws_flags
*/
#define NETISR_SNWS_FLAGS_INTR 0x00000001 /* nws_intr_event */
/*
* Finally, a per-workstream-per-protocol structure, exported as
* net.isr.work.
*/
struct sysctl_netisr_work {
u_int snw_version; /* Length of struct. */
u_int snw_wsid; /* Workstream ID. */
u_int snw_proto; /* Protocol number. */
u_int snw_len; /* nw_len */
u_int snw_watermark; /* nw_watermark */
u_int _snw_ispare[3];
uint64_t snw_dispatched; /* nw_dispatched */
uint64_t snw_hybrid_dispatched; /* nw_hybrid_dispatched */
uint64_t snw_qdrops; /* nw_qdrops */
uint64_t snw_queued; /* nw_queued */
uint64_t snw_handled; /* nw_handled */
uint64_t _snw_llspare[7];
};
#ifdef _KERNEL
/*-
* Protocols express ordering constraints and affinity preferences by
* implementing one or neither of nh_m2flow and nh_m2cpuid, which are used by
* netisr to determine which per-CPU workstream to assign mbufs to.
*
* The following policies may be used by protocols:
*
* NETISR_POLICY_SOURCE - netisr should maintain source ordering without
* advice from the protocol. netisr will ignore any
* flow IDs present on the mbuf for the purposes of
* work placement.
*
* NETISR_POLICY_FLOW - netisr should maintain flow ordering as defined by
* the mbuf header flow ID field. If the protocol
* implements nh_m2flow, then netisr will query the
* protocol in the event that the mbuf doesn't have a
* flow ID, falling back on source ordering.
*
* NETISR_POLICY_CPU - netisr will delegate all work placement decisions to
* the protocol, querying nh_m2cpuid for each packet.
*
* Protocols might make decisions about work placement based on an existing
* calculated flow ID on the mbuf, such as one provided in hardware, the
* receive interface pointed to by the mbuf (if any), the optional source
* identifier passed at some dispatch points, or even parse packet headers to
* calculate a flow. Both protocol handlers may return a new mbuf pointer
* for the chain, or NULL if the packet proves invalid or m_pullup() fails.
*
* XXXRW: If we eventually support dynamic reconfiguration, there should be
* protocol handlers to notify them of CPU configuration changes so that they
* can rebalance work.
*/
struct mbuf;
typedef void netisr_handler_t(struct mbuf *m);
typedef struct mbuf *netisr_m2cpuid_t(struct mbuf *m, uintptr_t source,
u_int *cpuid);
typedef struct mbuf *netisr_m2flow_t(struct mbuf *m, uintptr_t source);
typedef void netisr_drainedcpu_t(u_int cpuid);
#define NETISR_CPUID_NONE ((u_int)-1) /* No affinity returned. */
/*
* Data structure describing a protocol handler.
*/
struct netisr_handler {
const char *nh_name; /* Character string protocol name. */
netisr_handler_t *nh_handler; /* Protocol handler. */
netisr_m2flow_t *nh_m2flow; /* Query flow for untagged packet. */
netisr_m2cpuid_t *nh_m2cpuid; /* Query CPU to process mbuf on. */
netisr_drainedcpu_t *nh_drainedcpu; /* Callback when drained a queue. */
u_int nh_proto; /* Integer protocol ID. */
u_int nh_qlimit; /* Maximum per-CPU queue depth. */
u_int nh_policy; /* Work placement policy. */
u_int nh_dispatch; /* Dispatch policy. */
u_int nh_ispare[4]; /* For future use. */
void *nh_pspare[4]; /* For future use. */
};
/*
* Register, unregister, and other netisr handler management functions.
*/
void netisr_clearqdrops(const struct netisr_handler *nhp);
void netisr_getqdrops(const struct netisr_handler *nhp,
u_int64_t *qdropsp);
void netisr_getqlimit(const struct netisr_handler *nhp, u_int *qlimitp);
void netisr_register(const struct netisr_handler *nhp);
int netisr_setqlimit(const struct netisr_handler *nhp, u_int qlimit);
void netisr_unregister(const struct netisr_handler *nhp);
#ifdef VIMAGE
void netisr_register_vnet(const struct netisr_handler *nhp);
void netisr_unregister_vnet(const struct netisr_handler *nhp);
#endif
/*
* Process a packet destined for a protocol, and attempt direct dispatch.
* Supplemental source ordering information can be passed using the _src
* variant.
*/
int netisr_dispatch(u_int proto, struct mbuf *m);
int netisr_dispatch_src(u_int proto, uintptr_t source, struct mbuf *m);
int netisr_queue(u_int proto, struct mbuf *m);
int netisr_queue_src(u_int proto, uintptr_t source, struct mbuf *m);
/*
* Provide a default implementation of "map an ID to a CPU ID".
*/
u_int netisr_default_flow2cpu(u_int flowid);
/*
* Utility routines to return the number of CPUs participting in netisr, and
* to return a mapping from a number to a CPU ID that can be used with the
* scheduler.
*/
u_int netisr_get_cpucount(void);
u_int netisr_get_cpuid(u_int cpunumber);
/*
* Interfaces between DEVICE_POLLING and netisr.
*/
void netisr_sched_poll(void);
void netisr_poll(void);
void netisr_pollmore(void);
#endif /* !_KERNEL */
#endif /* !_NET_NETISR_H_ */
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