mirror of
https://github.com/torvalds/linux
synced 2024-10-21 18:59:26 +00:00
3ede8f72a9
In our application, we need a way to force TCP connections to go out a
specific IP interface instead of letting Linux select the interface
based on the routing tables.
Add the 'host-iface' option to allow specifying the interface to use.
When the option host-iface is specified, the driver uses the specified
interface to set the option SO_BINDTODEVICE on the TCP socket before
connecting.
This new option is needed in addtion to the existing host-traddr for
the following reasons:
Specifying an IP interface by its associated IP address is less
intuitive than specifying the actual interface name and, in some cases,
simply doesn't work. That's because the association between interfaces
and IP addresses is not predictable. IP addresses can be changed or can
change by themselves over time (e.g. DHCP). Interface names are
predictable [1] and will persist over time. Consider the following
configuration.
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state ...
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 100.0.0.100/24 scope global lo
valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:21:65:ec brd ff:ff:ff:ff:ff:ff
inet 100.0.0.100/24 scope global enp0s3
valid_lft forever preferred_lft forever
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:4f:95:5c brd ff:ff:ff:ff:ff:ff
inet 100.0.0.100/24 scope global enp0s8
valid_lft forever preferred_lft forever
The above is a VM that I configured with the same IP address
(100.0.0.100) on all interfaces. Doing a reverse lookup to identify the
unique interface associated with 100.0.0.100 does not work here. And
this is why the option host_iface is required. I understand that the
above config does not represent a standard host system, but I'm using
this to prove a point: "We can never know how users will configure
their systems". By te way, The above configuration is perfectly fine
by Linux.
The current TCP implementation for host_traddr performs a
bind()-before-connect(). This is a common construct to set the source
IP address on a TCP socket before connecting. This has no effect on how
Linux selects the interface for the connection. That's because Linux
uses the Weak End System model as described in RFC1122 [2]. On the other
hand, setting the Source IP Address has benefits and should be supported
by linux-nvme. In fact, setting the Source IP Address is a mandatory
FedGov requirement (e.g. connection to a RADIUS/TACACS+ server).
Consider the following configuration.
$ ip addr list dev enp0s8
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:4f:95:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.56.101/24 brd 192.168.56.255 scope global enp0s8
valid_lft 426sec preferred_lft 426sec
inet 192.168.56.102/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
inet 192.168.56.103/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
inet 192.168.56.104/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
Here we can see that several addresses are associated with interface
enp0s8. By default, Linux always selects the default IP address,
192.168.56.101, as the source address when connecting over interface
enp0s8. Some users, however, want the ability to specify a different
source address (e.g., 192.168.56.102, 192.168.56.103, ...). The option
host_traddr can be used as-is to perform this function.
In conclusion, I believe that we need 2 options for TCP connections.
One that can be used to specify an interface (host-iface). And one that
can be used to set the source address (host-traddr). Users should be
allowed to use one or the other, or both, or none. Of course, the
documentation for host_traddr will need some clarification. It should
state that when used for TCP connection, this option only sets the
source address. And the documentation for host_iface should say that
this option is only available for TCP connections.
References:
[1] https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
[2] https://tools.ietf.org/html/rfc1122
Tested both IPv4 and IPv6 connections.
Signed-off-by: Martin Belanger <martin.belanger@dell.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
195 lines
7 KiB
C
195 lines
7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* NVMe over Fabrics common host code.
|
|
* Copyright (c) 2015-2016 HGST, a Western Digital Company.
|
|
*/
|
|
#ifndef _NVME_FABRICS_H
|
|
#define _NVME_FABRICS_H 1
|
|
|
|
#include <linux/in.h>
|
|
#include <linux/inet.h>
|
|
|
|
#define NVMF_MIN_QUEUE_SIZE 16
|
|
#define NVMF_MAX_QUEUE_SIZE 1024
|
|
#define NVMF_DEF_QUEUE_SIZE 128
|
|
#define NVMF_DEF_RECONNECT_DELAY 10
|
|
/* default to 600 seconds of reconnect attempts before giving up */
|
|
#define NVMF_DEF_CTRL_LOSS_TMO 600
|
|
/* default is -1: the fail fast mechanism is disabled */
|
|
#define NVMF_DEF_FAIL_FAST_TMO -1
|
|
|
|
/*
|
|
* Reserved one command for internal usage. This command is used for sending
|
|
* the connect command, as well as for the keep alive command on the admin
|
|
* queue once live.
|
|
*/
|
|
#define NVMF_RESERVED_TAGS 1
|
|
|
|
/*
|
|
* Define a host as seen by the target. We allocate one at boot, but also
|
|
* allow the override it when creating controllers. This is both to provide
|
|
* persistence of the Host NQN over multiple boots, and to allow using
|
|
* multiple ones, for example in a container scenario. Because we must not
|
|
* use different Host NQNs with the same Host ID we generate a Host ID and
|
|
* use this structure to keep track of the relation between the two.
|
|
*/
|
|
struct nvmf_host {
|
|
struct kref ref;
|
|
struct list_head list;
|
|
char nqn[NVMF_NQN_SIZE];
|
|
uuid_t id;
|
|
};
|
|
|
|
/**
|
|
* enum nvmf_parsing_opts - used to define the sysfs parsing options used.
|
|
*/
|
|
enum {
|
|
NVMF_OPT_ERR = 0,
|
|
NVMF_OPT_TRANSPORT = 1 << 0,
|
|
NVMF_OPT_NQN = 1 << 1,
|
|
NVMF_OPT_TRADDR = 1 << 2,
|
|
NVMF_OPT_TRSVCID = 1 << 3,
|
|
NVMF_OPT_QUEUE_SIZE = 1 << 4,
|
|
NVMF_OPT_NR_IO_QUEUES = 1 << 5,
|
|
NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
|
|
NVMF_OPT_KATO = 1 << 7,
|
|
NVMF_OPT_HOSTNQN = 1 << 8,
|
|
NVMF_OPT_RECONNECT_DELAY = 1 << 9,
|
|
NVMF_OPT_HOST_TRADDR = 1 << 10,
|
|
NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
|
|
NVMF_OPT_HOST_ID = 1 << 12,
|
|
NVMF_OPT_DUP_CONNECT = 1 << 13,
|
|
NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
|
|
NVMF_OPT_HDR_DIGEST = 1 << 15,
|
|
NVMF_OPT_DATA_DIGEST = 1 << 16,
|
|
NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
|
|
NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
|
|
NVMF_OPT_TOS = 1 << 19,
|
|
NVMF_OPT_FAIL_FAST_TMO = 1 << 20,
|
|
NVMF_OPT_HOST_IFACE = 1 << 21,
|
|
};
|
|
|
|
/**
|
|
* struct nvmf_ctrl_options - Used to hold the options specified
|
|
* with the parsing opts enum.
|
|
* @mask: Used by the fabrics library to parse through sysfs options
|
|
* on adding a NVMe controller.
|
|
* @transport: Holds the fabric transport "technology name" (for a lack of
|
|
* better description) that will be used by an NVMe controller
|
|
* being added.
|
|
* @subsysnqn: Hold the fully qualified NQN subystem name (format defined
|
|
* in the NVMe specification, "NVMe Qualified Names").
|
|
* @traddr: The transport-specific TRADDR field for a port on the
|
|
* subsystem which is adding a controller.
|
|
* @trsvcid: The transport-specific TRSVCID field for a port on the
|
|
* subsystem which is adding a controller.
|
|
* @host_traddr: A transport-specific field identifying the NVME host port
|
|
* to use for the connection to the controller.
|
|
* @host_iface: A transport-specific field identifying the NVME host
|
|
* interface to use for the connection to the controller.
|
|
* @queue_size: Number of IO queue elements.
|
|
* @nr_io_queues: Number of controller IO queues that will be established.
|
|
* @reconnect_delay: Time between two consecutive reconnect attempts.
|
|
* @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
|
|
* @kato: Keep-alive timeout.
|
|
* @host: Virtual NVMe host, contains the NQN and Host ID.
|
|
* @max_reconnects: maximum number of allowed reconnect attempts before removing
|
|
* the controller, (-1) means reconnect forever, zero means remove
|
|
* immediately;
|
|
* @disable_sqflow: disable controller sq flow control
|
|
* @hdr_digest: generate/verify header digest (TCP)
|
|
* @data_digest: generate/verify data digest (TCP)
|
|
* @nr_write_queues: number of queues for write I/O
|
|
* @nr_poll_queues: number of queues for polling I/O
|
|
* @tos: type of service
|
|
* @fast_io_fail_tmo: Fast I/O fail timeout in seconds
|
|
*/
|
|
struct nvmf_ctrl_options {
|
|
unsigned mask;
|
|
char *transport;
|
|
char *subsysnqn;
|
|
char *traddr;
|
|
char *trsvcid;
|
|
char *host_traddr;
|
|
char *host_iface;
|
|
size_t queue_size;
|
|
unsigned int nr_io_queues;
|
|
unsigned int reconnect_delay;
|
|
bool discovery_nqn;
|
|
bool duplicate_connect;
|
|
unsigned int kato;
|
|
struct nvmf_host *host;
|
|
int max_reconnects;
|
|
bool disable_sqflow;
|
|
bool hdr_digest;
|
|
bool data_digest;
|
|
unsigned int nr_write_queues;
|
|
unsigned int nr_poll_queues;
|
|
int tos;
|
|
int fast_io_fail_tmo;
|
|
};
|
|
|
|
/*
|
|
* struct nvmf_transport_ops - used to register a specific
|
|
* fabric implementation of NVMe fabrics.
|
|
* @entry: Used by the fabrics library to add the new
|
|
* registration entry to its linked-list internal tree.
|
|
* @module: Transport module reference
|
|
* @name: Name of the NVMe fabric driver implementation.
|
|
* @required_opts: sysfs command-line options that must be specified
|
|
* when adding a new NVMe controller.
|
|
* @allowed_opts: sysfs command-line options that can be specified
|
|
* when adding a new NVMe controller.
|
|
* @create_ctrl(): function pointer that points to a non-NVMe
|
|
* implementation-specific fabric technology
|
|
* that would go into starting up that fabric
|
|
* for the purpose of conneciton to an NVMe controller
|
|
* using that fabric technology.
|
|
*
|
|
* Notes:
|
|
* 1. At minimum, 'required_opts' and 'allowed_opts' should
|
|
* be set to the same enum parsing options defined earlier.
|
|
* 2. create_ctrl() must be defined (even if it does nothing)
|
|
* 3. struct nvmf_transport_ops must be statically allocated in the
|
|
* modules .bss section so that a pure module_get on @module
|
|
* prevents the memory from beeing freed.
|
|
*/
|
|
struct nvmf_transport_ops {
|
|
struct list_head entry;
|
|
struct module *module;
|
|
const char *name;
|
|
int required_opts;
|
|
int allowed_opts;
|
|
struct nvme_ctrl *(*create_ctrl)(struct device *dev,
|
|
struct nvmf_ctrl_options *opts);
|
|
};
|
|
|
|
static inline bool
|
|
nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
|
|
struct nvmf_ctrl_options *opts)
|
|
{
|
|
if (ctrl->state == NVME_CTRL_DELETING ||
|
|
ctrl->state == NVME_CTRL_DEAD ||
|
|
strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
|
|
strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
|
|
memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
|
|
int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
|
|
int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
|
|
int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
|
|
int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
|
|
int nvmf_register_transport(struct nvmf_transport_ops *ops);
|
|
void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
|
|
void nvmf_free_options(struct nvmf_ctrl_options *opts);
|
|
int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
|
|
bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
|
|
bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
|
|
struct nvmf_ctrl_options *opts);
|
|
|
|
#endif /* _NVME_FABRICS_H */
|