alistair23-linux/net/sctp/sysctl.c
Christoph Hellwig 32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00

522 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2002, 2004
* Copyright (c) 2002 Intel Corp.
*
* This file is part of the SCTP kernel implementation
*
* Sysctl related interfaces for SCTP.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* Mingqin Liu <liuming@us.ibm.com>
* Jon Grimm <jgrimm@us.ibm.com>
* Ardelle Fan <ardelle.fan@intel.com>
* Ryan Layer <rmlayer@us.ibm.com>
* Sridhar Samudrala <sri@us.ibm.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <net/sctp/structs.h>
#include <net/sctp/sctp.h>
#include <linux/sysctl.h>
static int timer_max = 86400000; /* ms in one day */
static int sack_timer_min = 1;
static int sack_timer_max = 500;
static int addr_scope_max = SCTP_SCOPE_POLICY_MAX;
static int rwnd_scale_max = 16;
static int rto_alpha_min = 0;
static int rto_beta_min = 0;
static int rto_alpha_max = 1000;
static int rto_beta_max = 1000;
static int pf_expose_max = SCTP_PF_EXPOSE_MAX;
static int ps_retrans_max = SCTP_PS_RETRANS_MAX;
static unsigned long max_autoclose_min = 0;
static unsigned long max_autoclose_max =
(MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)
? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos);
static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos);
static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write, void *buffer,
size_t *lenp, loff_t *ppos);
static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos);
static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos);
static struct ctl_table sctp_table[] = {
{
.procname = "sctp_mem",
.data = &sysctl_sctp_mem,
.maxlen = sizeof(sysctl_sctp_mem),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax
},
{
.procname = "sctp_rmem",
.data = &sysctl_sctp_rmem,
.maxlen = sizeof(sysctl_sctp_rmem),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "sctp_wmem",
.data = &sysctl_sctp_wmem,
.maxlen = sizeof(sysctl_sctp_wmem),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ /* sentinel */ }
};
static struct ctl_table sctp_net_table[] = {
{
.procname = "rto_initial",
.data = &init_net.sctp.rto_initial,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &timer_max
},
{
.procname = "rto_min",
.data = &init_net.sctp.rto_min,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_sctp_do_rto_min,
.extra1 = SYSCTL_ONE,
.extra2 = &init_net.sctp.rto_max
},
{
.procname = "rto_max",
.data = &init_net.sctp.rto_max,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_sctp_do_rto_max,
.extra1 = &init_net.sctp.rto_min,
.extra2 = &timer_max
},
{
.procname = "rto_alpha_exp_divisor",
.data = &init_net.sctp.rto_alpha,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_sctp_do_alpha_beta,
.extra1 = &rto_alpha_min,
.extra2 = &rto_alpha_max,
},
{
.procname = "rto_beta_exp_divisor",
.data = &init_net.sctp.rto_beta,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_sctp_do_alpha_beta,
.extra1 = &rto_beta_min,
.extra2 = &rto_beta_max,
},
{
.procname = "max_burst",
.data = &init_net.sctp.max_burst,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "cookie_preserve_enable",
.data = &init_net.sctp.cookie_preserve_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "cookie_hmac_alg",
.data = &init_net.sctp.sctp_hmac_alg,
.maxlen = 8,
.mode = 0644,
.proc_handler = proc_sctp_do_hmac_alg,
},
{
.procname = "valid_cookie_life",
.data = &init_net.sctp.valid_cookie_life,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &timer_max
},
{
.procname = "sack_timeout",
.data = &init_net.sctp.sack_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &sack_timer_min,
.extra2 = &sack_timer_max,
},
{
.procname = "hb_interval",
.data = &init_net.sctp.hb_interval,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &timer_max
},
{
.procname = "association_max_retrans",
.data = &init_net.sctp.max_retrans_association,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "path_max_retrans",
.data = &init_net.sctp.max_retrans_path,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "max_init_retransmits",
.data = &init_net.sctp.max_retrans_init,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "pf_retrans",
.data = &init_net.sctp.pf_retrans,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &init_net.sctp.ps_retrans,
},
{
.procname = "ps_retrans",
.data = &init_net.sctp.ps_retrans,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &init_net.sctp.pf_retrans,
.extra2 = &ps_retrans_max,
},
{
.procname = "sndbuf_policy",
.data = &init_net.sctp.sndbuf_policy,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "rcvbuf_policy",
.data = &init_net.sctp.rcvbuf_policy,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "default_auto_asconf",
.data = &init_net.sctp.default_auto_asconf,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "addip_enable",
.data = &init_net.sctp.addip_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "addip_noauth_enable",
.data = &init_net.sctp.addip_noauth,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "prsctp_enable",
.data = &init_net.sctp.prsctp_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "reconf_enable",
.data = &init_net.sctp.reconf_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "auth_enable",
.data = &init_net.sctp.auth_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_sctp_do_auth,
},
{
.procname = "intl_enable",
.data = &init_net.sctp.intl_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "ecn_enable",
.data = &init_net.sctp.ecn_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "addr_scope_policy",
.data = &init_net.sctp.scope_policy,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &addr_scope_max,
},
{
.procname = "rwnd_update_shift",
.data = &init_net.sctp.rwnd_upd_shift,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &rwnd_scale_max,
},
{
.procname = "max_autoclose",
.data = &init_net.sctp.max_autoclose,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
.extra1 = &max_autoclose_min,
.extra2 = &max_autoclose_max,
},
{
.procname = "pf_enable",
.data = &init_net.sctp.pf_enable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "pf_expose",
.data = &init_net.sctp.pf_expose,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &pf_expose_max,
},
{ /* sentinel */ }
};
static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
struct ctl_table tbl;
bool changed = false;
char *none = "none";
char tmp[8] = {0};
int ret;
memset(&tbl, 0, sizeof(struct ctl_table));
if (write) {
tbl.data = tmp;
tbl.maxlen = sizeof(tmp);
} else {
tbl.data = net->sctp.sctp_hmac_alg ? : none;
tbl.maxlen = strlen(tbl.data);
}
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
#ifdef CONFIG_CRYPTO_MD5
if (!strncmp(tmp, "md5", 3)) {
net->sctp.sctp_hmac_alg = "md5";
changed = true;
}
#endif
#ifdef CONFIG_CRYPTO_SHA1
if (!strncmp(tmp, "sha1", 4)) {
net->sctp.sctp_hmac_alg = "sha1";
changed = true;
}
#endif
if (!strncmp(tmp, "none", 4)) {
net->sctp.sctp_hmac_alg = NULL;
changed = true;
}
if (!changed)
ret = -EINVAL;
}
return ret;
}
static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
unsigned int min = *(unsigned int *) ctl->extra1;
unsigned int max = *(unsigned int *) ctl->extra2;
struct ctl_table tbl;
int ret, new_value;
memset(&tbl, 0, sizeof(struct ctl_table));
tbl.maxlen = sizeof(unsigned int);
if (write)
tbl.data = &new_value;
else
tbl.data = &net->sctp.rto_min;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
if (new_value > max || new_value < min)
return -EINVAL;
net->sctp.rto_min = new_value;
}
return ret;
}
static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
unsigned int min = *(unsigned int *) ctl->extra1;
unsigned int max = *(unsigned int *) ctl->extra2;
struct ctl_table tbl;
int ret, new_value;
memset(&tbl, 0, sizeof(struct ctl_table));
tbl.maxlen = sizeof(unsigned int);
if (write)
tbl.data = &new_value;
else
tbl.data = &net->sctp.rto_max;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
if (new_value > max || new_value < min)
return -EINVAL;
net->sctp.rto_max = new_value;
}
return ret;
}
static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
if (write)
pr_warn_once("Changing rto_alpha or rto_beta may lead to "
"suboptimal rtt/srtt estimations!\n");
return proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
}
static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
struct ctl_table tbl;
int new_value, ret;
memset(&tbl, 0, sizeof(struct ctl_table));
tbl.maxlen = sizeof(unsigned int);
if (write)
tbl.data = &new_value;
else
tbl.data = &net->sctp.auth_enable;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
struct sock *sk = net->sctp.ctl_sock;
net->sctp.auth_enable = new_value;
/* Update the value in the control socket */
lock_sock(sk);
sctp_sk(sk)->ep->auth_enable = new_value;
release_sock(sk);
}
return ret;
}
int sctp_sysctl_net_register(struct net *net)
{
struct ctl_table *table;
int i;
table = kmemdup(sctp_net_table, sizeof(sctp_net_table), GFP_KERNEL);
if (!table)
return -ENOMEM;
for (i = 0; table[i].data; i++)
table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
net->sctp.sysctl_header = register_net_sysctl(net, "net/sctp", table);
if (net->sctp.sysctl_header == NULL) {
kfree(table);
return -ENOMEM;
}
return 0;
}
void sctp_sysctl_net_unregister(struct net *net)
{
struct ctl_table *table;
table = net->sctp.sysctl_header->ctl_table_arg;
unregister_net_sysctl_table(net->sctp.sysctl_header);
kfree(table);
}
static struct ctl_table_header *sctp_sysctl_header;
/* Sysctl registration. */
void sctp_sysctl_register(void)
{
sctp_sysctl_header = register_net_sysctl(&init_net, "net/sctp", sctp_table);
}
/* Sysctl deregistration. */
void sctp_sysctl_unregister(void)
{
unregister_net_sysctl_table(sctp_sysctl_header);
}