diff options
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 6 | ||||
| -rw-r--r-- | include/linux/sysctl.h | 1 | ||||
| -rw-r--r-- | include/net/tcp.h | 3 | ||||
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 52 | ||||
| -rw-r--r-- | net/ipv4/tcp_cong.c | 63 |
5 files changed, 125 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index db42808..bbcc8de 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -351,6 +351,12 @@ tcp_frto - BOOLEAN where packet loss is typically due to random radio interference rather than intermediate router congestion. +tcp_allowed_congestion_control - STRING + Show/set the congestion control choices available to non-privileged + processes. The list is a subset of those listed in + tcp_available_congestion_control. + Default is "reno" and the default setting (tcp_congestion_control). + tcp_available_congestion_control - STRING Shows the available congestion control choices that are registered. More congestion control algorithms may be available as modules, diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 28a4827..0725441 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -427,6 +427,7 @@ enum NET_CIPSOV4_RBM_OPTFMT=120, NET_CIPSOV4_RBM_STRICTVALID=121, NET_TCP_AVAIL_CONG_CONTROL=122, + NET_TCP_ALLOWED_CONG_CONTROL=123, }; enum { diff --git a/include/net/tcp.h b/include/net/tcp.h index 6af4baf..e1a5d29 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -625,6 +625,7 @@ enum tcp_ca_event { struct tcp_congestion_ops { struct list_head list; + int non_restricted; /* initialize private data (optional) */ void (*init)(struct sock *sk); @@ -663,6 +664,8 @@ extern void tcp_cleanup_congestion_control(struct sock *sk); extern int tcp_set_default_congestion_control(const char *name); extern void tcp_get_default_congestion_control(char *name); extern void tcp_get_available_congestion_control(char *buf, size_t len); +extern void tcp_get_allowed_congestion_control(char *buf, size_t len); +extern int tcp_set_allowed_congestion_control(char *allowed); extern int tcp_set_congestion_control(struct sock *sk, const char *name); extern void tcp_slow_start(struct tcp_sock *tp); diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 2e770f4..dfcf47f 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -146,6 +146,50 @@ static int proc_tcp_available_congestion_control(ctl_table *ctl, return ret; } +static int proc_allowed_congestion_control(ctl_table *ctl, + int write, struct file * filp, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX }; + int ret; + + tbl.data = kmalloc(tbl.maxlen, GFP_USER); + if (!tbl.data) + return -ENOMEM; + + tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen); + ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos); + if (write && ret == 0) + ret = tcp_set_allowed_congestion_control(tbl.data); + kfree(tbl.data); + return ret; +} + +static int strategy_allowed_congestion_control(ctl_table *table, int __user *name, + int nlen, void __user *oldval, + size_t __user *oldlenp, + void __user *newval, size_t newlen, + void **context) +{ + ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX }; + int ret; + + tbl.data = kmalloc(tbl.maxlen, GFP_USER); + if (!tbl.data) + return -ENOMEM; + + tcp_get_available_congestion_control(tbl.data, tbl.maxlen); + ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen, + context); + if (ret == 0 && newval && newlen) + ret = tcp_set_allowed_congestion_control(tbl.data); + kfree(tbl.data); + + return ret; + +} + ctl_table ipv4_table[] = { { .ctl_name = NET_IPV4_TCP_TIMESTAMPS, @@ -755,6 +799,14 @@ ctl_table ipv4_table[] = { .mode = 0444, .proc_handler = &proc_tcp_available_congestion_control, }, + { + .ctl_name = NET_TCP_ALLOWED_CONG_CONTROL, + .procname = "tcp_allowed_congestion_control", + .maxlen = TCP_CA_BUF_MAX, + .mode = 0644, + .proc_handler = &proc_allowed_congestion_control, + .strategy = &strategy_allowed_congestion_control, + }, { .ctl_name = 0 } }; diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index d846d7b..343d619 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -123,6 +123,7 @@ int tcp_set_default_congestion_control(const char *name) #endif if (ca) { + ca->non_restricted = 1; /* default is always allowed */ list_move(&ca->list, &tcp_cong_list); ret = 0; } @@ -168,6 +169,64 @@ void tcp_get_default_congestion_control(char *name) rcu_read_unlock(); } +/* Built list of non-restricted congestion control values */ +void tcp_get_allowed_congestion_control(char *buf, size_t maxlen) +{ + struct tcp_congestion_ops *ca; + size_t offs = 0; + + *buf = '\0'; + rcu_read_lock(); + list_for_each_entry_rcu(ca, &tcp_cong_list, list) { + if (!ca->non_restricted) + continue; + offs += snprintf(buf + offs, maxlen - offs, + "%s%s", + offs == 0 ? "" : " ", ca->name); + + } + rcu_read_unlock(); +} + +/* Change list of non-restricted congestion control */ +int tcp_set_allowed_congestion_control(char *val) +{ + struct tcp_congestion_ops *ca; + char *clone, *name; + int ret = 0; + + clone = kstrdup(val, GFP_USER); + if (!clone) + return -ENOMEM; + + spin_lock(&tcp_cong_list_lock); + /* pass 1 check for bad entries */ + while ((name = strsep(&clone, " ")) && *name) { + ca = tcp_ca_find(name); + if (!ca) { + ret = -ENOENT; + goto out; + } + } + + /* pass 2 clear */ + list_for_each_entry_rcu(ca, &tcp_cong_list, list) + ca->non_restricted = 0; + + /* pass 3 mark as allowed */ + while ((name = strsep(&val, " ")) && *name) { + ca = tcp_ca_find(name); + WARN_ON(!ca); + if (ca) + ca->non_restricted = 1; + } +out: + spin_unlock(&tcp_cong_list_lock); + + return ret; +} + + /* Change congestion control for socket */ int tcp_set_congestion_control(struct sock *sk, const char *name) { @@ -183,6 +242,9 @@ int tcp_set_congestion_control(struct sock *sk, const char *name) if (!ca) err = -ENOENT; + else if (!(ca->non_restricted || capable(CAP_NET_ADMIN))) + err = -EPERM; + else if (!try_module_get(ca->owner)) err = -EBUSY; @@ -284,6 +346,7 @@ EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd); struct tcp_congestion_ops tcp_reno = { .name = "reno", + .non_restricted = 1, .owner = THIS_MODULE, .ssthresh = tcp_reno_ssthresh, .cong_avoid = tcp_reno_cong_avoid, |
