From 3ff825b28d3345ef381eceae22bf9d92231f23dc Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 9 Nov 2006 16:32:06 -0800 Subject: [PATCH] [TCP]: Add tcp_available_congestion_control sysctl. Create /proc/sys/net/ipv4/tcp_available_congestion_control that reflects currently available TCP choices. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 6 ++++++ include/linux/sysctl.h | 1 + include/net/tcp.h | 4 ++++ net/ipv4/sysctl_net_ipv4.c | 24 ++++++++++++++++++++++++ net/ipv4/tcp_cong.c | 16 ++++++++++++++++ 5 files changed, 51 insertions(+) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index fd3c0c0123..db42808565 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -351,10 +351,16 @@ tcp_frto - BOOLEAN where packet loss is typically due to random radio interference rather than intermediate router congestion. +tcp_available_congestion_control - STRING + Shows the available congestion control choices that are registered. + More congestion control algorithms may be available as modules, + but not loaded. + tcp_congestion_control - STRING Set the congestion control algorithm to be used for new connections. The algorithm "reno" is always available, but additional choices may be available based on kernel configuration. + Default is set as part of kernel configuration. somaxconn - INTEGER Limit of socket listen() backlog, known in userspace as SOMAXCONN. diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index d98562f1df..28a4827965 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -426,6 +426,7 @@ enum NET_CIPSOV4_CACHE_BUCKET_SIZE=119, NET_CIPSOV4_RBM_OPTFMT=120, NET_CIPSOV4_RBM_STRICTVALID=121, + NET_TCP_AVAIL_CONG_CONTROL=122, }; enum { diff --git a/include/net/tcp.h b/include/net/tcp.h index 246916c232..6af4baf5b7 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -620,6 +620,9 @@ enum tcp_ca_event { * Interface for adding new TCP congestion control handlers */ #define TCP_CA_NAME_MAX 16 +#define TCP_CA_MAX 128 +#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) + struct tcp_congestion_ops { struct list_head list; @@ -659,6 +662,7 @@ extern void tcp_init_congestion_control(struct sock *sk); 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 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 15061b3144..2e770f45d8 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -129,6 +129,23 @@ static int sysctl_tcp_congestion_control(ctl_table *table, int __user *name, return ret; } +static int proc_tcp_available_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_available_congestion_control(tbl.data, TCP_CA_BUF_MAX); + ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos); + kfree(tbl.data); + return ret; +} + ctl_table ipv4_table[] = { { .ctl_name = NET_IPV4_TCP_TIMESTAMPS, @@ -731,6 +748,13 @@ ctl_table ipv4_table[] = { .proc_handler = &proc_dointvec, }, #endif /* CONFIG_NETLABEL */ + { + .ctl_name = NET_TCP_AVAIL_CONG_CONTROL, + .procname = "tcp_available_congestion_control", + .maxlen = TCP_CA_BUF_MAX, + .mode = 0444, + .proc_handler = &proc_tcp_available_congestion_control, + }, { .ctl_name = 0 } }; diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index 1e2982f4ac..d846d7b95e 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -139,6 +139,22 @@ static int __init tcp_congestion_default(void) late_initcall(tcp_congestion_default); +/* Build string with list of available congestion control values */ +void tcp_get_available_congestion_control(char *buf, size_t maxlen) +{ + struct tcp_congestion_ops *ca; + size_t offs = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(ca, &tcp_cong_list, list) { + offs += snprintf(buf + offs, maxlen - offs, + "%s%s", + offs == 0 ? "" : " ", ca->name); + + } + rcu_read_unlock(); +} + /* Get current default congestion control */ void tcp_get_default_congestion_control(char *name) { -- 2.20.1