From d99f160ac53e51090f015a8f0617cea25f81a191 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 5 Nov 2006 23:52:12 -0800 Subject: [PATCH] sysctl: allow a zero ctl_name in the middle of a sysctl table Since it is becoming clear that there are just enough users of the binary sysctl interface that completely removing the binary interface from the kernel will not be an option for foreseeable future, we need to find a way to address the sysctl maintenance issues. The basic problem is that sysctl requires one central authority to allocate sysctl numbers, or else conflicts and ABI breakage occur. The proc interface to sysctl does not have that problem, as names are not densely allocated. By not terminating a sysctl table until I have neither a ctl_name nor a procname, it becomes simple to add sysctl entries that don't show up in the binary sysctl interface. Which allows people to avoid allocating a binary sysctl value when not needed. I have audited the kernel code and in my reading I have not found a single sysctl table that wasn't terminated by a completely zero filled entry. So this change in behavior should not affect anything. I think this mechanism eases the pain enough that combined with a little disciple we can solve the reoccurring sysctl ABI breakage. Signed-off-by: Eric W. Biederman Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sysctl.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 1b24bd45e080..c184732a70fc 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -961,8 +961,8 @@ extern ctl_handler sysctl_ms_jiffies; /* * Register a set of sysctl names by calling register_sysctl_table * with an initialised array of ctl_table's. An entry with zero - * ctl_name terminates the table. table->de will be set up by the - * registration and need not be initialised in advance. + * ctl_name and NULL procname terminates the table. table->de will be + * set up by the registration and need not be initialised in advance. * * sysctl names can be mirrored automatically under /proc/sys. The * procname supplied controls /proc naming. @@ -973,7 +973,10 @@ extern ctl_handler sysctl_ms_jiffies; * Leaf nodes in the sysctl tree will be represented by a single file * under /proc; non-leaf nodes will be represented by directories. A * null procname disables /proc mirroring at this node. - * + * + * sysctl entries with a zero ctl_name will not be available through + * the binary sysctl interface. + * * sysctl(2) can automatically manage read and write requests through * the sysctl table. The data and maxlen fields of the ctl_table * struct enable minimal validation of the values being written to be -- cgit v1.2.3 From 7cc13edc139108bb527b692f0548dce6bc648572 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 5 Nov 2006 23:52:13 -0800 Subject: [PATCH] sysctl: implement CTL_UNNUMBERED This patch takes the CTL_UNNUMBERD concept from NFS and makes it available to all new sysctl users. At the same time the sysctl binary interface maintenance documentation is updated to mention and to describe what is needed to successfully maintain the sysctl binary interface. Signed-off-by: Eric W. Biederman Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sysctl.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index c184732a70fc..d98562f1df76 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -6,10 +6,17 @@ **************************************************************** **************************************************************** ** + ** WARNING: ** The values in this file are exported to user space via - ** the sysctl() binary interface. However this interface - ** is unstable and deprecated and will be removed in the future. - ** For a stable interface use /proc/sys. + ** the sysctl() binary interface. Do *NOT* change the + ** numbering of any existing values here, and do not change + ** any numbers within any one set of values. If you have to + ** have to redefine an existing interface, use a new number for it. + ** The kernel will then return -ENOTDIR to any application using + ** the old binary interface. + ** + ** For new interfaces unless you really need a binary number + ** please use CTL_UNNUMBERED. ** **************************************************************** **************************************************************** @@ -48,6 +55,7 @@ struct __sysctl_args { #ifdef __KERNEL__ #define CTL_ANY -1 /* Matches any name */ #define CTL_NONE 0 +#define CTL_UNNUMBERED CTL_NONE /* sysctl without a binary number */ #endif enum -- cgit v1.2.3 From 3ff825b28d3345ef381eceae22bf9d92231f23dc Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 9 Nov 2006 16:32:06 -0800 Subject: [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 --- include/linux/sysctl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index d98562f1df76..28a48279654d 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 { -- cgit v1.2.3 From ce7bc3bf15cbf5dc5a5587ccb6b04c5b4dde4336 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 9 Nov 2006 16:35:15 -0800 Subject: [TCP]: Restrict congestion control choices. Allow normal users to only choose among a restricted set of congestion control choices. The default is reno and what ever has been configured as default. But the policy can be changed by administrator at any time. For example, to allow any choice: cp /proc/sys/net/ipv4/tcp_available_congestion_control \ /proc/sys/net/ipv4/tcp_allowed_congestion_control Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- include/linux/sysctl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 28a48279654d..0725441621d0 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 { -- cgit v1.2.3 From 2e2e9e92bd723244ea20fa488b1780111f2b05e1 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Mon, 13 Nov 2006 13:23:52 -0200 Subject: [DCCP]: Add sysctls to control retransmission behaviour This adds 3 sysctls which govern the retransmission behaviour of DCCP control packets (3way handshake, feature negotiation). It removes 4 FIXMEs from the code. The close resemblance of sysctl variables to their TCP analogues is emphasised not only by their name, but also by giving them the same initial values. This is useful since there is not much practical experience with DCCP yet. Furthermore, with regard to the previous patch, it is now possible to limit the number of keepalive-Responses by setting net.dccp.default.request_retries (also a bit like in TCP). Lastly, added documentation of all existing DCCP sysctls. Signed-off-by: Gerrit Renker Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/sysctl.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 0725441621d0..2e8c5ad82793 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -614,6 +614,9 @@ enum { NET_DCCP_DEFAULT_ACK_RATIO = 4, NET_DCCP_DEFAULT_SEND_ACKVEC = 5, NET_DCCP_DEFAULT_SEND_NDP = 6, + NET_DCCP_DEFAULT_REQ_RETRIES = 7, + NET_DCCP_DEFAULT_RETRIES1 = 8, + NET_DCCP_DEFAULT_RETRIES2 = 9, }; /* /proc/sys/net/ipx */ -- cgit v1.2.3 From 82e3ab9dbeebd5c8d5402ad1607d22086271a56d Mon Sep 17 00:00:00 2001 From: Ian McDonald Date: Mon, 20 Nov 2006 19:19:32 -0200 Subject: [DCCP]: Adds the tx buffer sysctls This one got lost on the way from Ian to Gerrit to me, fix it. Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/sysctl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 2e8c5ad82793..61dd99c6c2a5 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -617,6 +617,7 @@ enum { NET_DCCP_DEFAULT_REQ_RETRIES = 7, NET_DCCP_DEFAULT_RETRIES1 = 8, NET_DCCP_DEFAULT_RETRIES2 = 9, + NET_DCCP_DEFAULT_TX_QLEN = 10, }; /* /proc/sys/net/ipx */ -- cgit v1.2.3 From 4384260443efe90a2ec0d907568dbc58ae792cd0 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 28 Nov 2006 18:14:10 -0200 Subject: [DCCP]: Remove allocation of sysctl numbers This is in response to a request sent earlier by Eric W. Biederman and replaces all sysctl numbers for net.dccp.default with CTL_UNNUMBERED. It has been tested to compile and to work. Commiter note: I've removed the use of CTL_UNNUMBERED, not setting .ctl_name sets it to 0, that is the what CTL_UNNUMBERED is, reason is to avoid unneeded source code cluttering. Signed-off-by: Gerrit Renker Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/sysctl.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'include/linux/sysctl.h') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 61dd99c6c2a5..94316a98e0d0 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -606,20 +606,6 @@ enum { NET_DCCP_DEFAULT=1, }; -/* /proc/sys/net/dccp/default */ -enum { - NET_DCCP_DEFAULT_SEQ_WINDOW = 1, - NET_DCCP_DEFAULT_RX_CCID = 2, - NET_DCCP_DEFAULT_TX_CCID = 3, - NET_DCCP_DEFAULT_ACK_RATIO = 4, - NET_DCCP_DEFAULT_SEND_ACKVEC = 5, - NET_DCCP_DEFAULT_SEND_NDP = 6, - NET_DCCP_DEFAULT_REQ_RETRIES = 7, - NET_DCCP_DEFAULT_RETRIES1 = 8, - NET_DCCP_DEFAULT_RETRIES2 = 9, - NET_DCCP_DEFAULT_TX_QLEN = 10, -}; - /* /proc/sys/net/ipx */ enum { NET_IPX_PPROP_BROADCASTING=1, -- cgit v1.2.3