From 1bab4c75075b84675b96992ac47580a57c26958d Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Thu, 24 Jul 2014 16:50:37 +0200 Subject: [PATCH] inet: frag: set limits and make init_net's high_thresh limit global This patch makes init_net's high_thresh limit to be the maximum for all namespaces, thus introducing a global memory limit threshold equal to the sum of the individual high_thresh limits which are capped. It also introduces some sane minimums for low_thresh as it shouldn't be able to drop below 0 (or > high_thresh in the unsigned case), and overall low_thresh should not ever be above high_thresh, so we make the following relations for a namespace: init_net: high_thresh - max(not capped), min(init_net low_thresh) low_thresh - max(init_net high_thresh), min (0) all other namespaces: high_thresh = max(init_net high_thresh), min(namespace's low_thresh) low_thresh = max(namespace's high_thresh), min(0) The major issue with having low_thresh > high_thresh is that we'll schedule eviction but never evict anything and thus rely only on the timers. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 3 ++- net/ieee802154/reassembly.c | 12 ++++++++++-- net/ipv4/ip_fragment.c | 10 ++++++++-- net/ipv6/netfilter/nf_conntrack_reasm.c | 12 ++++++++++-- net/ipv6/reassembly.c | 12 ++++++++++-- 5 files changed, 40 insertions(+), 9 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index e8c304e37831..29a93518bf18 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -101,7 +101,8 @@ ipfrag_high_thresh - INTEGER Maximum memory used to reassemble IP fragments. When ipfrag_high_thresh bytes of memory is allocated for this purpose, the fragment handler will toss packets until ipfrag_low_thresh - is reached. + is reached. This also serves as a maximum limit to namespaces + different from the initial one. ipfrag_low_thresh - INTEGER Maximum memory used to reassemble IP fragments before the kernel diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c index 8da635d92a58..f13d4f32e207 100644 --- a/net/ieee802154/reassembly.c +++ b/net/ieee802154/reassembly.c @@ -386,20 +386,25 @@ err: EXPORT_SYMBOL(lowpan_frag_rcv); #ifdef CONFIG_SYSCTL +static int zero; + static struct ctl_table lowpan_frags_ns_ctl_table[] = { { .procname = "6lowpanfrag_high_thresh", .data = &init_net.ieee802154_lowpan.frags.high_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &init_net.ieee802154_lowpan.frags.low_thresh }, { .procname = "6lowpanfrag_low_thresh", .data = &init_net.ieee802154_lowpan.frags.low_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &init_net.ieee802154_lowpan.frags.high_thresh }, { .procname = "6lowpanfrag_time", @@ -446,7 +451,10 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) goto err_alloc; table[0].data = &ieee802154_lowpan->frags.high_thresh; + table[0].extra1 = &ieee802154_lowpan->frags.low_thresh; + table[0].extra2 = &init_net.ieee802154_lowpan.frags.high_thresh; table[1].data = &ieee802154_lowpan->frags.low_thresh; + table[1].extra2 = &ieee802154_lowpan->frags.high_thresh; table[2].data = &ieee802154_lowpan->frags.timeout; table[3].data = &ieee802154_lowpan->max_dsize; diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index ccee68dffd6e..634fc31aa243 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -700,14 +700,17 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = { .data = &init_net.ipv4.frags.high_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &init_net.ipv4.frags.low_thresh }, { .procname = "ipfrag_low_thresh", .data = &init_net.ipv4.frags.low_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &init_net.ipv4.frags.high_thresh }, { .procname = "ipfrag_time", @@ -752,7 +755,10 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net) goto err_alloc; table[0].data = &net->ipv4.frags.high_thresh; + table[0].extra1 = &net->ipv4.frags.low_thresh; + table[0].extra2 = &init_net.ipv4.frags.high_thresh; table[1].data = &net->ipv4.frags.low_thresh; + table[1].extra2 = &net->ipv4.frags.high_thresh; table[2].data = &net->ipv4.frags.timeout; /* Don't export sysctls to unprivileged users */ diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 4d9da1e35f8c..3d4bccf6d67d 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -63,6 +63,8 @@ struct nf_ct_frag6_skb_cb static struct inet_frags nf_frags; #ifdef CONFIG_SYSCTL +static int zero; + static struct ctl_table nf_ct_frag6_sysctl_table[] = { { .procname = "nf_conntrack_frag6_timeout", @@ -76,14 +78,17 @@ static struct ctl_table nf_ct_frag6_sysctl_table[] = { .data = &init_net.nf_frag.frags.low_thresh, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &init_net.nf_frag.frags.high_thresh }, { .procname = "nf_conntrack_frag6_high_thresh", .data = &init_net.nf_frag.frags.high_thresh, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = &init_net.nf_frag.frags.low_thresh }, { } }; @@ -102,7 +107,10 @@ static int nf_ct_frag6_sysctl_register(struct net *net) table[0].data = &net->nf_frag.frags.timeout; table[1].data = &net->nf_frag.frags.low_thresh; + table[1].extra2 = &net->nf_frag.frags.high_thresh; table[2].data = &net->nf_frag.frags.high_thresh; + table[2].extra1 = &net->nf_frag.frags.low_thresh; + table[2].extra2 = &init_net.nf_frag.frags.high_thresh; } hdr = register_net_sysctl(net, "net/netfilter", table); diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 57a9707b2032..f1709c4a289a 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -578,20 +578,25 @@ static const struct inet6_protocol frag_protocol = }; #ifdef CONFIG_SYSCTL +static int zero; + static struct ctl_table ip6_frags_ns_ctl_table[] = { { .procname = "ip6frag_high_thresh", .data = &init_net.ipv6.frags.high_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &init_net.ipv6.frags.low_thresh }, { .procname = "ip6frag_low_thresh", .data = &init_net.ipv6.frags.low_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &init_net.ipv6.frags.high_thresh }, { .procname = "ip6frag_time", @@ -628,7 +633,10 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net) goto err_alloc; table[0].data = &net->ipv6.frags.high_thresh; + table[0].extra1 = &net->ipv6.frags.low_thresh; + table[0].extra2 = &init_net.ipv6.frags.high_thresh; table[1].data = &net->ipv6.frags.low_thresh; + table[1].extra2 = &net->ipv6.frags.high_thresh; table[2].data = &net->ipv6.frags.timeout; /* Don't export sysctls to unprivileged users */