Direct specifications like "upto" are easier to grasp than "not
above". This patch adds such an upto variant similar to what
libxt_hashlimit already has.
Signed-off-by: Jan Engelhardt <jengelh@xxxxxxxxxx>
---
extensions/libxt_connlimit.c | 70 ++++++++++++++++++++++++---------------
extensions/libxt_connlimit.man | 9 +++--
2 files changed, 49 insertions(+), 30 deletions(-)
diff --git a/extensions/libxt_connlimit.c b/extensions/libxt_connlimit.c
index 693adbf..b249259 100644
--- a/extensions/libxt_connlimit.c
+++ b/extensions/libxt_connlimit.c
@@ -9,16 +9,22 @@
#include <xtables.h>
#include <linux/netfilter/xt_connlimit.h>
+enum {
+ FL_LIMIT = 1 << 0,
+ FL_MASK = 1 << 1,
+};
+
static void connlimit_help(void)
{
printf(
"connlimit match options:\n"
-"[!] --connlimit-above n match if the number of existing "
-" connections is (not) above n\n"
-" --connlimit-mask n group hosts using prefix length (default: max len)\n");
+" --connlimit-upto n match if the number of existing connections is 0..n\n"
+" --connlimit-above n match if the number of existing connections is >n\n"
+" --connlimit-mask n group hosts using prefix length (default: max len)\n");
}
static const struct option connlimit_opts[] = {
+ {.name = "connlimit-upto", .has_arg = true, .val = 'U'},
{.name = "connlimit-above", .has_arg = true, .val = 'A'},
{.name = "connlimit-mask", .has_arg = true, .val = 'M'},
XT_GETOPT_TABLEEND,
@@ -61,21 +67,28 @@ static int connlimit_parse(int c, char **argv, int invert, unsigned int *flags,
int i;
switch (c) {
- case 'A':
- if (*flags & 0x1)
- xtables_error(PARAMETER_PROBLEM,
- "--connlimit-above may be given only once");
- *flags |= 0x1;
- xtables_check_inverse(optarg, &invert, &optind, 0, argv);
- info->limit = strtoul(optarg, NULL, 0);
- info->inverse = invert;
- break;
- case 'M':
- if (*flags & 0x2)
- xtables_error(PARAMETER_PROBLEM,
- "--connlimit-mask may be given only once");
-
- *flags |= 0x2;
+ case 'A': /* --connlimit-above */
+ xtables_param_act(XTF_ONLY_ONCE, "connlimit",
+ "--connlimit-{upto,above}", *flags & FL_LIMIT);
+ *flags |= FL_LIMIT;
+ if (invert)
+ info->inverse = true;
+ info->limit = strtoul(optarg, NULL, 0);
+ return true;
+ case 'U': /* --connlimit-upto */
+ xtables_param_act(XTF_ONLY_ONCE, "connlimit",
+ "--connlimit-{upto,above}", *flags & FL_LIMIT);
+ *flags |= FL_LIMIT;
+ if (!invert)
+ info->inverse = true;
+ info->limit = strtoul(optarg, NULL, 0);
+ return true;
+ case 'M': /* --connlimit-mask */
+ xtables_param_act(XTF_NO_INVERT, "connlimit",
+ "--connlimit-mask", invert);
+ xtables_param_act(XTF_ONLY_ONCE, "connlimit",
+ "--connlimit-mask", *flags & FL_MASK);
+ *flags |= FL_MASK;
i = strtoul(optarg, &err, 0);
if (family == NFPROTO_IPV6) {
if (i > 128 || *err != '\0')
@@ -93,10 +106,9 @@ static int connlimit_parse(int c, char **argv, int invert, unsigned int *flags,
else
info->v4_mask = htonl(0xFFFFFFFF << (32 - i));
}
- break;
+ return true;
}
-
- return 1;
+ return false;
}
static int connlimit_parse4(int c, char **argv, int invert,
@@ -164,18 +176,22 @@ static void connlimit_save4(const void *ip, const struct xt_entry_match *match)
{
const struct xt_connlimit_info *info = (const void *)match->data;
- printf("%s--connlimit-above %u --connlimit-mask %u ",
- info->inverse ? "! " : "", info->limit,
- count_bits4(info->v4_mask));
+ if (info->inverse)
+ printf("--connlimit-upto %u ", info->limit);
+ else
+ printf("--connlimit-above %u ", info->limit);
+ printf("--connlimit-mask %u ", count_bits4(info->v4_mask));
}
static void connlimit_save6(const void *ip, const struct xt_entry_match *match)
{
const struct xt_connlimit_info *info = (const void *)match->data;
- printf("%s--connlimit-above %u --connlimit-mask %u ",
- info->inverse ? "! " : "", info->limit,
- count_bits6(info->v6_mask));
+ if (info->inverse)
+ printf("--connlimit-upto %u ", info->limit);
+ else
+ printf("--connlimit-above %u ", info->limit);
+ printf("--connlimit-mask %u ", count_bits6(info->v6_mask));
}
static struct xtables_match connlimit_mt_reg[] = {
diff --git a/extensions/libxt_connlimit.man b/extensions/libxt_connlimit.man
index f8f9c7b..ecc8027 100644
--- a/extensions/libxt_connlimit.man
+++ b/extensions/libxt_connlimit.man
@@ -1,8 +1,11 @@
Allows you to restrict the number of parallel connections to a server per
client IP address (or client address block).
.TP
-[\fB!\fP] \fB\-\-connlimit\-above\fP \fIn\fP
-Match if the number of existing connections is (not) above \fIn\fP.
+\fB\-\-connlimit\-upto\fP \fIn\fP
+Match if the number of existing connections is below or equal \fIn\fP.
+.TP
+\fB\-\-connlimit\-above\fP \fIn\fP
+Match if the number of existing connections is above \fIn\fP.
.TP
\fB\-\-connlimit\-mask\fP \fIprefix_length\fP
Group hosts using the prefix length. For IPv4, this must be a number between
@@ -15,7 +18,7 @@ Examples:
iptables \-A INPUT \-p tcp \-\-syn \-\-dport 23 \-m connlimit \-\-connlimit\-above 2 \-j REJECT
.TP
# you can also match the other way around:
-iptables \-A INPUT \-p tcp \-\-syn \-\-dport 23 \-m connlimit ! \-\-connlimit\-above 2 \-j ACCEPT
+iptables \-A INPUT \-p tcp \-\-syn \-\-dport 23 \-m connlimit \-\-connlimit\-upto 2 \-j ACCEPT
.TP
# limit the number of parallel HTTP requests to 16 per class C sized \
network (24 bit netmask)
--
1.7.1
--
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