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authorDaniel Baumann <daniel.baumann@progress-linux.org>2021-03-04 19:22:03 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2021-03-04 20:43:22 +0000
commit22c74419e2c258319bc723351876604b3304604b (patch)
tree8c799a78d53f67388fdf42900657eda617c1306a /plugins/anonmask/anonmask.c
parentInitial commit. (diff)
downloaddnscap-22c74419e2c258319bc723351876604b3304604b.tar.xz
dnscap-22c74419e2c258319bc723351876604b3304604b.zip
Adding upstream version 2.0.0+debian.upstream/2.0.0+debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'plugins/anonmask/anonmask.c')
-rw-r--r--plugins/anonmask/anonmask.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/plugins/anonmask/anonmask.c b/plugins/anonmask/anonmask.c
new file mode 100644
index 0000000..ca3dc0d
--- /dev/null
+++ b/plugins/anonmask/anonmask.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 2018-2021, OARC, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "dnscap_common.h"
+
+static set_iaddr_t anonmask_set_iaddr = 0;
+
+static logerr_t* logerr;
+static int only_clients = 0, only_servers = 0, mask_port = 53, mask_v4 = 24, mask_v6 = 48;
+static struct in_addr in4 = { INADDR_ANY };
+static struct in6_addr in6 = IN6ADDR_ANY_INIT;
+static uint32_t* in6p = (uint32_t*)&in6;
+
+enum plugin_type anonmask_type()
+{
+ return plugin_filter;
+}
+
+void usage(const char* msg)
+{
+ fprintf(stderr, "anonmask.so usage error: %s\n", msg);
+ exit(1);
+}
+
+void anonmask_usage()
+{
+ fprintf(stderr,
+ "\nanonmask.so options:\n"
+ "\t-? print these instructions and exit\n"
+ "\t-c Only mask clients (port != 53)\n"
+ "\t-s Only mask servers (port == 53)\n"
+ "\t-p <port> Set port for -c/-s masking, default 53\n"
+ "\t-4 <netmask> The /mask for IPv4 addresses, default /24\n"
+ "\t-6 <netmask> The /mask for IPv6 addresses, default /48\n");
+}
+
+void anonmask_extension(int ext, void* arg)
+{
+ switch (ext) {
+ case DNSCAP_EXT_SET_IADDR:
+ anonmask_set_iaddr = (set_iaddr_t)arg;
+ break;
+ }
+}
+
+void anonmask_getopt(int* argc, char** argv[])
+{
+ int c;
+ unsigned long ul;
+ char* p;
+
+ while ((c = getopt(*argc, *argv, "?csp:4:6:")) != EOF) {
+ switch (c) {
+ case 'c':
+ only_clients = 1;
+ break;
+ case 's':
+ only_servers = 1;
+ break;
+ case 'p':
+ ul = strtoul(optarg, &p, 0);
+ if (*p != '\0' || ul < 1U || ul > 65535U)
+ usage("port must be an integer 1..65535");
+ mask_port = (unsigned)ul;
+ break;
+ case '4':
+ ul = strtoul(optarg, &p, 0);
+ if (*p != '\0' || ul > 31U)
+ usage("IPv4 mask must be an integer 0..31");
+ mask_v4 = (unsigned)ul;
+ break;
+ case '6':
+ ul = strtoul(optarg, &p, 0);
+ if (*p != '\0' || ul > 127U)
+ usage("IPv6 mask must be an integer 0..127");
+ mask_v6 = (unsigned)ul;
+ break;
+ case '?':
+ anonmask_usage();
+ if (!optopt || optopt == '?') {
+ exit(0);
+ }
+ // fallthrough
+ default:
+ exit(1);
+ }
+ }
+
+ if (only_clients && only_servers) {
+ usage("-c and -s options are mutually exclusive");
+ }
+
+ if (mask_v4) {
+ in4.s_addr = htonl(0xffffffff << (32 - mask_v4));
+ }
+
+ if (mask_v6) {
+ if (mask_v6 <= 32) {
+ in6p[0] = htonl(0xffffffff << (32 - mask_v6));
+ } else if (mask_v6 <= 64) {
+ in6p[0] = 0xffffffff;
+ in6p[1] = htonl(0xffffffff << (64 - mask_v6));
+ } else if (mask_v6 <= 96) {
+ in6p[0] = 0xffffffff;
+ in6p[1] = 0xffffffff;
+ in6p[2] = htonl(0xffffffff << (96 - mask_v6));
+ } else {
+ in6p[0] = 0xffffffff;
+ in6p[1] = 0xffffffff;
+ in6p[2] = 0xffffffff;
+ in6p[3] = htonl(0xffffffff << (128 - mask_v6));
+ }
+ }
+}
+
+int anonmask_start(logerr_t* a_logerr)
+{
+ logerr = a_logerr;
+ return 0;
+}
+
+void anonmask_stop()
+{
+}
+
+int anonmask_open(my_bpftimeval ts)
+{
+ return 0;
+}
+
+int anonmask_close(my_bpftimeval ts)
+{
+ return 0;
+}
+
+int anonmask_filter(const char* descr, iaddr* from, iaddr* to, uint8_t proto, unsigned flags,
+ unsigned sport, unsigned dport, my_bpftimeval ts,
+ const u_char* pkt_copy, const unsigned olen,
+ const u_char* payload, const unsigned payloadlen)
+{
+ uint32_t* p6;
+
+ for (;;) {
+ if (only_clients && sport == mask_port) {
+ from = 0;
+ break;
+ }
+ if (only_servers && sport != mask_port) {
+ from = 0;
+ break;
+ }
+
+ switch (from->af) {
+ case AF_INET:
+ from->u.a4.s_addr &= in4.s_addr;
+ break;
+ case AF_INET6:
+ p6 = (uint32_t*)&from->u.a6;
+ p6[0] &= in6p[0];
+ p6[1] &= in6p[1];
+ p6[2] &= in6p[2];
+ p6[3] &= in6p[3];
+ break;
+ default:
+ from = 0;
+ break;
+ }
+ break;
+ }
+
+ for (;;) {
+ if (only_clients && dport == mask_port) {
+ to = 0;
+ break;
+ }
+ if (only_servers && dport != mask_port) {
+ to = 0;
+ break;
+ }
+
+ switch (to->af) {
+ case AF_INET:
+ to->u.a4.s_addr &= in4.s_addr;
+ break;
+ case AF_INET6:
+ p6 = (uint32_t*)&to->u.a6;
+ p6[0] &= in6p[0];
+ p6[1] &= in6p[1];
+ p6[2] &= in6p[2];
+ p6[3] &= in6p[3];
+ break;
+ default:
+ to = 0;
+ break;
+ }
+ break;
+ }
+
+ if (anonmask_set_iaddr && (from || to)) {
+ anonmask_set_iaddr(from, to);
+ }
+
+ return 0;
+}