expr: add osf support

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index 141b04a329e7973b12766a31278f8f04cc965980..fd0befc16f6e99579525069c188b7a741a4205d1 100644 (file)
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -274,6 +274,10 @@ enum {
        NFTNL_EXPR_OBJREF_SET_ID,
 };
 
+enum {
+       NFTNL_EXPR_OSF_DREG     = NFTNL_EXPR_BASE,
+};
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index 4b3a95e8cc9e66e22ca04650c9bf24e1a4574719..cc21ef082cd2388699d46c4878cd93a04e485149 100644 (file)
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -931,6 +931,18 @@ enum nft_socket_keys {
 };
 #define NFT_SOCKET_MAX (__NFT_SOCKET_MAX - 1)
 
+/**
+ * enum nft_osf_attributes - nf_tables osf expression netlink attributes
+ *
+ * @NFTA_OSF_DREG: OS to match
+ */
+enum nft_osf_attributes {
+       NFTA_OSF_UNSPEC,
+       NFTA_OSF_DREG,
+       __NFTA_OSF_MAX,
+};
+#define NFTA_OSF_MAX (__NFTA_OSF_MAX - 1)
+
 /**
  * enum nft_ct_keys - nf_tables ct expression keys
  *

diff --git a/src/Makefile.am b/src/Makefile.am
index fc03661145d0249e62bfc35cb53f7d68a05c2f4e..f92b4d2d214db51302760e54f375f0802f78afc0 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -57,6 +57,7 @@ libnftnl_la_SOURCES = utils.c         \
                      expr/redir.c      \
                      expr/hash.c       \
                      expr/socket.c     \
+                     expr/osf.c        \
                      obj/counter.c     \
                      obj/ct_helper.c   \
                      obj/quota.c       \

diff --git a/src/expr/osf.c b/src/expr/osf.c
new file mode 100644 (file)
index 0000000..a005af8
--- /dev/null
+++ b/src/expr/osf.c
@@ -0,0 +1,174 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+
+#define OSF_GENRE_SIZE 32
+
+struct nftnl_expr_osf {
+       enum nft_registers      dreg;
+};
+
+static int nftnl_expr_osf_set(struct nftnl_expr *e, uint16_t type,
+                             const void *data, uint32_t data_len)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+
+       switch(type) {
+       case NFTNL_EXPR_OSF_DREG:
+               osf->dreg = *((uint32_t *)data);
+               break;
+       }
+       return 0;
+}
+
+static const void *
+nftnl_expr_osf_get(const struct nftnl_expr *e, uint16_t type,
+                  uint32_t *data_len)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+
+       switch(type) {
+       case NFTNL_EXPR_OSF_DREG:
+               *data_len = sizeof(osf->dreg);
+               return &osf->dreg;
+       }
+       return NULL;
+}
+
+static int nftnl_expr_osf_cb(const struct nlattr *attr, void *data)
+{
+       const struct nlattr **tb = data;
+       int type = mnl_attr_get_type(attr);
+
+       if (mnl_attr_type_valid(attr, NFTA_OSF_MAX) < 0)
+               return MNL_CB_OK;
+
+       switch(type) {
+       case NFTNL_EXPR_OSF_DREG:
+               if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+                       abi_breakage();
+               break;
+       }
+
+       tb[type] = attr;
+       return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_osf_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+
+       if (e->flags & (1 << NFTNL_EXPR_OSF_DREG))
+               mnl_attr_put_u32(nlh, NFTNL_EXPR_OSF_DREG, htonl(osf->dreg));
+}
+
+static int
+nftnl_expr_osf_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+       struct nlattr *tb[NFTA_OSF_MAX + 1] = {};
+
+       if (mnl_attr_parse_nested(attr, nftnl_expr_osf_cb, tb) < 0)
+               return -1;
+
+       if (tb[NFTA_OSF_DREG]) {
+               osf->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_OSF_DREG]));
+               e->flags |= (1 << NFTNL_EXPR_OSF_DREG);
+       }
+
+       return 0;
+}
+
+static int nftnl_expr_osf_json_parse(struct nftnl_expr *e, json_t *root,
+                                    struct nftnl_parse_err *err)
+{
+#ifdef JSON_PARSING
+       __u32 dreg;
+
+       genre = nftnl_jansson_parse_u32(root, "dreg", err);
+       if (genre != NULL)
+               nftnl_expr_set_u32(e, NFTNL_EXPR_OSF_DREG, );
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static int nftnl_expr_osf_snprintf_default(char *buf, size_t size,
+                                          const struct nftnl_expr *e)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+       int ret, offset = 0, len = size;
+
+       if (e->flags & (1 << NFTNL_EXPR_OSF_DREG)) {
+               ret = snprintf(buf, len, "%u", osf->dreg);
+               SNPRINTF_BUFFER_SIZE(ret, len, offset);
+       }
+
+       return offset;
+}
+
+static int nftnl_expr_osf_export(char *buf, size_t size,
+                                const struct nftnl_expr *e, int type)
+{
+       struct nftnl_expr_osf *osf = nftnl_expr_data(e);
+       NFTNL_BUF_INIT(b, buf, size);
+
+       if (e->flags & (1 << NFTNL_EXPR_OSF_DREG))
+               nftnl_buf_u32(&b, type, osf->dreg, "dreg");
+
+       return nftnl_buf_done(&b);
+}
+
+static int
+nftnl_expr_osf_snprintf(char *buf, size_t len, uint32_t type,
+                       uint32_t flags, const struct nftnl_expr *e)
+{
+       switch(type) {
+       case NFTNL_OUTPUT_DEFAULT:
+               return nftnl_expr_osf_snprintf_default(buf, len, e);
+       case NFTNL_OUTPUT_XML:
+       case NFTNL_OUTPUT_JSON:
+               return nftnl_expr_osf_export(buf, len, e, type);
+       default:
+               break;
+       }
+       return -1;
+}
+
+static bool nftnl_expr_osf_cmp(const struct nftnl_expr *e1,
+                              const struct nftnl_expr *e2)
+{
+       struct nftnl_expr_osf *l1 = nftnl_expr_data(e1);
+       struct nftnl_expr_osf *l2 = nftnl_expr_data(e2);
+       bool eq = true;
+
+       if (e1->flags & (1 << NFTNL_EXPR_OSF_DREG))
+               eq &= (l1->dreg == l2->dreg);
+
+       return eq;
+}
+
+struct expr_ops expr_ops_osf = {
+       .name           = "osf",
+       .alloc_len      = sizeof(struct nftnl_expr_osf),
+       .max_attr       = NFTA_OSF_MAX,
+       .cmp            = nftnl_expr_osf_cmp,
+       .set            = nftnl_expr_osf_set,
+       .get            = nftnl_expr_osf_get,
+       .parse          = nftnl_expr_osf_parse,
+       .build          = nftnl_expr_osf_build,
+       .snprintf       = nftnl_expr_osf_snprintf,
+       .json_parse     = nftnl_expr_osf_json_parse,
+};

diff --git a/src/expr_ops.c b/src/expr_ops.c
index 72a4679b6e8931163596b9d9aab8f58b06e10c42..23a9bcc7aad742d769737944dfc3a934ac0ec2ed 100644 (file)
--- a/src/expr_ops.c
+++ b/src/expr_ops.c
@@ -37,6 +37,7 @@ extern struct expr_ops expr_ops_hash;
 extern struct expr_ops expr_ops_fib;
 extern struct expr_ops expr_ops_flow;
 extern struct expr_ops expr_ops_socket;
+extern struct expr_ops expr_ops_osf;
 
 static struct expr_ops expr_ops_notrack = {
        .name   = "notrack",
@@ -77,6 +78,7 @@ static struct expr_ops *expr_ops[] = {
        &expr_ops_objref,
        &expr_ops_flow,
        &expr_ops_socket,
+       &expr_ops_osf,
        NULL,
 };