adds new labelmap api to create a name <-> bit mapping
from a text file (default: /etc/xtables/connlabel.conf).
nfct_labelmap_new(filename) is used to create the map,
nfct_labelmap_destroy() releases the resources allocated for the map.
Two functions are added to make map lookups:
nfct_labelmap_get_name(map, bit) returns the name of a bit,
nfct_labelmap_get_bit returns the bit associated with a name.
The connlabel attribute is represented by a nfct_bitmask object, the
nfct_bitmask api can be used to test/set/get individual bits
("labels").
The exisiting nfct_attr_get/set interfaces can be used to read or
replace the existing labels associated with a conntrack with a new set.
---
include/internal/object.h | 4 +
include/internal/prototypes.h | 9 +
.../libnetfilter_conntrack.h | 9 +
.../linux_nfnetlink_conntrack.h | 1 +
src/conntrack/Makefile.am | 1 +
src/conntrack/api.c | 65 ++++++
src/conntrack/build_mnl.c | 12 +
src/conntrack/getter.c | 6 +
src/conntrack/labels.c | 239 ++++++++++++++++++++
src/conntrack/parse.c | 1 +
src/conntrack/parse_mnl.c | 25 ++
src/conntrack/setter.c | 12 +
12 files changed, 384 insertions(+), 0 deletions(-)
create mode 100644 src/conntrack/labels.c
diff --git a/include/internal/object.h b/include/internal/object.h
index 609265d..bbb038a 100644
--- a/include/internal/object.h
+++ b/include/internal/object.h
@@ -189,6 +189,8 @@ struct nf_conntrack {
void *helper_info;
size_t helper_info_len;
+
+ struct nfct_bitmask *connlabels;
};
/*
@@ -305,4 +307,6 @@ struct nfct_bitmask {
uint32_t bits[];
};
+struct nfct_labelmap;
+
#endif
diff --git a/include/internal/prototypes.h b/include/internal/prototypes.h
index eeeea24..484deea 100644
--- a/include/internal/prototypes.h
+++ b/include/internal/prototypes.h
@@ -54,4 +54,13 @@ int __snprintf_expect(char *buf, unsigned int len, const struct nf_expect *exp,
int __snprintf_expect_default(char *buf, unsigned int len, const struct nf_expect *exp, unsigned int msg_type, unsigned int flags);
int __snprintf_expect_xml(char *buf, unsigned int len, const struct nf_expect *exp, unsigned int msg_type, unsigned int flags);
+/*
+ * connlabel internal prototypes
+ */
+struct nfct_labelmap *__labelmap_new(const char *);
+void __labelmap_destroy(struct nfct_labelmap *);
+
+int __labelmap_get_bit(struct nfct_labelmap *map, const char *name);
+const char *__labelmap_get_name(struct nfct_labelmap *map, unsigned int bit);
+
#endif
diff --git a/include/libnetfilter_conntrack/libnetfilter_conntrack.h b/include/libnetfilter_conntrack/libnetfilter_conntrack.h
index 97e2dd7..e3b1f47 100644
--- a/include/libnetfilter_conntrack/libnetfilter_conntrack.h
+++ b/include/libnetfilter_conntrack/libnetfilter_conntrack.h
@@ -133,6 +133,7 @@ enum nf_conntrack_attr {
ATTR_TIMESTAMP_START, /* u64 bits, linux >= 2.6.38 */
ATTR_TIMESTAMP_STOP = 64, /* u64 bits, linux >= 2.6.38 */
ATTR_HELPER_INFO, /* variable length */
+ ATTR_CONNLABELS, /* variable length */
ATTR_MAX
};
@@ -284,6 +285,14 @@ int nfct_bitmask_test_bit(const struct nfct_bitmask *, unsigned int bit);
void nfct_bitmask_unset_bit(struct nfct_bitmask *, unsigned int bit);
void nfct_bitmask_destroy(struct nfct_bitmask *);
+/* connlabel name <-> bit translation mapping */
+struct nfct_labelmap;
+
+struct nfct_labelmap *nfct_labelmap_new(const char *mapfile);
+void nfct_labelmap_destroy(struct nfct_labelmap *map);
+const char *nfct_labelmap_get_name(struct nfct_labelmap *m, unsigned int bit);
+int nfct_labelmap_get_bit(struct nfct_labelmap *m, const char *name);
+
/* setter */
extern void nfct_set_attr(struct nf_conntrack *ct,
const enum nf_conntrack_attr type,
diff --git a/include/libnetfilter_conntrack/linux_nfnetlink_conntrack.h b/include/libnetfilter_conntrack/linux_nfnetlink_conntrack.h
index 1e32c7f..fab40ae 100644
--- a/include/libnetfilter_conntrack/linux_nfnetlink_conntrack.h
+++ b/include/libnetfilter_conntrack/linux_nfnetlink_conntrack.h
@@ -51,6 +51,7 @@ enum ctattr_type {
CTA_SECCTX,
CTA_TIMESTAMP,
CTA_MARK_MASK,
+ CTA_LABELS,
__CTA_MAX
};
#define CTA_MAX (__CTA_MAX - 1)
diff --git a/src/conntrack/Makefile.am b/src/conntrack/Makefile.am
index 01fed53..e1d8768 100644
--- a/src/conntrack/Makefile.am
+++ b/src/conntrack/Makefile.am
@@ -4,6 +4,7 @@ noinst_LTLIBRARIES = libnfconntrack.la
libnfconntrack_la_SOURCES = api.c \
getter.c setter.c \
+ labels.c \
parse.c build.c \
parse_mnl.c build_mnl.c \
snprintf.c \
diff --git a/src/conntrack/api.c b/src/conntrack/api.c
index f1fcdc4..6dd7675 100644
--- a/src/conntrack/api.c
+++ b/src/conntrack/api.c
@@ -95,6 +95,8 @@ void nfct_destroy(struct nf_conntrack *ct)
free(ct->secctx);
if (ct->helper_info)
free(ct->helper_info);
+ if (ct->connlabels)
+ nfct_bitmask_destroy(ct->connlabels);
free(ct);
ct = NULL; /* bugtrap */
}
@@ -1485,6 +1487,69 @@ void nfct_filter_dump_set_attr_u8(struct nfct_filter_dump *filter_dump,
*/
/**
+ * \defgroup label Conntrack labels
+ *
+ * @{
+ */
+
+/**
+ * nfct_labelmap_get_name - get name of the label bit
+ *
+ * \param m label map obtained from nfct_label_open
+ * \param bit whose name should be returned
+ *
+ * returns a pointer to the name associated with the label.
+ * If no name has been configured, the empty string is returned.
+ * If bit is out of range, NULL is returned.
+ */
+const char *nfct_labelmap_get_name(struct nfct_labelmap *m, unsigned int bit)
+{
+ return __labelmap_get_name(m, bit);
+}
+
+/**
+ * nfct_labelmap_get_bit - get bit associated with the name
+ *
+ * \param h label handle obtained from nfct_labelmap_new
+ * \param name name of the label
+ *
+ * returns the bit associated with the name, or negative value on error.
+ */
+int nfct_labelmap_get_bit(struct nfct_labelmap *m, const char *name)
+{
+ return __labelmap_get_bit(m, name);
+}
+
+/**
+ * nfct_labelmap_new - create a new label map
+ *
+ * \param mapfile the file containing the bit <-> name mapping
+ *
+ * If mapfile is NULL, the default mapping file is used.
+ * returns a new label map, or NULL on error.
+ */
+struct nfct_labelmap *nfct_labelmap_new(const char *mapfile)
+{
+ return __labelmap_new(mapfile);
+}
+
+/**
+ * nfct_labelmap_destroy - destroy nfct_labelmap object
+ *
+ * \param map the label object to destroy.
+ *
+ * This function releases the memory that is used by the labelmap object.
+ */
+void nfct_labelmap_destroy(struct nfct_labelmap *map)
+{
+ __labelmap_destroy(map);
+}
+
+/**
+ * @}
+ */
+
+/*
* \defgroup bitmask bitmask object
*
* @{
diff --git a/src/conntrack/build_mnl.c b/src/conntrack/build_mnl.c
index 46aec8a..a666e01 100644
--- a/src/conntrack/build_mnl.c
+++ b/src/conntrack/build_mnl.c
@@ -10,6 +10,7 @@
*/
#include "internal/internal.h"
+#include <limits.h>
#include <libmnl/libmnl.h>
static int
@@ -379,6 +380,14 @@ nfct_build_zone(struct nlmsghdr *nlh, const struct nf_conntrack *ct)
return 0;
}
+static void
+nfct_build_labels(struct nlmsghdr *nlh, const struct nf_conntrack *ct)
+{
+ struct nfct_bitmask *b = ct->connlabels;
+ unsigned int size = b->words * sizeof(b->bits[0]);
+ mnl_attr_put(nlh, CTA_LABELS, size, b->bits);
+}
+
int
nfct_nlmsg_build(struct nlmsghdr *nlh, const struct nf_conntrack *ct)
{
@@ -475,5 +484,8 @@ nfct_nlmsg_build(struct nlmsghdr *nlh, const struct nf_conntrack *ct)
if (test_bit(ATTR_ZONE, ct->head.set))
nfct_build_zone(nlh, ct);
+ if (test_bit(ATTR_CONNLABELS, ct->head.set))
+ nfct_build_labels(nlh, ct);
+
return 0;
}
diff --git a/src/conntrack/getter.c b/src/conntrack/getter.c
index e7ab048..53c9e0e 100644
--- a/src/conntrack/getter.c
+++ b/src/conntrack/getter.c
@@ -339,6 +339,11 @@ static const void *get_attr_helper_info(const struct nf_conntrack *ct)
return ct->helper_info;
}
+static const void *get_attr_connlabels(const struct nf_conntrack *ct)
+{
+ return ct->connlabels;
+}
+
const get_attr get_attr_array[ATTR_MAX] = {
[ATTR_ORIG_IPV4_SRC] = get_attr_orig_ipv4_src,
[ATTR_ORIG_IPV4_DST] = get_attr_orig_ipv4_dst,
@@ -406,4 +411,5 @@ const get_attr get_attr_array[ATTR_MAX] = {
[ATTR_TIMESTAMP_START] = get_attr_timestamp_start,
[ATTR_TIMESTAMP_STOP] = get_attr_timestamp_stop,
[ATTR_HELPER_INFO] = get_attr_helper_info,
+ [ATTR_CONNLABELS] = get_attr_connlabels,
};
diff --git a/src/conntrack/labels.c b/src/conntrack/labels.c
new file mode 100644
index 0000000..b64995f
--- /dev/null
+++ b/src/conntrack/labels.c
@@ -0,0 +1,239 @@
+#include <stdint.h>
+
+#include "internal/internal.h"
+
+#define MAX_BITS 1024
+
+#define CONNLABEL_CFG "/etc/xtables/connlabel.conf"
+#define HASH_SIZE 64
+
+struct labelmap_bucket {
+ char *name;
+ unsigned int bit;
+ struct labelmap_bucket *next;
+};
+
+struct nfct_labelmap {
+ struct labelmap_bucket *map_name[HASH_SIZE];
+ unsigned int namecount;
+ char **bit_to_name;
+};
+
+static struct labelmap_bucket* label_map_bucket_alloc(const char *n, unsigned int b)
+{
+ struct labelmap_bucket *bucket;
+ char *name = strdup(n);
+
+ if (!name)
+ return NULL;
+
+ bucket = malloc(sizeof(*bucket));
+ if (!bucket) {
+ free(name);
+ return NULL;
+ }
+ bucket->name = name;
+ bucket->bit = b;
+ return bucket;
+}
+
+static unsigned int hash_name(const char *name)
+{
+ unsigned int hash = 0;
+
+ while (*name) {
+ hash = (hash << 5) - hash + *name;
+ name++;
+ }
+ return hash & (HASH_SIZE - 1);
+}
+
+int __labelmap_get_bit(struct nfct_labelmap *m, const char *name)
+{
+ unsigned int i = hash_name(name);
+ struct labelmap_bucket *list = m->map_name[i];
+
+ while (list) {
+ if (strcmp(name, list->name) == 0)
+ return list->bit;
+ list = list->next;
+ }
+ return -1;
+}
+
+const char *__labelmap_get_name(struct nfct_labelmap *m, unsigned int bit)
+{
+ if (bit < m->namecount)
+ return m->bit_to_name[bit] ? m->bit_to_name[bit] : "";
+ return NULL;
+}
+
+static int map_insert(struct nfct_labelmap *m, const char *n, unsigned int b)
+{
+ unsigned int i = hash_name(n);
+ struct labelmap_bucket *list = m->map_name[i];
+
+ while (list) {
+ if (list->bit == b)
+ return -1;
+ list = list->next;
+ }
+
+ list = label_map_bucket_alloc(n, b);
+ if (!list)
+ return -1;
+
+ if (m->map_name[i])
+ list->next = m->map_name[i];
+ else
+ list->next = NULL;
+ m->map_name[i] = list;
+ return 0;
+}
+
+static int is_space_posix(int c)
+{
+ return c == ' ' || c == '\f' || c == '\r' || c == '\t' || c == '\v';
+}
+
+static char *trim_label(char *label)
+{
+ char *end;
+
+ while (is_space_posix(*label))
+ label++;
+ end = strchr(label, '\n');
+ if (end)
+ *end = 0;
+ else
+ end = strchr(label, '\0');
+ end--;
+
+ while (is_space_posix(*end) && end > label) {
+ *end = 0;
+ end--;
+ }
+
+ return *label ? label : NULL;
+}
+
+static int
+xtables_parse_connlabel_numerical(const char *s, char **end)
+{
+ unsigned long value;
+
+ value = strtoul(s, end, 0);
+ if (value == 0 && s == *end)
+ return -1;
+ if (value < 0 || value >= MAX_BITS)
+ return -1;
+ return value;
+}
+
+static void free_list(struct labelmap_bucket *b)
+{
+ if (b->next)
+ free_list(b->next);
+ free(b->name);
+ free(b);
+}
+
+void __labelmap_destroy(struct nfct_labelmap *map)
+{
+ unsigned int i;
+ struct labelmap_bucket *b;
+
+ for (i = 0; i < HASH_SIZE; i++) {
+ b = map->map_name[i];
+ if (b != NULL)
+ free_list(b);
+ }
+
+ free(map->bit_to_name);
+ free(map);
+}
+
+static void make_name_table(struct nfct_labelmap *m)
+{
+ struct labelmap_bucket *b;
+ unsigned int i;
+
+ for (i = 0; i < HASH_SIZE; i++) {
+ b = m->map_name[i];
+ while (b) {
+ m->bit_to_name[b->bit] = b->name;
+ b = b->next;
+ }
+ }
+}
+
+static struct nfct_labelmap *map_alloc(void)
+{
+ struct nfct_labelmap *map = malloc(sizeof(*map));
+ if (map) {
+ unsigned int i;
+ for (i = 0; i < HASH_SIZE; i++)
+ map->map_name[i] = NULL;
+ }
+ return map;
+}
+
+struct nfct_labelmap *__labelmap_new(const char *name)
+{
+ struct nfct_labelmap *map;
+ char label[1024];
+ char *end;
+ FILE *fp;
+ int added = 0;
+ unsigned int maxbit = 0;
+ uint32_t bits_seen[MAX_BITS/32];
+
+ fp = fopen(name ? name : CONNLABEL_CFG, "re");
+ if (!fp)
+ return NULL;
+
+ memset(bits_seen, 0, sizeof(bits_seen));
+
+ map = map_alloc();
+ if (!map) {
+ fclose(fp);
+ return NULL;
+ }
+
+ while (fgets(label, sizeof(label), fp)) {
+ int bit;
+
+ if (label[0] == '#')
+ continue;
+
+ bit = xtables_parse_connlabel_numerical(label, &end);
+ if (bit < 0 || test_bit(bit, bits_seen))
+ continue;
+
+ end = trim_label(end);
+ if (!end)
+ continue;
+ if (map_insert(map, end, bit) == 0) {
+ added++;
+ if (maxbit < bit)
+ maxbit = bit;
+ set_bit(bit, bits_seen);
+ }
+ }
+
+ fclose(fp);
+
+ if (added) {
+ map->namecount = maxbit + 1;
+ map->bit_to_name = calloc(sizeof(char *), map->namecount);
+ if (!map->bit_to_name)
+ goto err;
+ make_name_table(map);
+ return map;
+ }
+ err:
+ __labelmap_destroy(map);
+ return NULL;
+}
+
+
diff --git a/src/conntrack/parse.c b/src/conntrack/parse.c
index b9f9a99..6096e8d 100644
--- a/src/conntrack/parse.c
+++ b/src/conntrack/parse.c
@@ -8,6 +8,7 @@
*/
#include "internal/internal.h"
+#include <libmnl/libmnl.h>
static void __parse_ip(const struct nfattr *attr,
struct __nfct_tuple *tuple,
diff --git a/src/conntrack/parse_mnl.c b/src/conntrack/parse_mnl.c
index 93f6681..a4272f9 100644
--- a/src/conntrack/parse_mnl.c
+++ b/src/conntrack/parse_mnl.c
@@ -11,6 +11,7 @@
#include "internal/internal.h"
#include <libmnl/libmnl.h>
+#include <limits.h>
#include <endian.h>
static int
@@ -772,6 +773,25 @@ nfct_parse_timestamp(const struct nlattr *attr, struct nf_conntrack *ct)
return 0;
}
+static int nfct_parse_labels(const struct nlattr *attr, struct nf_conntrack *ct)
+{
+ uint16_t len = mnl_attr_get_payload_len(attr);
+ struct nfct_bitmask *mask;
+ uint32_t *bits;
+
+ if (len == 0)
+ return 0;
+
+ mask = nfct_bitmask_new((len * CHAR_BIT) - 1);
+ if (!mask)
+ return -1;
+ bits = mnl_attr_get_payload(attr);
+ if (len)
+ memcpy(mask->bits, bits, len);
+ nfct_set_attr(ct, ATTR_CONNLABELS, mask);
+ return 0;
+}
+
static int
nfct_parse_conntrack_attr_cb(const struct nlattr *attr, void *data)
{
@@ -934,6 +954,11 @@ nfct_payload_parse(const void *payload, size_t payload_len,
return -1;
}
+ if (tb[CTA_LABELS]) {
+ if (nfct_parse_labels(tb[CTA_LABELS], ct) < 0)
+ return -1;
+ }
+
return 0;
}
diff --git a/src/conntrack/setter.c b/src/conntrack/setter.c
index dbcd68e..8879f02 100644
--- a/src/conntrack/setter.c
+++ b/src/conntrack/setter.c
@@ -421,6 +421,17 @@ retry:
}
static void
+set_attr_connlabels(struct nf_conntrack *ct, const void *value, size_t len)
+{
+ if (ct->connlabels == value)
+ return;
+
+ if (ct->connlabels)
+ nfct_bitmask_destroy(ct->connlabels);
+ ct->connlabels = (void *) value;
+}
+
+static void
set_attr_do_nothing(struct nf_conntrack *ct, const void *value, size_t len) {}
const set_attr set_attr_array[ATTR_MAX] = {
@@ -490,4 +501,5 @@ const set_attr set_attr_array[ATTR_MAX] = {
[ATTR_TIMESTAMP_START] = set_attr_do_nothing,
[ATTR_TIMESTAMP_STOP] = set_attr_do_nothing,
[ATTR_HELPER_INFO] = set_attr_helper_info,
+ [ATTR_CONNLABELS] = set_attr_connlabels,
};
--
1.7.8.6
--
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