From patchwork Thu Nov 15 15:50:10 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 199327 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D09802C0412 for ; Fri, 16 Nov 2012 02:48:25 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756740Ab2KOPsV (ORCPT ); Thu, 15 Nov 2012 10:48:21 -0500 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:41027 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993447Ab2KOPsV (ORCPT ); Thu, 15 Nov 2012 10:48:21 -0500 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.72) (envelope-from ) id 1TZ1fv-0008Tr-P4; Thu, 15 Nov 2012 16:48:19 +0100 From: Florian Westphal To: netfilter-devel Cc: Florian Westphal Subject: [PATCH 2/3] api: add connlabel api and attribute Date: Thu, 15 Nov 2012 16:50:10 +0100 Message-Id: <1352994611-3707-3-git-send-email-fw@strlen.de> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1352994611-3707-1-git-send-email-fw@strlen.de> References: <1352994611-3707-1-git-send-email-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org 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 #include 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 + +#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 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 +#include #include 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, };