From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Carlos=20Falgueras=20Garc=C3=ADa?= Subject: [PATCH 1/4 v5] libnftnl: Implement new buffer of TLV objects Date: Tue, 15 Mar 2016 21:28:04 +0100 Message-ID: <1458073687-23870-1-git-send-email-carlosfg@riseup.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: pablo@netfilter.org, kaber@trash.net To: netfilter-devel@vger.kernel.org Return-path: Received: from mx1.riseup.net ([198.252.153.129]:53873 "EHLO mx1.riseup.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934932AbcCOU3a (ORCPT ); Tue, 15 Mar 2016 16:29:30 -0400 Sender: netfilter-devel-owner@vger.kernel.org List-ID: These functions allow to create a buffer (nftnl_udata_buf) of TLV objec= ts (nftnl_udata). It is inspired by libmnl/src/attr.c. It can be used to s= tore several variable length user data into an object. Example usage: ``` struct nftnl_udata_buf *buf; struct nftnl_udata *attr; const char str[] =3D "Hello World!"; buf =3D nftnl_udata_alloc(UDATA_SIZE); if (!buf) { perror("OOM"); exit(EXIT_FAILURE); } if (!nftnl_udata_put_strz(buf, MY_TYPE, str)) { perror("Can't put attribute \"%s\"", str); exit(EXIT_FAILURE); } nftnl_udata_for_each(buf, attr) { printf("%s\n", (char *)nftnl_udata_attr_value(attr)); } nftnl_udata_free(buf); ``` Signed-off-by: Carlos Falgueras Garc=C3=ADa --- include/Makefile.am | 1 + include/libnftnl/Makefile.am | 1 + include/libnftnl/udata.h | 49 ++++++++++++++++ include/udata.h | 40 +++++++++++++ src/Makefile.am | 1 + src/libnftnl.map | 32 +++++++++++ src/udata.c | 133 +++++++++++++++++++++++++++++++++++= ++++++++ 7 files changed, 257 insertions(+) create mode 100644 include/libnftnl/udata.h create mode 100644 include/udata.h create mode 100644 src/udata.c diff --git a/include/Makefile.am b/include/Makefile.am index be9eb9b..9f55737 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -12,4 +12,5 @@ noinst_HEADERS =3D internal.h \ expr.h \ json.h \ set_elem.h \ + udata.h \ utils.h diff --git a/include/libnftnl/Makefile.am b/include/libnftnl/Makefile.a= m index 84f01b6..457ec95 100644 --- a/include/libnftnl/Makefile.am +++ b/include/libnftnl/Makefile.am @@ -7,4 +7,5 @@ pkginclude_HEADERS =3D batch.h \ set.h \ ruleset.h \ common.h \ + udata.h \ gen.h diff --git a/include/libnftnl/udata.h b/include/libnftnl/udata.h new file mode 100644 index 0000000..f65a1dc --- /dev/null +++ b/include/libnftnl/udata.h @@ -0,0 +1,49 @@ +#ifndef _LIBNFTNL_UDATA_H_ +#define _LIBNFTNL_UDATA_H_ + +#include +#include +#include + +/* + * nftnl user data attributes API + */ +struct nftnl_udata; +struct nftnl_udata_buf; + +/* nftnl_udata_buf */ +struct nftnl_udata_buf *nftnl_udata_alloc(uint32_t data_size); +void nftnl_udata_free(struct nftnl_udata_buf *buf); +uint32_t nftnl_udata_len(const struct nftnl_udata_buf *buf); +uint32_t nftnl_udata_size(const struct nftnl_udata_buf *buf); +void *nftnl_udata_data(const struct nftnl_udata_buf *buf); +void nftnl_udata_copy_data(struct nftnl_udata_buf *buf, const void *da= ta, + uint32_t len); +struct nftnl_udata *nftnl_udata_start(const struct nftnl_udata_buf *bu= f); +struct nftnl_udata *nftnl_udata_end(const struct nftnl_udata_buf *buf)= ; + +/* putters */ +bool nftnl_udata_put(struct nftnl_udata_buf *buf, uint8_t type, uint32= _t len, + const void *value); +bool nftnl_udata_put_strz(struct nftnl_udata_buf *buf, uint8_t type, + const char *strz); + +/* nftnl_udata_attr */ +uint8_t nftnl_udata_attr_type(const struct nftnl_udata *attr); +uint8_t nftnl_udata_attr_len(const struct nftnl_udata *attr); +void *nftnl_udata_attr_value(const struct nftnl_udata *attr); + +/* iterator */ +struct nftnl_udata *nftnl_udata_attr_next(const struct nftnl_udata *at= tr); + +#define nftnl_udata_for_each(buf, attr) \ + for ((attr) =3D nftnl_udata_start(buf); \ + (char *)(nftnl_udata_end(buf)) > (char *)(attr); \ + (attr) =3D nftnl_udata_attr_next(attr)) + +typedef int (*nftnl_udata_cb_t)(const struct nftnl_udata *attr, + void *data); +int nftnl_udata_parse(const struct nftnl_udata_buf *buf, nftnl_udata_c= b_t cb, + void *data); + +#endif /* _LIBNFTNL_UDATA_H_ */ diff --git a/include/udata.h b/include/udata.h new file mode 100644 index 0000000..407a3b9 --- /dev/null +++ b/include/udata.h @@ -0,0 +1,40 @@ +#ifndef _LIBNFTNL_UDATA_INTERNAL_H_ +#define _LIBNFTNL_UDATA_INTERNAL_H_ + +#include +#include + +/* + * TLV structures: + * nftnl_udata + * <-------- HEADER --------> <------ PAYLOAD ------> + * +------------+-------------+- - - - - - - - - - - -+ + * | type | len | value | + * | (1 byte) | (1 byte) | | + * +--------------------------+- - - - - - - - - - - -+ + * <-- sizeof(nftnl_udata) -> <-- nftnl_udata->len --> + */ +struct nftnl_udata { + uint8_t type; + uint8_t len; + unsigned char value[]; +} __attribute__((__packed__)); + +/* + * +---------------------------------++ + * | data[] || + * | || || + * | \/ \/ + * +-------+-------+-------+-------+ ... +-------+- - - - - - -+ + * | size | end | TLV | TLV | | TLV | Empty | + * +-------+-------+-------+-------+ ... +-------+- - - - - - -+ + * |<---- nftnl_udata_len() ---->| + * |<----------- nftnl_udata_size() ---------->| + */ +struct nftnl_udata_buf { + uint32_t size; + char *end; + char data[]; +}; + +#endif /* _LIBNFTNL_UDATA_INTERNAL_H_ */ diff --git a/src/Makefile.am b/src/Makefile.am index a27e292..7e580e4 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -19,6 +19,7 @@ libnftnl_la_SOURCES =3D utils.c \ ruleset.c \ mxml.c \ jansson.c \ + udata.c \ expr.c \ expr_ops.c \ expr/bitwise.c \ diff --git a/src/libnftnl.map b/src/libnftnl.map index 2e193b7..329caca 100644 --- a/src/libnftnl.map +++ b/src/libnftnl.map @@ -336,6 +336,22 @@ global: nftnl_set_snprintf; nftnl_set_fprintf; =20 + nftnl_udata_alloc; + nftnl_udata_free; + nftnl_udata_len; + nftnl_udata_size; + nftnl_udata_data; + nftnl_udata_copy_data; + nftnl_udata_start; + nftnl_udata_end; + nftnl_udata_put; + nftnl_udata_put_strz; + nftnl_udata_attr_type; + nftnl_udata_attr_len; + nftnl_udata_attr_value; + nftnl_udata_attr_next; + nftnl_udata_parse; + nftnl_set_list_alloc; nftnl_set_list_free; nftnl_set_list_add; @@ -512,4 +528,20 @@ LIBNFTNL_4.1 { nftnl_trace_get_data; =20 nftnl_trace_nlmsg_parse; + + nftnl_udata_alloc; + nftnl_udata_free; + nftnl_udata_len; + nftnl_udata_size; + nftnl_udata_data; + nftnl_udata_copy_data; + nftnl_udata_start; + nftnl_udata_end; + nftnl_udata_put; + nftnl_udata_put_strz; + nftnl_udata_attr_type; + nftnl_udata_attr_len; + nftnl_udata_attr_value; + nftnl_udata_attr_next; + nftnl_udata_parse; } LIBNFTNL_4; diff --git a/src/udata.c b/src/udata.c new file mode 100644 index 0000000..61ee6c9 --- /dev/null +++ b/src/udata.c @@ -0,0 +1,133 @@ +#include +#include +#include + +#include +#include +#include + +struct nftnl_udata_buf *nftnl_udata_alloc(uint32_t data_size) +{ + struct nftnl_udata_buf *buf; + + buf =3D malloc(sizeof(struct nftnl_udata_buf) + data_size); + if (!buf) + return NULL; + buf->size =3D data_size; + buf->end =3D buf->data; + + return buf; +} +EXPORT_SYMBOL(nftnl_udata_alloc); + +void nftnl_udata_free(struct nftnl_udata_buf *buf) +{ + buf->size =3D 0; + buf->end =3D NULL; + free(buf); +} +EXPORT_SYMBOL(nftnl_udata_free); + +uint32_t nftnl_udata_len(const struct nftnl_udata_buf *buf) +{ + return (uint32_t)(buf->end - buf->data); +} +EXPORT_SYMBOL(nftnl_udata_len); + +uint32_t nftnl_udata_size(const struct nftnl_udata_buf *buf) +{ + return buf->size; +} +EXPORT_SYMBOL(nftnl_udata_size); + +void *nftnl_udata_data(const struct nftnl_udata_buf *buf) +{ + return (void *)buf->data; +} +EXPORT_SYMBOL(nftnl_udata_data); + +void nftnl_udata_copy_data(struct nftnl_udata_buf *buf, const void *da= ta, + uint32_t len) +{ + memcpy(buf->data, data, len <=3D buf->size ? len : buf->size); + buf->end =3D buf->data + len; +} +EXPORT_SYMBOL(nftnl_udata_copy_data); + +struct nftnl_udata *nftnl_udata_start(const struct nftnl_udata_buf *bu= f) +{ + return (struct nftnl_udata *)buf->data; +} +EXPORT_SYMBOL(nftnl_udata_start); + +struct nftnl_udata *nftnl_udata_end(const struct nftnl_udata_buf *buf) +{ + return (struct nftnl_udata *)buf->end; +} +EXPORT_SYMBOL(nftnl_udata_end); + +bool nftnl_udata_put(struct nftnl_udata_buf *buf, uint8_t type, uint32= _t len, + const void *value) +{ + struct nftnl_udata *attr; + + if (buf->size < len + sizeof(struct nftnl_udata)) + return false; + + attr =3D (struct nftnl_udata *)buf->end; + attr->len =3D len; + attr->type =3D type; + memcpy(attr->value, value, len); + + buf->end =3D (char *)nftnl_udata_attr_next(attr); + + return true; +} +EXPORT_SYMBOL(nftnl_udata_put); + +bool nftnl_udata_put_strz(struct nftnl_udata_buf *buf, uint8_t type, + const char *strz) +{ + return nftnl_udata_put(buf, type, strlen(strz) + 1, strz); +} +EXPORT_SYMBOL(nftnl_udata_put_strz); + +uint8_t nftnl_udata_attr_type(const struct nftnl_udata *attr) +{ + return attr->type; +} +EXPORT_SYMBOL(nftnl_udata_attr_type); + +uint8_t nftnl_udata_attr_len(const struct nftnl_udata *attr) +{ + return attr->len; +} +EXPORT_SYMBOL(nftnl_udata_attr_len); + +void *nftnl_udata_attr_value(const struct nftnl_udata *attr) +{ + return (void *)attr->value; +} +EXPORT_SYMBOL(nftnl_udata_attr_value); + +struct nftnl_udata *nftnl_udata_attr_next(const struct nftnl_udata *at= tr) +{ + return (struct nftnl_udata *)&attr->value[attr->len]; +} +EXPORT_SYMBOL(nftnl_udata_attr_next); + +int nftnl_udata_parse(const struct nftnl_udata_buf *buf, nftnl_udata_c= b_t cb, + void *data) +{ + int ret =3D 0; + const struct nftnl_udata *attr; + + nftnl_udata_for_each(buf, attr) { + ret =3D cb(attr, data); + if (ret <=3D 0) + return ret; + } + + return ret; +} +EXPORT_SYMBOL(nftnl_udata_parse); --=20 2.7.2 -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html