On 21/03/16 23:13, Pablo Neira Ayuso wrote:
On Tue, Mar 15, 2016 at 09:28:07PM +0100, Carlos Falgueras García wrote:Now it is possible to store multiple variable length user data into rule. Modify the parser in order to fill the nftnl_udata with the comment, and the print function for extract these commentary and print it to user. Signed-off-by: Carlos Falgueras García <carlosfg@xxxxxxxxxx> --- include/rule.h | 7 +++++++ src/netlink_delinearize.c | 52 +++++++++++++++++++++++++++++++++++++++++++++-- src/netlink_linearize.c | 16 +++++++++++++-- 3 files changed, 71 insertions(+), 4 deletions(-) diff --git a/include/rule.h b/include/rule.h index c848f0f..b52f0ac 100644 --- a/include/rule.h +++ b/include/rule.h @@ -4,6 +4,7 @@ #include <stdint.h> #include <nftables.h> #include <list.h> +#include <libnftnl/udata.h> /** * struct handle - handle for tables, chains, rules and sets @@ -396,4 +397,10 @@ extern int do_command(struct netlink_ctx *ctx, struct cmd *cmd); extern int cache_update(enum cmd_ops cmd, struct list_head *msgs); extern void cache_release(void); +enum udata_type { + UDATA_TYPE_COMMENT, + __UDATA_TYPE_MAX, +}; +#define UDATA_TYPE_MAX (__UDATA_TYPE_MAX - 1) + #endif /* NFTABLES_RULE_H */ diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c index d431588..5fcb5c1 100644 --- a/src/netlink_delinearize.c +++ b/src/netlink_delinearize.c @@ -25,6 +25,7 @@ #include <utils.h> #include <erec.h> #include <sys/socket.h> +#include <libnftnl/udata.h> struct netlink_parse_ctx { struct list_head *msgs; @@ -1746,6 +1747,54 @@ static void rule_parse_postprocess(struct netlink_parse_ctx *ctx, struct rule *r } } +static int parse_udata_cb(const struct nftnl_udata *attr, void *data) +{ + unsigned char *value = nftnl_udata_attr_value(attr); + uint8_t type = nftnl_udata_attr_type(attr); + uint8_t len = nftnl_udata_attr_len(attr); + const struct nftnl_udata **tb = data; + + switch (type) { + case UDATA_TYPE_COMMENT: + if (value[len - 1] != '\0') + return -1; + break; + default: + break; + }; + + tb[type] = attr; + return 1; +} + +static char *udata_get_comment(const void *data, uint32_t data_len) +{ + const struct nftnl_udata *tb[UDATA_TYPE_MAX + 1] = {}; + struct nftnl_udata_buf *udata; + uint8_t attr_len; + char *comment = NULL; + + udata = nftnl_udata_alloc(data_len); + if (!udata) + memory_allocation_error(); + nftnl_udata_copy_data(udata, data, data_len); + + if (nftnl_udata_parse(udata, parse_udata_cb, tb) <= 0) + goto exit;I think this should be instead: if (nftnl_udata_parse(data, data_len, parse_udata_cb, tb) <= 0) So you don't need to allocate the buffer then copy data into it. I think the buffer infrastructure is only necessary to build the TLV attributes, not to parse it.
Ok.
+ if (!tb[UDATA_TYPE_COMMENT]) + goto exit; + + attr_len = nftnl_udata_attr_len(tb[UDATA_TYPE_COMMENT]); + comment = xmalloc(attr_len); + memcpy(comment, nftnl_udata_attr_value(tb[UDATA_TYPE_COMMENT]), + attr_len);I'd suggest: comment = xstrdup(nftnl_udata_attr_get_str(tb[UDATA_TYPE_COMMENT]));
I'll change this.
+ +exit: + nftnl_udata_free(udata); + return comment; +} + struct rule *netlink_delinearize_rule(struct netlink_ctx *ctx, const struct nftnl_rule *nlr) {
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