| Message ID | 20170403061127.GA2329@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Pablo Neira |
| Headers | show |
On Mon, Apr 03, 2017 at 03:11:27PM +0900, Ken-ichirou MATSUZAWA wrote: > Recent languages implements array to hold its length. This patch > enables to help to wrap these. As of this C library, we can use > this like below without double sized buffer. > > char buf[MNL_SOCKET_BUFFER_SIZE]; > > b = mnl_nlmsg_batch_start(buf, sizeof(buf)); > nlbuf = mnl_nlmsg_batch_current(b); > rest = mnl_nlmsg_batch_rest(b); > if (rest < NLMSG_HDRLEN) > return false; Only for this usecase above? > nlh = mnl_nlmsg_put_header(nlbuf); Probably we need mnl_nlmsg_put_header_check()? > ... > if (!mnl_attr_put_u8_check(nlh, rest, 1, 2)) > return false; > ... -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Apr 14, 2017 at 12:27:00AM +0200, Pablo Neira Ayuso wrote: > On Mon, Apr 03, 2017 at 03:11:27PM +0900, Ken-ichirou MATSUZAWA wrote: > > enables to help to wrap these. As of this C library, we can use > > this like below without double sized buffer. > > > > char buf[MNL_SOCKET_BUFFER_SIZE]; > > > > b = mnl_nlmsg_batch_start(buf, sizeof(buf)); > > nlbuf = mnl_nlmsg_batch_current(b); > > rest = mnl_nlmsg_batch_rest(b); > > if (rest < NLMSG_HDRLEN) > > return false; > > Only for this usecase above? So far, yes. Is it worthless to apply? > > nlh = mnl_nlmsg_put_header(nlbuf); > > Probably we need mnl_nlmsg_put_header_check()? And I guess mnl_nlmsg_put_extra_header_check will also be needed. I am going to resend if you intend to apply those. Thanks, -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/libmnl/libmnl.h b/include/libmnl/libmnl.h index 0331da7..8cfe137 100644 --- a/include/libmnl/libmnl.h +++ b/include/libmnl/libmnl.h @@ -76,6 +76,7 @@ extern void mnl_nlmsg_batch_reset(struct mnl_nlmsg_batch *b); extern void *mnl_nlmsg_batch_head(struct mnl_nlmsg_batch *b); extern void *mnl_nlmsg_batch_current(struct mnl_nlmsg_batch *b); extern bool mnl_nlmsg_batch_is_empty(struct mnl_nlmsg_batch *b); +extern size_t mnl_nlmsg_batch_rest(const struct mnl_nlmsg_batch *b); /* * Netlink attributes API diff --git a/src/libmnl.map b/src/libmnl.map index e5920e5..97b31d7 100644 --- a/src/libmnl.map +++ b/src/libmnl.map @@ -77,3 +77,7 @@ LIBMNL_1.2 { mnl_socket_open2; mnl_socket_fdopen; } LIBMNL_1.1; + +LIBMNL_1.3 { + mnl_nlmsg_batch_rest; +} LIBMNL_1.2; diff --git a/src/nlmsg.c b/src/nlmsg.c index f9448a5..614e434 100644 --- a/src/nlmsg.c +++ b/src/nlmsg.c @@ -562,5 +562,17 @@ bool mnl_nlmsg_batch_is_empty(struct mnl_nlmsg_batch *b) } /** + * mnl_nlmsg_batch_rest - get the rest of the batch buffer size + * \param b pointer to batch + * + * This function returns the rest of the batch buffer size + */ +EXPORT_SYMBOL(mnl_nlmsg_batch_rest); +size_t mnl_nlmsg_batch_rest(const struct mnl_nlmsg_batch *b) +{ + return b->limit - b->buflen; +} + +/** * @} */
Recent languages implements array to hold its length. This patch enables to help to wrap these. As of this C library, we can use this like below without double sized buffer. char buf[MNL_SOCKET_BUFFER_SIZE]; b = mnl_nlmsg_batch_start(buf, sizeof(buf)); nlbuf = mnl_nlmsg_batch_current(b); rest = mnl_nlmsg_batch_rest(b); if (rest < NLMSG_HDRLEN) return false; nlh = mnl_nlmsg_put_header(nlbuf); ... if (!mnl_attr_put_u8_check(nlh, rest, 1, 2)) return false; ... Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp> --- include/libmnl/libmnl.h | 1 + src/libmnl.map | 4 ++++ src/nlmsg.c | 12 ++++++++++++ 3 files changed, 17 insertions(+)