[PATCH 1/2] iproute2: add libgenl files
From: Julian Anastasov <ja@ssi.bg>
Date: 2012-09-08 09:45:43
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Create libgenl.h and libgenl.c. They will contain common code for GENL users such as ipl2tp, tcp_metrics, etc. Signed-off-by: Julian Anastasov <ja@ssi.bg> --- include/libgenl.h | 25 ++++++++++++++++++++ lib/Makefile | 2 +- lib/libgenl.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 91 insertions(+), 1 deletions(-) create mode 100644 include/libgenl.h create mode 100644 lib/libgenl.c
diff --git a/include/libgenl.h b/include/libgenl.h
new file mode 100644
index 0000000..ef455c1
--- /dev/null
+++ b/include/libgenl.h@@ -0,0 +1,25 @@ +#ifndef __LIBGENL_H__ +#define __LIBGENL_H__ + +#include "libnetlink.h" + +#define GENL_DEFINE_REQUEST(req, hdrsize, bufsiz) \ +struct { \ + struct nlmsghdr n; \ + struct genlmsghdr g; \ + char buf[NLMSG_ALIGN(hdrsize) + bufsiz]; \ +} req + +#define GENL_INIT_REQUEST(req, family, hdrsize, ver, cmd_, flags) \ + do { \ + memset(&req, 0, sizeof(req)); \ + req.n.nlmsg_type = family; \ + req.n.nlmsg_flags = flags; \ + req.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN + hdrsize); \ + req.g.cmd = cmd_; \ + req.g.version = ver; \ + } while (0) + +int libgenl_resolve_family(struct rtnl_handle *grth, const char *family); + +#endif /* __LIBGENL_H__ */
diff --git a/lib/Makefile b/lib/Makefile
index da2f0fc..bfbe672 100644
--- a/lib/Makefile
+++ b/lib/Makefile@@ -2,7 +2,7 @@ CFLAGS += -fPIC UTILOBJ=utils.o rt_names.o ll_types.o ll_proto.o ll_addr.o inet_proto.o -NLOBJ=ll_map.o libnetlink.o +NLOBJ=libgenl.o ll_map.o libnetlink.o all: libnetlink.a libutil.a
diff --git a/lib/libgenl.c b/lib/libgenl.c
new file mode 100644
index 0000000..c1bf399
--- /dev/null
+++ b/lib/libgenl.c@@ -0,0 +1,65 @@ +/* + * libgenl.c GENL library + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include <linux/genetlink.h> +#include "libgenl.h" + +static int libgenl_parse_getfamily(struct nlmsghdr *nlh) +{ + struct rtattr *tb[CTRL_ATTR_MAX + 1]; + struct genlmsghdr *ghdr = NLMSG_DATA(nlh); + int len = nlh->nlmsg_len; + struct rtattr *attrs; + + if (nlh->nlmsg_type != GENL_ID_CTRL) { + fprintf(stderr, "Not a controller message, nlmsg_len=%d " + "nlmsg_type=0x%x\n", nlh->nlmsg_len, nlh->nlmsg_type); + return -1; + } + + len -= NLMSG_LENGTH(GENL_HDRLEN); + + if (len < 0) { + fprintf(stderr, "wrong controller message len %d\n", len); + return -1; + } + + if (ghdr->cmd != CTRL_CMD_NEWFAMILY) { + fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd); + return -1; + } + + attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN); + parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len); + + if (tb[CTRL_ATTR_FAMILY_ID] == NULL) { + fprintf(stderr, "Missing family id TLV\n"); + return -1; + } + + return rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]); +} + +int libgenl_resolve_family(struct rtnl_handle *grth, const char *family) +{ + GENL_DEFINE_REQUEST(req, 0, 1024); + + GENL_INIT_REQUEST(req, GENL_ID_CTRL, 0, 0, CTRL_CMD_GETFAMILY, + NLM_F_REQUEST); + + addattr_l(&req.n, 1024, CTRL_ATTR_FAMILY_NAME, + family, strlen(family) + 1); + + if (rtnl_talk(grth, &req.n, 0, 0, &req.n) < 0) { + fprintf(stderr, "Error talking to the kernel\n"); + return -2; + } + + return libgenl_parse_getfamily(&req.n); +} +
--
1.7.3.4