This is useful for iterating elements in a nested attribute,
if they're not parsed with a strict length limit or such.
Signed-off-by: Johannes Berg <[email protected]>
---
include/libnetlink.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/libnetlink.h b/include/libnetlink.h
index e27516f7648f..0d4a9f29afbd 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -284,4 +284,9 @@ int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
* messages from dump file */
#define NLMSG_TSTAMP 15
+#define rtattr_for_each_nested(attr, nest) \
+ for ((attr) = (void *)RTA_DATA(nest); \
+ RTA_OK(attr, RTA_PAYLOAD(nest) - ((char *)(attr) - (char *)RTA_DATA((nest)))); \
+ (attr) = RTA_TAIL((attr)))
+
#endif /* __LIBNETLINK_H__ */
--
2.26.2
Support dumping the netlink policy of a given generic netlink
family, the policy (with any sub-policies if appropriate) is
exported by the kernel in a general fashion.
Signed-off-by: Johannes Berg <[email protected]>
---
genl/ctrl.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/genl/ctrl.c b/genl/ctrl.c
index 0fb464b01cfb..68099fe97f1a 100644
--- a/genl/ctrl.c
+++ b/genl/ctrl.c
@@ -28,13 +28,15 @@
static int usage(void)
{
fprintf(stderr,"Usage: ctrl <CMD>\n" \
- "CMD := get <PARMS> | list | monitor\n" \
+ "CMD := get <PARMS> | list | monitor | policy <PARMS>\n" \
"PARMS := name <name> | id <id>\n" \
"Examples:\n" \
"\tctrl ls\n" \
"\tctrl monitor\n" \
"\tctrl get name foobar\n" \
- "\tctrl get id 0xF\n");
+ "\tctrl get id 0xF\n"
+ "\tctrl policy name foobar\n"
+ "\tctrl policy id 0xF\n");
return -1;
}
@@ -123,7 +125,8 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
ghdr->cmd != CTRL_CMD_DELFAMILY &&
ghdr->cmd != CTRL_CMD_NEWFAMILY &&
ghdr->cmd != CTRL_CMD_NEWMCAST_GRP &&
- ghdr->cmd != CTRL_CMD_DELMCAST_GRP) {
+ ghdr->cmd != CTRL_CMD_DELMCAST_GRP &&
+ ghdr->cmd != CTRL_CMD_GETPOLICY) {
fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
return 0;
}
@@ -136,7 +139,7 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
}
attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
- parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
+ parse_rtattr_flags(tb, CTRL_ATTR_MAX, attrs, len, NLA_F_NESTED);
if (tb[CTRL_ATTR_FAMILY_NAME]) {
char *name = RTA_DATA(tb[CTRL_ATTR_FAMILY_NAME]);
@@ -159,6 +162,9 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
__u32 *ma = RTA_DATA(tb[CTRL_ATTR_MAXATTR]);
fprintf(fp, " max attribs: %d ",*ma);
}
+ if (tb[CTRL_ATTR_POLICY])
+ nl_print_policy(tb[CTRL_ATTR_POLICY], fp);
+
/* end of family definitions .. */
fprintf(fp,"\n");
if (tb[CTRL_ATTR_OPS]) {
@@ -235,7 +241,9 @@ static int ctrl_list(int cmd, int argc, char **argv)
exit(1);
}
- if (cmd == CTRL_CMD_GETFAMILY) {
+ if (cmd == CTRL_CMD_GETFAMILY || cmd == CTRL_CMD_GETPOLICY) {
+ req.g.cmd = cmd;
+
if (argc != 2) {
fprintf(stderr, "Wrong number of params\n");
return -1;
@@ -260,7 +268,9 @@ static int ctrl_list(int cmd, int argc, char **argv)
fprintf(stderr, "Wrong params\n");
goto ctrl_done;
}
+ }
+ if (cmd == CTRL_CMD_GETFAMILY) {
if (rtnl_talk(&rth, nlh, &answer) < 0) {
fprintf(stderr, "Error talking to the kernel\n");
goto ctrl_done;
@@ -273,7 +283,7 @@ static int ctrl_list(int cmd, int argc, char **argv)
}
- if (cmd == CTRL_CMD_UNSPEC) {
+ if (cmd == CTRL_CMD_UNSPEC || cmd == CTRL_CMD_GETPOLICY) {
nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
nlh->nlmsg_seq = rth.dump = ++rth.seq;
@@ -324,6 +334,8 @@ static int parse_ctrl(struct genl_util *a, int argc, char **argv)
matches(*argv, "show") == 0 ||
matches(*argv, "lst") == 0)
return ctrl_list(CTRL_CMD_UNSPEC, argc-1, argv+1);
+ if (matches(*argv, "policy") == 0)
+ return ctrl_list(CTRL_CMD_GETPOLICY, argc-1, argv+1);
if (matches(*argv, "help") == 0)
return usage();
--
2.26.2
This prints out the data from the given nested attribute
to the given FILE pointer, interpreting the firmware that
the kernel has for showing netlink policies.
Signed-off-by: Johannes Berg <[email protected]>
---
include/libnetlink.h | 2 ++
lib/libnetlink.c | 73 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 75 insertions(+)
diff --git a/include/libnetlink.h b/include/libnetlink.h
index 0d4a9f29afbd..b9073a6a13ad 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -289,4 +289,6 @@ int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
RTA_OK(attr, RTA_PAYLOAD(nest) - ((char *)(attr) - (char *)RTA_DATA((nest)))); \
(attr) = RTA_TAIL((attr)))
+void nl_print_policy(const struct rtattr *attr, FILE *fp);
+
#endif /* __LIBNETLINK_H__ */
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index e02d6294b02e..a7b60d873afb 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -28,6 +28,7 @@
#include <linux/nexthop.h>
#include "libnetlink.h"
+#include "utils.h"
#define __aligned(x) __attribute__((aligned(x)))
@@ -1440,3 +1441,75 @@ int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
return 0;
}
+
+static const char *get_nla_type_str(unsigned int attr)
+{
+ switch (attr) {
+#define C(x) case NL_ATTR_TYPE_ ## x: return #x
+ C(U8);
+ C(U16);
+ C(U32);
+ C(U64);
+ C(STRING);
+ C(FLAG);
+ C(NESTED);
+ C(NESTED_ARRAY);
+ C(NUL_STRING);
+ C(BINARY);
+ C(S8);
+ C(S16);
+ C(S32);
+ C(S64);
+ C(BITFIELD32);
+ default:
+ return "unknown";
+ }
+}
+
+void nl_print_policy(const struct rtattr *attr, FILE *fp)
+{
+ const struct rtattr *pos;
+
+ rtattr_for_each_nested(pos, attr) {
+ const struct rtattr *attr;
+
+ fprintf(fp, " policy[%u]:", pos->rta_type & ~NLA_F_NESTED);
+
+ rtattr_for_each_nested(attr, pos) {
+ struct rtattr *tp[NL_POLICY_TYPE_ATTR_MAX + 1];
+
+ parse_rtattr_nested(tp, ARRAY_SIZE(tp) - 1, attr);
+
+ if (tp[NL_POLICY_TYPE_ATTR_TYPE])
+ fprintf(fp, "attr[%u]: type=%s",
+ attr->rta_type & ~NLA_F_NESTED,
+ get_nla_type_str(rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_TYPE])));
+
+ if (tp[NL_POLICY_TYPE_ATTR_POLICY_IDX])
+ fprintf(fp, " policy:%u",
+ rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_IDX]));
+
+ if (tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE])
+ fprintf(fp, " maxattr:%u",
+ rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE]));
+
+ if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S])
+ fprintf(fp, " range:[%lld,%lld]",
+ (signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S]),
+ (signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S]));
+
+ if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U])
+ fprintf(fp, " range:[%llu,%llu]",
+ (unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U]),
+ (unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U]));
+
+ if (tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH])
+ fprintf(fp, " min len:%u",
+ rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH]));
+
+ if (tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH])
+ fprintf(fp, " max len:%u",
+ rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH]));
+ }
+ }
+}
--
2.26.2
On 8/24/20 11:51 AM, Johannes Berg wrote:
> This is useful for iterating elements in a nested attribute,
> if they're not parsed with a strict length limit or such.
>
> Signed-off-by: Johannes Berg <[email protected]>
> ---
> include/libnetlink.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
applied to iproute2-next. Thanks, Johannes.
On Mon, 24 Aug 2020 19:51:07 +0200
Johannes Berg <[email protected]> wrote:
> This prints out the data from the given nested attribute
> to the given FILE pointer, interpreting the firmware that
> the kernel has for showing netlink policies.
>
> Signed-off-by: Johannes Berg <[email protected]>
This patch causes warnings from iproute2 build on Debian stable.
Please fix.
CC libnetlink.o
libnetlink.c:33: warning: "__aligned" redefined
#define __aligned(x) __attribute__((aligned(x)))
In file included from /usr/include/bsd/string.h:39,
from ../include/utils.h:13,
from libnetlink.c:31:
/usr/include/bsd/sys/cdefs.h:128: note: this is the location of the previous definition
# define __aligned(x) __attribute__((__aligned__(x)))