libnetlink: Fix extack attribute parsing

Initialize tb in nl_dump_ext_err since not all attributes will be
sent in the messages.

Add error checking on mnl_attr_parse and print messages on the off
chance the ext ack attributes fail to validate.

Signed-off-by: David Ahern <dsahern@gmail.com>
This commit is contained in:
David Ahern 2017-08-17 13:43:00 -07:00 committed by Stephen Hemminger
parent 8cc360fe48
commit e5fa0e6fe7

View File

@ -49,13 +49,17 @@ static int err_attr_cb(const struct nlattr *attr, void *data)
const struct nlattr **tb = data;
uint16_t type;
if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0)
if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) {
fprintf(stderr, "Invalid extack attribute\n");
return MNL_CB_ERROR;
}
type = mnl_attr_get_type(attr);
if (mnl_attr_validate(attr, extack_policy[type]) < 0)
if (mnl_attr_validate(attr, extack_policy[type]) < 0) {
fprintf(stderr, "extack attribute %d failed validation\n",
type);
return MNL_CB_ERROR;
}
tb[type] = attr;
return MNL_CB_OK;
@ -64,7 +68,7 @@ static int err_attr_cb(const struct nlattr *attr, void *data)
/* dump netlink extended ack error message */
static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
{
struct nlattr *tb[NLMSGERR_ATTR_MAX + 1];
struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
const struct nlmsghdr *err_nlh = NULL;
unsigned int hlen = sizeof(*err);
@ -79,7 +83,8 @@ static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
hlen += mnl_nlmsg_get_payload_len(&err->msg);
mnl_attr_parse(nlh, hlen, err_attr_cb, tb);
if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
return 0;
if (tb[NLMSGERR_ATTR_MSG])
errmsg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);