diff options
Diffstat (limited to 'tools/net/ynl/lib/ynl-priv.h')
-rw-r--r-- | tools/net/ynl/lib/ynl-priv.h | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/tools/net/ynl/lib/ynl-priv.h b/tools/net/ynl/lib/ynl-priv.h index a8099fab035d..6cf890080dc0 100644 --- a/tools/net/ynl/lib/ynl-priv.h +++ b/tools/net/ynl/lib/ynl-priv.h @@ -135,6 +135,8 @@ int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg); /* Netlink message handling helpers */ +#define YNL_MSG_OVERFLOW 1 + static inline struct nlmsghdr *ynl_nlmsg_put_header(void *buf) { struct nlmsghdr *nlh = buf; @@ -239,11 +241,29 @@ ynl_attr_first(const void *start, size_t len, size_t skip) return ynl_attr_if_good(start + len, attr); } +static inline bool +__ynl_attr_put_overflow(struct nlmsghdr *nlh, size_t size) +{ + bool o; + + /* ynl_msg_start() stashed buffer length in nlmsg_pid. */ + o = nlh->nlmsg_len + NLA_HDRLEN + NLMSG_ALIGN(size) > nlh->nlmsg_pid; + if (o) + /* YNL_MSG_OVERFLOW is < NLMSG_HDRLEN, all subsequent checks + * are guaranteed to fail. + */ + nlh->nlmsg_pid = YNL_MSG_OVERFLOW; + return o; +} + static inline struct nlattr * ynl_attr_nest_start(struct nlmsghdr *nlh, unsigned int attr_type) { struct nlattr *attr; + if (__ynl_attr_put_overflow(nlh, 0)) + return ynl_nlmsg_end_addr(nlh) - NLA_HDRLEN; + attr = ynl_nlmsg_end_addr(nlh); attr->nla_type = attr_type | NLA_F_NESTED; nlh->nlmsg_len += NLA_HDRLEN; @@ -263,6 +283,9 @@ ynl_attr_put(struct nlmsghdr *nlh, unsigned int attr_type, { struct nlattr *attr; + if (__ynl_attr_put_overflow(nlh, size)) + return; + attr = ynl_nlmsg_end_addr(nlh); attr->nla_type = attr_type; attr->nla_len = NLA_HDRLEN + size; @@ -276,14 +299,17 @@ static inline void ynl_attr_put_str(struct nlmsghdr *nlh, unsigned int attr_type, const char *str) { struct nlattr *attr; - const char *end; + size_t len; + + len = strlen(str); + if (__ynl_attr_put_overflow(nlh, len)) + return; attr = ynl_nlmsg_end_addr(nlh); attr->nla_type = attr_type; - end = stpcpy(ynl_attr_data(attr), str); - attr->nla_len = - NLA_HDRLEN + NLA_ALIGN(end - (char *)ynl_attr_data(attr)); + strcpy(ynl_attr_data(attr), str); + attr->nla_len = NLA_HDRLEN + NLA_ALIGN(len); nlh->nlmsg_len += NLMSG_ALIGN(attr->nla_len); } |