[libvirt] [PATCHv3 2/3] util: netlink: Add wrapper macros to make virNetlinkNewLink more readable
This patch adds wrapper macros around nla_nest_[start|end] and nla_put
which can make virNetlinkNewLink more readable.
Signed-off-by: Shi Lei <shi_lei(a)massclouds.com>
---
src/util/virnetlink.c | 43 +++++++++++++++----------------------------
src/util/virnetlink.h | 30 ++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+), 28 deletions(-)
diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
index d53cc73..99ad003 100644
--- a/src/util/virnetlink.c
+++ b/src/util/virnetlink.c
@@ -529,41 +529,33 @@ virNetlinkNewLink(const char *ifname,
return -ENOMEM;
}
- if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
- goto buffer_too_small;
+ if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("out of memory: nlmsg_append"));
+ return -ENOMEM;
+ }
- if (ifname && nla_put_string(nl_msg, IFLA_IFNAME, ifname) < 0)
- goto buffer_too_small;
+ NETLINK_MSG_PUT(nl_msg, IFLA_IFNAME, (strlen(ifname)+1), ifname);
- if (!(linkinfo = nla_nest_start(nl_msg, IFLA_LINKINFO)))
- goto buffer_too_small;
+ NETLINK_MSG_NEST_START(nl_msg, linkinfo, IFLA_LINKINFO);
- if (type && nla_put_string(nl_msg, IFLA_INFO_KIND, type) < 0)
- goto buffer_too_small;
+ NETLINK_MSG_PUT(nl_msg, IFLA_INFO_KIND, (strlen(type)+1), type);
if ((STREQ(type, "macvtap") || STREQ(type, "macvlan"))
&&
extra_args &&
extra_args->macvlan_mode &&
*extra_args->macvlan_mode > 0) {
- if (!(infodata = nla_nest_start(nl_msg, IFLA_INFO_DATA)))
- goto buffer_too_small;
-
- if (nla_put_u32(nl_msg, IFLA_MACVLAN_MODE, *extra_args->macvlan_mode) < 0)
- goto buffer_too_small;
-
- nla_nest_end(nl_msg, infodata);
+ NETLINK_MSG_NEST_START(nl_msg, infodata, IFLA_INFO_DATA);
+ NETLINK_MSG_PUT(nl_msg, IFLA_MACVLAN_MODE,
+ sizeof(uint32_t), extra_args->macvlan_mode);
+ NETLINK_MSG_NEST_END(nl_msg, infodata);
}
- nla_nest_end(nl_msg, linkinfo);
+ NETLINK_MSG_NEST_END(nl_msg, linkinfo);
if (extra_args) {
- if (extra_args->ifindex &&
- nla_put_u32(nl_msg, IFLA_LINK, *extra_args->ifindex) < 0)
- goto buffer_too_small;
-
- if (extra_args->mac &&
- nla_put(nl_msg, IFLA_ADDRESS, VIR_MAC_BUFLEN, extra_args->mac) < 0)
- goto buffer_too_small;
+ NETLINK_MSG_PUT(nl_msg, IFLA_LINK, sizeof(uint32_t), extra_args->ifindex);
+ NETLINK_MSG_PUT(nl_msg, IFLA_ADDRESS, VIR_MAC_BUFLEN, extra_args->mac);
}
if (virNetlinkCommand(nl_msg, &resp, &buflen, 0, 0, NETLINK_ROUTE, 0) <
0)
@@ -597,11 +589,6 @@ virNetlinkNewLink(const char *ifname,
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("malformed netlink response message"));
return -EBADMSG;
-
- buffer_too_small:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("allocated netlink buffer is too small"));
- return -ENOMEM;
}
diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h
index 09bab08..6f59d6e 100644
--- a/src/util/virnetlink.h
+++ b/src/util/virnetlink.h
@@ -48,6 +48,36 @@ struct nlmsghdr;
# endif /* __linux__ */
+
+# define NETLINK_MSG_NEST_START(msg, container, attrtype) \
+do { \
+ container = nla_nest_start(msg, attrtype); \
+ if (!container) { \
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", \
+ _("out of memory: nla_nest_start [" #attrtype
"]")); \
+ return -ENOMEM; \
+ } \
+} while(0)
+
+# define NETLINK_MSG_NEST_END(msg, container) \
+do { nla_nest_end(msg, container); } while(0)
+
+/*
+ * @data may be like &foo sometimes, therefore making compilers complain
+ * about the check below, so let's use an intermediary pointer type
+ * "the address of [...] will always evaluate as 'true'
[-Werror=address]"
+ */
+# define NETLINK_MSG_PUT(msg, attrtype, datalen, data) \
+do { \
+ const void *dataptr = data; \
+ if (dataptr && nla_put(msg, attrtype, datalen, dataptr) < 0) { \
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", \
+ _("out of memory: nla_put [" #attrtype "]"));
\
+ return -ENOMEM; \
+ } \
+} while(0)
+
+
int virNetlinkStartup(void);
void virNetlinkShutdown(void);
--
2.17.1