2:17 a.m.
This patch introduces virNetlinkNewLink helper which wraps the common
libnl/netlink code to create a new link.
Signed-off-by: Shi Lei <shi_lei(a)massclouds.com>
---
src/libvirt_private.syms | 1 +
src/util/virnetlink.c | 117 +++++++++++++++++++++++++++++++++++++++
src/util/virnetlink.h | 13 +++++
3 files changed, 131 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 0fc5314..a0d229a 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2446,6 +2446,7 @@ virNetlinkEventServiceStop;
virNetlinkEventServiceStopAll;
virNetlinkGetErrorCode;
virNetlinkGetNeighbor;
+virNetlinkNewLink;
virNetlinkShutdown;
virNetlinkStartup;
diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
index 8f06446..d53cc73 100644
--- a/src/util/virnetlink.c
+++ b/src/util/virnetlink.c
@@ -488,6 +488,123 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
}
+/**
+ * virNetlinkNewLink:
+ *
+ * @ifname: name of the link
+ * @type: the type of the device, i.e. "bridge", "macvtap",
"macvlan"
+ * @extra_args: the extra args for creating the netlink interface
+ * @error: netlink error code
+ *
+ * A generic wrapper to create a network link.
+ *
+ * Returns 0 on success, < 0 on fatal error.
+ */
+int
+virNetlinkNewLink(const char *ifname,
+ const char *type,
+ virNetlinkNewLinkDataPtr extra_args,
+ int *error)
+{
+ struct nlmsgerr *err;
+ struct nlattr *linkinfo = NULL;
+ struct nlattr *infodata = NULL;
+ unsigned int buflen;
+ struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
+ VIR_AUTOPTR(virNetlinkMsg) nl_msg = NULL;
+ VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
+
+ *error = 0;
+
+ if (!ifname || !type) {
+ virReportError(VIR_ERR_INVALID_ARG, "%s",
+ _("neither of name and type can be NULL"));
+ return -EINVAL;
+ }
+
+ nl_msg = nlmsg_alloc_simple(RTM_NEWLINK,
+ NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
+ if (!nl_msg) {
+ virReportOOMError();
+ return -ENOMEM;
+ }
+
+ if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
+ goto buffer_too_small;
+
+ if (ifname && nla_put_string(nl_msg, IFLA_IFNAME, ifname) < 0)
+ goto buffer_too_small;
+
+ if (!(linkinfo = nla_nest_start(nl_msg, IFLA_LINKINFO)))
+ goto buffer_too_small;
+
+ if (type && nla_put_string(nl_msg, IFLA_INFO_KIND, type) < 0)
+ goto buffer_too_small;
+
+ 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);
+ }
+
+ nla_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;
+ }
+
+ if (virNetlinkCommand(nl_msg, &resp, &buflen, 0, 0, NETLINK_ROUTE, 0) <
0)
+ return -1;
+
+ if (buflen < NLMSG_LENGTH(0) || resp == NULL)
+ goto malformed_resp;
+
+ switch (resp->nlmsg_type) {
+ case NLMSG_ERROR:
+ err = (struct nlmsgerr *)NLMSG_DATA(resp);
+ if (resp->nlmsg_len < NLMSG_LENGTH(sizeof(*err)))
+ goto malformed_resp;
+
+ if (err->error < 0) {
+ *error = err->error;
+ return -1;
+ }
+ break;
+
+ case NLMSG_DONE:
+ break;
+
+ default:
+ goto malformed_resp;
+ }
+
+ return 0;
+
+ malformed_resp:
+ 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;
+}
+
+
/**
* virNetlinkDelLink:
*
diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h
index 1e1e616..09bab08 100644
--- a/src/util/virnetlink.h
+++ b/src/util/virnetlink.h
@@ -65,6 +65,19 @@ int virNetlinkDumpCommand(struct nl_msg *nl_msg,
unsigned int protocol, unsigned int groups,
void *opaque);
+typedef struct _virNetlinkNewLinkData virNetlinkNewLinkData;
+typedef virNetlinkNewLinkData *virNetlinkNewLinkDataPtr;
+struct _virNetlinkNewLinkData {
+ const int *ifindex; /* The index for the 'link' device */
+ const virMacAddr *mac; /* The MAC address of the device */
+ const uint32_t *macvlan_mode; /* The mode of macvlan */
+};
+
+int virNetlinkNewLink(const char *ifname,
+ const char *type,
+ virNetlinkNewLinkDataPtr data,
+ int *error);
+
typedef int (*virNetlinkDelLinkFallback)(const char *ifname);
int virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback);
--
2.17.1