[libvirt] [PATCHv4 1/2] util: netlink: Introduce virNetlinkNewLink helper to simplify virNetDev*Create
Shi Lei
shi_lei at massclouds.com
Tue Sep 11 08:23:56 UTC 2018
This patch introduces virNetlinkNewLink helper which wraps the common
libnl/netlink code to create a new link.
The helper simplifies virNetDevBridgeCreate and virNetDevMacVLanCreate
by using virNetlinkNewLink.
Signed-off-by: Shi Lei <shi_lei at massclouds.com>
---
src/libvirt_private.syms | 1 +
src/util/virnetdevbridge.c | 73 +++------------------
src/util/virnetdevmacvlan.c | 110 +++++---------------------------
src/util/virnetlink.c | 124 ++++++++++++++++++++++++++++++++++++
src/util/virnetlink.h | 13 ++++
5 files changed, 162 insertions(+), 159 deletions(-)
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/virnetdevbridge.c b/src/util/virnetdevbridge.c
index bc377b5..ed2db27 100644
--- a/src/util/virnetdevbridge.c
+++ b/src/util/virnetdevbridge.c
@@ -416,78 +416,23 @@ int
virNetDevBridgeCreate(const char *brname)
{
/* use a netlink RTM_NEWLINK message to create the bridge */
- const char *type = "bridge";
- struct nlmsgerr *err;
- struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
- unsigned int recvbuflen;
- struct nlattr *linkinfo;
- VIR_AUTOPTR(virNetlinkMsg) nl_msg = NULL;
- VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
-
- nl_msg = nlmsg_alloc_simple(RTM_NEWLINK,
- NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
- if (!nl_msg) {
- virReportOOMError();
- return -1;
- }
-
- if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
- goto buffer_too_small;
- if (nla_put(nl_msg, IFLA_IFNAME, strlen(brname)+1, brname) < 0)
- goto buffer_too_small;
- if (!(linkinfo = nla_nest_start(nl_msg, IFLA_LINKINFO)))
- goto buffer_too_small;
- if (nla_put(nl_msg, IFLA_INFO_KIND, strlen(type), type) < 0)
- goto buffer_too_small;
- nla_nest_end(nl_msg, linkinfo);
-
- if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0,
- NETLINK_ROUTE, 0) < 0) {
- return -1;
- }
-
- if (recvbuflen < 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;
+ int error = 0;
- if (err->error < 0) {
+ if (virNetlinkNewLink(brname, "bridge", NULL, &error) < 0) {
# if defined(HAVE_STRUCT_IFREQ) && defined(SIOCBRADDBR)
- if (err->error == -EOPNOTSUPP) {
- /* fallback to ioctl if netlink doesn't support creating
- * bridges
- */
- return virNetDevBridgeCreateWithIoctl(brname);
- }
+ if (error == -EOPNOTSUPP) {
+ /* fallback to ioctl if netlink doesn't support creating bridges */
+ return virNetDevBridgeCreateWithIoctl(brname);
+ }
# endif
-
- virReportSystemError(-err->error,
- _("error creating bridge interface %s"),
+ if (error < 0)
+ virReportSystemError(-error, _("error creating bridge interface %s"),
brname);
- return -1;
- }
- break;
- case NLMSG_DONE:
- break;
- default:
- goto malformed_resp;
+ return -1;
}
return 0;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- return -1;
- buffer_too_small:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("allocated netlink buffer is too small"));
- return -1;
}
diff --git a/src/util/virnetdevmacvlan.c b/src/util/virnetdevmacvlan.c
index 2035b1f..a66ab59 100644
--- a/src/util/virnetdevmacvlan.c
+++ b/src/util/virnetdevmacvlan.c
@@ -307,113 +307,33 @@ virNetDevMacVLanCreate(const char *ifname,
uint32_t macvlan_mode,
int *retry)
{
- int rc = -1;
- struct nlmsgerr *err;
- struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
- int ifindex;
- unsigned int recvbuflen;
- struct nl_msg *nl_msg;
- struct nlattr *linkinfo, *info_data;
- char macstr[VIR_MAC_STRING_BUFLEN];
- VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
-
- if (virNetDevGetIndex(srcdev, &ifindex) < 0)
- return -1;
+ int error = 0;
+ int ifindex = 0;
+ virNetlinkNewLinkData data = {
+ .macvlan_mode = &macvlan_mode,
+ .mac = macaddress,
+ };
*retry = 0;
- nl_msg = nlmsg_alloc_simple(RTM_NEWLINK,
- NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
- if (!nl_msg) {
- virReportOOMError();
+ if (virNetDevGetIndex(srcdev, &ifindex) < 0)
return -1;
- }
-
- if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
- goto buffer_too_small;
-
- if (nla_put_u32(nl_msg, IFLA_LINK, ifindex) < 0)
- goto buffer_too_small;
-
- if (nla_put(nl_msg, IFLA_ADDRESS, VIR_MAC_BUFLEN, macaddress) < 0)
- goto buffer_too_small;
-
- if (ifname &&
- nla_put(nl_msg, IFLA_IFNAME, strlen(ifname)+1, ifname) < 0)
- goto buffer_too_small;
-
- if (!(linkinfo = nla_nest_start(nl_msg, IFLA_LINKINFO)))
- goto buffer_too_small;
-
- if (nla_put(nl_msg, IFLA_INFO_KIND, strlen(type), type) < 0)
- goto buffer_too_small;
-
- if (macvlan_mode > 0) {
- if (!(info_data = nla_nest_start(nl_msg, IFLA_INFO_DATA)))
- goto buffer_too_small;
-
- if (nla_put(nl_msg, IFLA_MACVLAN_MODE, sizeof(macvlan_mode),
- &macvlan_mode) < 0)
- goto buffer_too_small;
-
- nla_nest_end(nl_msg, info_data);
- }
- nla_nest_end(nl_msg, linkinfo);
-
- if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0,
- NETLINK_ROUTE, 0) < 0) {
- goto cleanup;
- }
-
- if (recvbuflen < 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;
-
- switch (err->error) {
-
- case 0:
- break;
-
- case -EEXIST:
+ data.ifindex = &ifindex;
+ if (virNetlinkNewLink(ifname, type, &data, &error) < 0) {
+ char macstr[VIR_MAC_STRING_BUFLEN];
+ if (error == -EEXIST)
*retry = 1;
- goto cleanup;
-
- default:
- virReportSystemError(-err->error,
+ else if (error < 0)
+ virReportSystemError(-error,
_("error creating %s interface %s@%s (%s)"),
type, ifname, srcdev,
virMacAddrFormat(macaddress, macstr));
- goto cleanup;
- }
- break;
-
- case NLMSG_DONE:
- break;
- default:
- goto malformed_resp;
+ return -1;
}
- rc = 0;
- cleanup:
- nlmsg_free(nl_msg);
- return rc;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- goto cleanup;
-
- buffer_too_small:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("allocated netlink buffer is too small"));
- goto cleanup;
+ return 0;
}
/**
diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
index 8f06446..815bbee 100644
--- a/src/util/virnetlink.c
+++ b/src/util/virnetlink.c
@@ -488,6 +488,130 @@ 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, -1 on error. Additionally, if the @error is
+ * non-zero, then the failure occurred during virNetlinkCommand, but
+ * no error message is generated leaving it up to the caller to handle
+ * the condition.
+ */
+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",
+ _("either interface name or type is missing"));
+ return -1;
+ }
+
+ VIR_DEBUG("Create network link ifname=%s, type=%s", ifname, type);
+
+ nl_msg = nlmsg_alloc_simple(RTM_NEWLINK,
+ NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
+ if (!nl_msg) {
+ virReportOOMError();
+ return -1;
+ }
+
+ if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
+ goto buffer_too_small;
+
+ if (ifname && nla_put(nl_msg, IFLA_IFNAME, strlen(ifname)+1, ifname) < 0)
+ goto buffer_too_small;
+
+ if (!(linkinfo = nla_nest_start(nl_msg, IFLA_LINKINFO)))
+ goto buffer_too_small;
+
+ if (type && nla_put(nl_msg, IFLA_INFO_KIND, strlen(type)+1, 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(nl_msg, IFLA_MACVLAN_MODE, sizeof(uint32_t),
+ 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(nl_msg, IFLA_LINK, sizeof(uint32_t),
+ 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 -1;
+
+ buffer_too_small:
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("allocated netlink buffer is too small"));
+ return -1;
+}
+
+
/**
* 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
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