6:43 a.m.
On Thu, Aug 23, 2018 at 12:15:08PM +0800, Shi Lei wrote:
This patch adds virNetlinkNewLink for simplifying
virNetDevMacVLanCreate
and virNetDevBridgeCreate.
Signed-off-by: Shi Lei <shi_lei(a)massclouds.com>
---
There are multiple changes happening in this patch so it will need to be split
into several patches, see below...
src/libvirt_private.syms | 1 +
src/util/virnetdevbridge.c | 73 +++--------------------
src/util/virnetdevmacvlan.c | 137 ++++++++++++++------------------------------
src/util/virnetlink.c | 104 +++++++++++++++++++++++++++++++++
src/util/virnetlink.h | 8 +++
5 files changed, 164 insertions(+), 159 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 47ea35f..23931ba 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2439,6 +2439,7 @@ virNetlinkEventServiceStop;
virNetlinkEventServiceStopAll;
virNetlinkGetErrorCode;
virNetlinkGetNeighbor;
+virNetlinkNewLink;
virNetlinkShutdown;
virNetlinkStartup;
diff --git a/src/util/virnetdevbridge.c b/src/util/virnetdevbridge.c
index bc377b5..1f5b37e 100644
--- a/src/util/virnetdevbridge.c
+++ b/src/util/virnetdevbridge.c
@@ -417,77 +417,22 @@ 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;
+ int error = 0;
- 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;
-
- if (err->error < 0) {
+ if (virNetlinkNewLink(NULL, brname, NULL, type, NULL, 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);
- }
-# endif
-
- virReportSystemError(-err->error,
- _("error creating bridge interface %s"),
- brname);
- return -1;
+ if (error == -EOPNOTSUPP) {
+ /* fallback to ioctl if netlink doesn't support creating bridges */
+ return virNetDevBridgeCreateWithIoctl(brname);
}
- break;
+# endif
+ virReportSystemError(-error, _("error creating bridge interface %s"),
+ brname);
- 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..1629add 100644
--- a/src/util/virnetdevmacvlan.c
+++ b/src/util/virnetdevmacvlan.c
@@ -283,6 +283,37 @@ virNetDevMacVLanReleaseName(const char *name)
}
+static int
+virNetDevMacVLanCreateCallback(struct nl_msg *nl_msg, const void *opaque)
+{
+ const uint32_t *mode = (const uint32_t *) opaque;
+ if (!nl_msg || !opaque) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("nl_msg %p or opaque %p is NULL"),
+ nl_msg, opaque);
+ return -1;
+ }
+
+ if (*mode > 0) {
+ struct nlattr *info_data;
+ if (!(info_data = nla_nest_start(nl_msg, IFLA_INFO_DATA)))
+ goto buffer_too_small;
+
+ if (nla_put(nl_msg, IFLA_MACVLAN_MODE, sizeof(*mode), mode) < 0)
+ goto buffer_too_small;
+
+ nla_nest_end(nl_msg, info_data);
+ }
+
+ return 0;
+
+ buffer_too_small:
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("allocated netlink buffer is too small"));
+ return -1;
+}
Having a callback just to add a nested data into nl_msg doesn't feel like the
right approach, I'd expect a callback to do more specific stuff, this should be
special-cased in virNetlinkNewLink.
+
+
/**
* virNetDevMacVLanCreate:
*
@@ -307,113 +338,29 @@ virNetDevMacVLanCreate(const char *ifname,
uint32_t macvlan_mode,
int *retry)
{
^This replacement would be the last patch in the series.
- 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;
*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:
+ if (virNetlinkNewLink(&ifindex, ifname, macaddress, type,
+ virNetDevMacVLanCreateCallback, &macvlan_mode,
+ &error) < 0) {
+ char macstr[VIR_MAC_STRING_BUFLEN];
+ if (error == -EEXIST)
*retry = 1;
- goto cleanup;
-
- default:
- virReportSystemError(-err->error,
+ else
+ 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..817e347 100644
--- a/src/util/virnetlink.c
+++ b/src/util/virnetlink.c
@@ -489,6 +489,110 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
/**
+ * virNetlinkNewLink:
Introduction of this function should come in a separate patch before you start
replacing the existing ones.
+ *
+ * @ifindex: The index for the 'link' device
+ * @ifname: The name of the link
+ * @mac: The MAC address of the device
Most of ^these attributes could be packed into a virNetlinkNewLinkData
structure (or something similarly named). You'll have to test check for
VIR_DOMAIN_NET_TYPE_DIRECT and VIR_NETDEV_MACVLAN_MODE_VEPA according to my
comments below inside <comment_block>...
+ * @type: The type of device, i.e., "bridge",
"macvtap", "macvlan"
+ * @cb: The callback for filling in IFLA_INFO_DATA for this type
I don't think callback will be necessary
+ * @opaque: opaque for the callback
+ * @error: for retrieving error code
^see below for my comment on return value...
+ *
+ * Create a network "link" (aka interface aka device) with the given
+ * args. This works for many different types of network devices,
+ * including macvtap and bridges.
+ *
+ * Returns 0 on success, -1 on fatal error.
Since this is a nice libvirt wrapper around the netlink communication
machinery, I think that returning -<netlink_error> in case of an error is
reasonable. Then, each of the callers of this API can handle the return values
as they please.
+ */
+int
+virNetlinkNewLink(const int *ifindex,
+ const char *ifname,
+ const virMacAddr *mac,
+ const char *type,
+ virNetlinkNewLinkCallback cb,
+ const void *opaque,
+ int *error)
+{
+ struct nlmsgerr *err;
+ struct nlattr *linkinfo;
+ unsigned int buflen;
+ struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
+ VIR_AUTOPTR(virNetlinkMsg) nl_msg = NULL;
+ VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
+
+ *error = 0;
+
+ 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;
+
<comment_block>
+ if (ifindex && nla_put_u32(nl_msg, IFLA_LINK, *ifindex)
< 0)
pre-existing, but is there a particular reason why ^this has to be u32??
+ goto buffer_too_small;
+
+ if (mac && nla_put(nl_msg, IFLA_ADDRESS, VIR_MAC_BUFLEN, mac) < 0)
+ goto buffer_too_small;
Similarly, is there a reason why ^this is not necessary to be u32?
+
+ 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)))
Since we're already touching the code, I would find it more readable if ^this
was written as linkinfo = nla_nest_start. The reason for that is that it's not
immediately visible where the matching counterpart to "nla_nest_end" is.
+ goto buffer_too_small;
+
+ if (nla_put(nl_msg, IFLA_INFO_KIND, strlen(type), type) < 0)
I'm puzzled why ^this doesn't need strlen(foo)+1 instead of plain strlen(foo)
+ goto buffer_too_small;
</comment_block>
We could actually create a wrapper macro around nla_put which would make the
block (begin-end) tiny more readable. See my notes above, as I have further
questions...Now, the macros would again be a separate patch to make the change
more gradual. Depending on the comments to my questions above, the macro would
either take the size of the type and always call nla_put or a specialized
nla_put_<string|u32|whatever> function. I'm CC'ing Laine to help answering
my
questions inside <comment_block>.
Erik
+
+ if (cb && cb(nl_msg, opaque) < 0)
+ return -1;
+
+ nla_nest_end(nl_msg, linkinfo);
+
+ 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:
*
* @ifname: Name of the link
diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h
index 1e1e616..195c7bb 100644
--- a/src/util/virnetlink.h
+++ b/src/util/virnetlink.h
@@ -65,6 +65,14 @@ int virNetlinkDumpCommand(struct nl_msg *nl_msg,
unsigned int protocol, unsigned int groups,
void *opaque);
+typedef int (*virNetlinkNewLinkCallback)(struct nl_msg *nl_msg,
+ const void *opaque);
+
+int virNetlinkNewLink(const int *ifindex, const char *ifname,
+ const virMacAddr *macaddress, const char *type,
+ virNetlinkNewLinkCallback cb, const void *opaque,
+ int *error);
+
typedef int (*virNetlinkDelLinkFallback)(const char *ifname);
int virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback);
--
2.7.4
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