[libvirt] [PATCHv4 1/2] util: netlink: Introduce virNetlinkNewLink helper to simplify virNetDev*Create

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(a)massclouds.com&gt; --- 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