[PATCH 4/4] netlink: Introduce a helper function to simplify netlink functions
Shi Lei
shi_lei at massclouds.com
Mon Dec 21 03:23:50 UTC 2020
Extract common code as helper function virNetlinkTalk, then simplify
the functions virNetlink[DumpLink|NewLink|DelLink|GetNeighbor].
Signed-off-by: Shi Lei <shi_lei at massclouds.com>
---
src/util/virnetlink.c | 210 +++++++++++++++---------------------------
src/util/virnetlink.h | 4 +-
2 files changed, 78 insertions(+), 136 deletions(-)
diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
index fdcb0dc0..7bea38c0 100644
--- a/src/util/virnetlink.c
+++ b/src/util/virnetlink.c
@@ -353,6 +353,48 @@ int virNetlinkCommand(struct nl_msg *nl_msg,
return 0;
}
+
+static int
+virNetlinkTalk(const char *ifname,
+ virNetlinkMsg *nl_msg,
+ uint32_t src_pid,
+ uint32_t dst_pid,
+ struct nlmsghdr **resp,
+ unsigned int *resp_len,
+ int *error,
+ virNetlinkTalkFallback fallback)
+{
+ if (virNetlinkCommand(nl_msg, resp, resp_len,
+ src_pid, dst_pid, NETLINK_ROUTE, 0) < 0)
+ return -1;
+
+ if (*resp_len < NLMSG_LENGTH(0) || resp == NULL)
+ goto malformed_resp;
+
+ if ((*resp)->nlmsg_type == NLMSG_ERROR) {
+ struct nlmsgerr *err = (struct nlmsgerr *) NLMSG_DATA(resp);
+ if ((*resp)->nlmsg_len < NLMSG_LENGTH(sizeof(*err)))
+ goto malformed_resp;
+
+ if (-err->error == EOPNOTSUPP && fallback)
+ return fallback(ifname);
+
+ if (err->error < 0) {
+ if (error)
+ *error = err->error;
+ return -1;
+ }
+ }
+
+ return 0;
+
+ malformed_resp:
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ return -1;
+}
+
+
int
virNetlinkDumpCommand(struct nl_msg *nl_msg,
virNetlinkDumpCallback callback,
@@ -396,6 +438,7 @@ virNetlinkDumpCommand(struct nl_msg *nl_msg,
return 0;
}
+
/**
* virNetlinkDumpLink:
*
@@ -420,15 +463,13 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
void **nlData, struct nlattr **tb,
uint32_t src_pid, uint32_t dst_pid)
{
- int rc = -1;
- struct nlmsgerr *err;
struct ifinfomsg ifinfo = {
.ifi_family = AF_UNSPEC,
.ifi_index = ifindex
};
- unsigned int recvbuflen;
g_autoptr(virNetlinkMsg) nl_msg = NULL;
g_autofree struct nlmsghdr *resp = NULL;
+ unsigned int resp_len = 0;
if (ifname && ifindex <= 0 && virNetDevGetIndex(ifname, &ifindex) < 0)
return -1;
@@ -459,46 +500,19 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
}
# endif
- if (virNetlinkCommand(nl_msg, &resp, &recvbuflen,
- src_pid, dst_pid, NETLINK_ROUTE, 0) < 0)
+ if (virNetlinkTalk(ifname, nl_msg, src_pid, dst_pid,
+ &resp, &resp_len, NULL, NULL) < 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) {
- virReportSystemError(-err->error,
- _("error dumping %s (%d) interface"),
- ifname, ifindex);
- return -1;
- }
- break;
-
- case GENL_ID_CTRL:
- case NLMSG_DONE:
- rc = nlmsg_parse(resp, sizeof(struct ifinfomsg),
- tb, IFLA_MAX, NULL);
- if (rc < 0)
- goto malformed_resp;
- break;
-
- default:
- goto malformed_resp;
+ if ((resp->nlmsg_type != GENL_ID_CTRL && resp->nlmsg_type != NLMSG_DONE) ||
+ nlmsg_parse(resp, sizeof(struct ifinfomsg), tb, IFLA_MAX, NULL) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ return -1;
}
*nlData = g_steal_pointer(&resp);
return 0;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- return rc;
}
@@ -523,13 +537,12 @@ virNetlinkNewLink(const char *ifname,
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 };
g_autoptr(virNetlinkMsg) nl_msg = NULL;
g_autofree struct nlmsghdr *resp = NULL;
+ unsigned int resp_len = 0;
*error = 0;
@@ -591,37 +604,17 @@ virNetlinkNewLink(const char *ifname,
}
}
- if (virNetlinkCommand(nl_msg, &resp, &buflen, 0, 0, NETLINK_ROUTE, 0) < 0)
+ if (virNetlinkTalk(ifname, nl_msg, 0, 0,
+ &resp, &resp_len, error, NULL) < 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;
+ if (resp->nlmsg_type != NLMSG_DONE) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ return -1;
}
return 0;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- return -1;
}
@@ -641,13 +634,12 @@ virNetlinkNewLink(const char *ifname,
* Returns 0 on success, -1 on fatal error.
*/
int
-virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback)
+virNetlinkDelLink(const char *ifname, virNetlinkTalkFallback fallback)
{
- struct nlmsgerr *err;
struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
- unsigned int recvbuflen;
g_autoptr(virNetlinkMsg) nl_msg = NULL;
g_autofree struct nlmsghdr *resp = NULL;
+ unsigned int resp_len = 0;
nl_msg = nlmsg_alloc_simple(RTM_DELLINK, NLM_F_REQUEST);
if (!nl_msg) {
@@ -659,44 +651,17 @@ virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback)
NETLINK_MSG_PUT(nl_msg, IFLA_IFNAME, (strlen(ifname) + 1), ifname);
- if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0,
- NETLINK_ROUTE, 0) < 0) {
+ if (virNetlinkTalk(ifname, nl_msg, 0, 0,
+ &resp, &resp_len, NULL, fallback) < 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 == EOPNOTSUPP && fallback)
- return fallback(ifname);
-
- if (err->error) {
- virReportSystemError(-err->error,
- _("error destroying network device %s"),
- ifname);
- return -1;
- }
- break;
-
- case NLMSG_DONE:
- break;
-
- default:
- goto malformed_resp;
+ if (resp->nlmsg_type != NLMSG_DONE) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ return -1;
}
return 0;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- return -1;
}
/**
@@ -712,18 +677,17 @@ virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback)
*
* Get neighbor table entry from netlink.
*
- * Returns 0 on success, -1 on fatal error.
+ * Returns length of the raw data from netlink on success, -1 on fatal error.
*/
int
virNetlinkGetNeighbor(void **nlData, uint32_t src_pid, uint32_t dst_pid)
{
- struct nlmsgerr *err;
struct ndmsg ndinfo = {
.ndm_family = AF_UNSPEC,
};
- unsigned int recvbuflen;
g_autoptr(virNetlinkMsg) nl_msg = NULL;
g_autofree struct nlmsghdr *resp = NULL;
+ unsigned int resp_len = 0;
nl_msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_DUMP | NLM_F_REQUEST);
if (!nl_msg) {
@@ -733,40 +697,18 @@ virNetlinkGetNeighbor(void **nlData, uint32_t src_pid, uint32_t dst_pid)
NETLINK_MSG_APPEND(nl_msg, sizeof(ndinfo), &ndinfo);
- if (virNetlinkCommand(nl_msg, &resp, &recvbuflen,
- src_pid, dst_pid, NETLINK_ROUTE, 0) < 0)
+ if (virNetlinkTalk(NULL, nl_msg, src_pid, dst_pid,
+ &resp, &resp_len, NULL, NULL) < 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) {
- virReportSystemError(-err->error,
- "%s", _("error dumping"));
- return -1;
- }
- break;
-
- case RTM_NEWNEIGH:
- break;
-
- default:
- goto malformed_resp;
+ if (resp->nlmsg_type != RTM_NEWNEIGH) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ return -1;
}
*nlData = g_steal_pointer(&resp);
- return recvbuflen;
-
- malformed_resp:
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("malformed netlink response message"));
- return -1;
+ return resp_len;
}
int
@@ -1300,7 +1242,7 @@ virNetlinkDumpLink(const char *ifname G_GNUC_UNUSED,
int
virNetlinkDelLink(const char *ifname G_GNUC_UNUSED,
- virNetlinkDelLinkFallback fallback G_GNUC_UNUSED)
+ virNetlinkTalkFallback fallback G_GNUC_UNUSED)
{
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _(unsupported));
return -1;
diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h
index 966d6db3..cab685fe 100644
--- a/src/util/virnetlink.h
+++ b/src/util/virnetlink.h
@@ -69,9 +69,9 @@ int virNetlinkNewLink(const char *ifname,
virNetlinkNewLinkDataPtr data,
int *error);
-typedef int (*virNetlinkDelLinkFallback)(const char *ifname);
+typedef int (*virNetlinkTalkFallback)(const char *ifname);
-int virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback);
+int virNetlinkDelLink(const char *ifname, virNetlinkTalkFallback fallback);
int virNetlinkGetErrorCode(struct nlmsghdr *resp, unsigned int recvbuflen);
--
2.25.1
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