Subsequent patch needs to
(a) query and use socket family
(b) send/receive messages using this family
Hence add helper routines to open, close, query family and to perform
send receive operations.
Signed-off-by: Parav Pandit <parav@xxxxxxxxxx>
---
changelog:
v2->v3:
- split patch from add vdpa tool for socket helpers
---
include/mnl_utils.h | 16 ++++++
lib/mnl_utils.c | 121 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 137 insertions(+)
diff --git a/include/mnl_utils.h b/include/mnl_utils.h
index fa826ef1..9e7d6879 100644
--- a/include/mnl_utils.h
+++ b/include/mnl_utils.h
@@ -2,6 +2,22 @@
#ifndef __MNL_UTILS_H__
#define __MNL_UTILS_H__ 1
+struct mnlu_gen_socket {
+ struct mnl_socket *nl;
+ char *buf;
+ uint32_t family;
+ unsigned int seq;
+ uint8_t version;
+};
+
+int mnlu_gen_socket_open(struct mnlu_gen_socket *nlg, const char *family_name,
+ uint8_t version);
+void mnlu_gen_socket_close(struct mnlu_gen_socket *nlg);
+struct nlmsghdr *mnlu_gen_socket_cmd_prepare(struct mnlu_gen_socket *nlg,
+ uint8_t cmd, uint16_t flags);
+int mnlu_gen_socket_sndrcv(struct mnlu_gen_socket *nlg, const struct nlmsghdr *nlh,
+ mnl_cb_t data_cb, void *data);
+
struct mnl_socket *mnlu_socket_open(int bus);
struct nlmsghdr *mnlu_msg_prepare(void *buf, uint32_t nlmsg_type, uint16_t flags,
void *extra_header, size_t extra_header_size);
diff --git a/lib/mnl_utils.c b/lib/mnl_utils.c
index 46384ff8..4f699455 100644
--- a/lib/mnl_utils.c
+++ b/lib/mnl_utils.c
@@ -7,6 +7,7 @@
#include <string.h>
#include <time.h>
#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
#include "libnetlink.h"
#include "mnl_utils.h"
@@ -108,3 +109,123 @@ int mnlu_socket_recv_run(struct mnl_socket *nl, unsigned int seq, void *buf, siz
return err;
}
+
+static int get_family_id_attr_cb(const struct nlattr *attr, void *data)
+{
+ int type = mnl_attr_get_type(attr);
+ const struct nlattr **tb = data;
+
+ if (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) < 0)
+ return MNL_CB_ERROR;
+
+ if (type == CTRL_ATTR_FAMILY_ID &&
+ mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
+ return MNL_CB_ERROR;
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static int get_family_id_cb(const struct nlmsghdr *nlh, void *data)
+{
+ struct genlmsghdr *genl = mnl_nlmsg_get_payload(nlh);
+ struct nlattr *tb[CTRL_ATTR_MAX + 1] = {};
+ uint32_t *p_id = data;
+
+ mnl_attr_parse(nlh, sizeof(*genl), get_family_id_attr_cb, tb);
+ if (!tb[CTRL_ATTR_FAMILY_ID])
+ return MNL_CB_ERROR;
+ *p_id = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]);
+ return MNL_CB_OK;
+}
+
+static int family_get(struct mnlu_gen_socket *nlg, const char *family_name)
+{
+ struct genlmsghdr hdr = {};
+ struct nlmsghdr *nlh;
+ int err;
+
+ hdr.cmd = CTRL_CMD_GETFAMILY;
+ hdr.version = 0x1;
+
+ nlh = mnlu_msg_prepare(nlg->buf, GENL_ID_CTRL,
+ NLM_F_REQUEST | NLM_F_ACK,
+ &hdr, sizeof(hdr));
+
+ mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, family_name);
+
+ err = mnl_socket_sendto(nlg->nl, nlh, nlh->nlmsg_len);
+ if (err < 0)
+ return err;
+
+ err = mnlu_socket_recv_run(nlg->nl, nlh->nlmsg_seq, nlg->buf,
+ MNL_SOCKET_BUFFER_SIZE,
+ get_family_id_cb, &nlg->family);
+ return err;
+}
+
+int mnlu_gen_socket_open(struct mnlu_gen_socket *nlg, const char *family_name,
+ uint8_t version)
+{
+ int err;
+
+ nlg->buf = malloc(MNL_SOCKET_BUFFER_SIZE);
+ if (!nlg->buf)
+ goto err_buf_alloc;
+
+ nlg->nl = mnlu_socket_open(NETLINK_GENERIC);
+ if (!nlg->nl)
+ goto err_socket_open;
+
+ err = family_get(nlg, family_name);
+ if (err)
+ goto err_socket;
+
+ return 0;
+
+err_socket:
+ mnl_socket_close(nlg->nl);
+err_socket_open:
+ free(nlg->buf);
+err_buf_alloc:
+ return -1;
+}
+
+void mnlu_gen_socket_close(struct mnlu_gen_socket *nlg)
+{
+ mnl_socket_close(nlg->nl);
+ free(nlg->buf);
+}
+
+struct nlmsghdr *mnlu_gen_socket_cmd_prepare(struct mnlu_gen_socket *nlg,
+ uint8_t cmd, uint16_t flags)
+{
+ struct genlmsghdr hdr = {};
+ struct nlmsghdr *nlh;
+
+ hdr.cmd = cmd;
+ hdr.version = nlg->version;
+ nlh = mnlu_msg_prepare(nlg->buf, nlg->family, flags, &hdr, sizeof(hdr));
+ nlg->seq = nlh->nlmsg_seq;
+ return nlh;
+}
+
+int mnlu_gen_socket_sndrcv(struct mnlu_gen_socket *nlg, const struct nlmsghdr *nlh,
+ mnl_cb_t data_cb, void *data)
+{
+ int err;
+
+ err = mnl_socket_sendto(nlg->nl, nlh, nlh->nlmsg_len);
+ if (err < 0) {
+ perror("Failed to send data");
+ return -errno;
+ }
+
+ err = mnlu_socket_recv_run(nlg->nl, nlh->nlmsg_seq, nlg->buf,
+ MNL_SOCKET_BUFFER_SIZE,
+ data_cb, data);
+ if (err < 0) {
+ fprintf(stderr, "kernel answers: %s\n", strerror(errno));
+ return -errno;
+ }
+ return 0;
+}
--
2.26.2
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
