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-rw-r--r--src/netlink.h785
1 files changed, 785 insertions, 0 deletions
diff --git a/src/netlink.h b/src/netlink.h
new file mode 100644
index 0000000..2e36369
--- /dev/null
+++ b/src/netlink.h
@@ -0,0 +1,785 @@
+// SPDX-License-Identifier: LGPL-2.1+
+/*
+ * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * Copyright (C) 2008-2012 Pablo Neira Ayuso <pablo@netfilter.org>.
+ */
+
+/* This is a minimized version of libmnl meant to be #include'd */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <linux/netlink.h>
+#include <linux/genetlink.h>
+
+#define MNL_SOCKET_AUTOPID 0
+#define MNL_SOCKET_BUFFER_SIZE (sysconf(_SC_PAGESIZE) < 8192L ? sysconf(_SC_PAGESIZE) : 8192L)
+#define MNL_ALIGNTO 4
+#define MNL_ALIGN(len) (((len)+MNL_ALIGNTO-1) & ~(MNL_ALIGNTO-1))
+#define MNL_NLMSG_HDRLEN MNL_ALIGN(sizeof(struct nlmsghdr))
+#define MNL_ATTR_HDRLEN MNL_ALIGN(sizeof(struct nlattr))
+
+enum mnl_attr_data_type {
+ MNL_TYPE_UNSPEC,
+ MNL_TYPE_U8,
+ MNL_TYPE_U16,
+ MNL_TYPE_U32,
+ MNL_TYPE_U64,
+ MNL_TYPE_STRING,
+ MNL_TYPE_FLAG,
+ MNL_TYPE_MSECS,
+ MNL_TYPE_NESTED,
+ MNL_TYPE_NESTED_COMPAT,
+ MNL_TYPE_NUL_STRING,
+ MNL_TYPE_BINARY,
+ MNL_TYPE_MAX,
+};
+
+#define mnl_attr_for_each(attr, nlh, offset) \
+ for ((attr) = mnl_nlmsg_get_payload_offset((nlh), (offset)); \
+ mnl_attr_ok((attr), (char *)mnl_nlmsg_get_payload_tail(nlh) - (char *)(attr)); \
+ (attr) = mnl_attr_next(attr))
+
+#define mnl_attr_for_each_nested(attr, nest) \
+ for ((attr) = mnl_attr_get_payload(nest); \
+ mnl_attr_ok((attr), (char *)mnl_attr_get_payload(nest) + mnl_attr_get_payload_len(nest) - (char *)(attr)); \
+ (attr) = mnl_attr_next(attr))
+
+#define mnl_attr_for_each_payload(payload, payload_size) \
+ for ((attr) = (payload); \
+ mnl_attr_ok((attr), (char *)(payload) + payload_size - (char *)(attr)); \
+ (attr) = mnl_attr_next(attr))
+
+#define MNL_CB_ERROR -1
+#define MNL_CB_STOP 0
+#define MNL_CB_OK 1
+
+typedef int (*mnl_attr_cb_t)(const struct nlattr *attr, void *data);
+typedef int (*mnl_cb_t)(const struct nlmsghdr *nlh, void *data);
+
+#ifndef MNL_ARRAY_SIZE
+#define MNL_ARRAY_SIZE(a) (sizeof(a)/sizeof((a)[0]))
+#endif
+
+static size_t mnl_nlmsg_size(size_t len)
+{
+ return len + MNL_NLMSG_HDRLEN;
+}
+
+static struct nlmsghdr *mnl_nlmsg_put_header(void *buf)
+{
+ int len = MNL_ALIGN(sizeof(struct nlmsghdr));
+ struct nlmsghdr *nlh = buf;
+
+ memset(buf, 0, len);
+ nlh->nlmsg_len = len;
+ return nlh;
+}
+
+static void *mnl_nlmsg_put_extra_header(struct nlmsghdr *nlh, size_t size)
+{
+ char *ptr = (char *)nlh + nlh->nlmsg_len;
+ size_t len = MNL_ALIGN(size);
+ nlh->nlmsg_len += len;
+ memset(ptr, 0, len);
+ return ptr;
+}
+
+static void *mnl_nlmsg_get_payload(const struct nlmsghdr *nlh)
+{
+ return (void *)nlh + MNL_NLMSG_HDRLEN;
+}
+
+static void *mnl_nlmsg_get_payload_offset(const struct nlmsghdr *nlh, size_t offset)
+{
+ return (void *)nlh + MNL_NLMSG_HDRLEN + MNL_ALIGN(offset);
+}
+
+static bool mnl_nlmsg_ok(const struct nlmsghdr *nlh, int len)
+{
+ return len >= (int)sizeof(struct nlmsghdr) &&
+ nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
+ (int)nlh->nlmsg_len <= len;
+}
+
+static struct nlmsghdr *mnl_nlmsg_next(const struct nlmsghdr *nlh, int *len)
+{
+ *len -= MNL_ALIGN(nlh->nlmsg_len);
+ return (struct nlmsghdr *)((void *)nlh + MNL_ALIGN(nlh->nlmsg_len));
+}
+
+static void *mnl_nlmsg_get_payload_tail(const struct nlmsghdr *nlh)
+{
+ return (void *)nlh + MNL_ALIGN(nlh->nlmsg_len);
+}
+
+static bool mnl_nlmsg_seq_ok(const struct nlmsghdr *nlh, unsigned int seq)
+{
+ return nlh->nlmsg_seq && seq ? nlh->nlmsg_seq == seq : true;
+}
+
+static bool mnl_nlmsg_portid_ok(const struct nlmsghdr *nlh, unsigned int portid)
+{
+ return nlh->nlmsg_pid && portid ? nlh->nlmsg_pid == portid : true;
+}
+
+static uint16_t mnl_attr_get_type(const struct nlattr *attr)
+{
+ return attr->nla_type & NLA_TYPE_MASK;
+}
+
+static uint16_t mnl_attr_get_payload_len(const struct nlattr *attr)
+{
+ return attr->nla_len - MNL_ATTR_HDRLEN;
+}
+
+static void *mnl_attr_get_payload(const struct nlattr *attr)
+{
+ return (void *)attr + MNL_ATTR_HDRLEN;
+}
+
+static bool mnl_attr_ok(const struct nlattr *attr, int len)
+{
+ return len >= (int)sizeof(struct nlattr) &&
+ attr->nla_len >= sizeof(struct nlattr) &&
+ (int)attr->nla_len <= len;
+}
+
+static struct nlattr *mnl_attr_next(const struct nlattr *attr)
+{
+ return (struct nlattr *)((void *)attr + MNL_ALIGN(attr->nla_len));
+}
+
+static int mnl_attr_type_valid(const struct nlattr *attr, uint16_t max)
+{
+ if (mnl_attr_get_type(attr) > max) {
+ errno = EOPNOTSUPP;
+ return -1;
+ }
+ return 1;
+}
+
+static int __mnl_attr_validate(const struct nlattr *attr,
+ enum mnl_attr_data_type type, size_t exp_len)
+{
+ uint16_t attr_len = mnl_attr_get_payload_len(attr);
+ const char *attr_data = mnl_attr_get_payload(attr);
+
+ if (attr_len < exp_len) {
+ errno = ERANGE;
+ return -1;
+ }
+ switch(type) {
+ case MNL_TYPE_FLAG:
+ if (attr_len > 0) {
+ errno = ERANGE;
+ return -1;
+ }
+ break;
+ case MNL_TYPE_NUL_STRING:
+ if (attr_len == 0) {
+ errno = ERANGE;
+ return -1;
+ }
+ if (attr_data[attr_len-1] != '\0') {
+ errno = EINVAL;
+ return -1;
+ }
+ break;
+ case MNL_TYPE_STRING:
+ if (attr_len == 0) {
+ errno = ERANGE;
+ return -1;
+ }
+ break;
+ case MNL_TYPE_NESTED:
+
+ if (attr_len == 0)
+ break;
+
+ if (attr_len < MNL_ATTR_HDRLEN) {
+ errno = ERANGE;
+ return -1;
+ }
+ break;
+ default:
+
+ break;
+ }
+ if (exp_len && attr_len > exp_len) {
+ errno = ERANGE;
+ return -1;
+ }
+ return 0;
+}
+
+static const size_t mnl_attr_data_type_len[MNL_TYPE_MAX] = {
+ [MNL_TYPE_U8] = sizeof(uint8_t),
+ [MNL_TYPE_U16] = sizeof(uint16_t),
+ [MNL_TYPE_U32] = sizeof(uint32_t),
+ [MNL_TYPE_U64] = sizeof(uint64_t),
+ [MNL_TYPE_MSECS] = sizeof(uint64_t),
+};
+
+static int mnl_attr_validate(const struct nlattr *attr, enum mnl_attr_data_type type)
+{
+ int exp_len;
+
+ if (type >= MNL_TYPE_MAX) {
+ errno = EINVAL;
+ return -1;
+ }
+ exp_len = mnl_attr_data_type_len[type];
+ return __mnl_attr_validate(attr, type, exp_len);
+}
+
+static int mnl_attr_parse(const struct nlmsghdr *nlh, unsigned int offset,
+ mnl_attr_cb_t cb, void *data)
+{
+ int ret = MNL_CB_OK;
+ const struct nlattr *attr;
+
+ mnl_attr_for_each(attr, nlh, offset)
+ if ((ret = cb(attr, data)) <= MNL_CB_STOP)
+ return ret;
+ return ret;
+}
+
+static int mnl_attr_parse_nested(const struct nlattr *nested, mnl_attr_cb_t cb,
+ void *data)
+{
+ int ret = MNL_CB_OK;
+ const struct nlattr *attr;
+
+ mnl_attr_for_each_nested(attr, nested)
+ if ((ret = cb(attr, data)) <= MNL_CB_STOP)
+ return ret;
+ return ret;
+}
+
+static uint8_t mnl_attr_get_u8(const struct nlattr *attr)
+{
+ return *((uint8_t *)mnl_attr_get_payload(attr));
+}
+
+static uint16_t mnl_attr_get_u16(const struct nlattr *attr)
+{
+ return *((uint16_t *)mnl_attr_get_payload(attr));
+}
+
+static uint32_t mnl_attr_get_u32(const struct nlattr *attr)
+{
+ return *((uint32_t *)mnl_attr_get_payload(attr));
+}
+
+static uint64_t mnl_attr_get_u64(const struct nlattr *attr)
+{
+ uint64_t tmp;
+ memcpy(&tmp, mnl_attr_get_payload(attr), sizeof(tmp));
+ return tmp;
+}
+
+static const char *mnl_attr_get_str(const struct nlattr *attr)
+{
+ return mnl_attr_get_payload(attr);
+}
+
+static void mnl_attr_put(struct nlmsghdr *nlh, uint16_t type, size_t len,
+ const void *data)
+{
+ struct nlattr *attr = mnl_nlmsg_get_payload_tail(nlh);
+ uint16_t payload_len = MNL_ALIGN(sizeof(struct nlattr)) + len;
+ int pad;
+
+ attr->nla_type = type;
+ attr->nla_len = payload_len;
+ memcpy(mnl_attr_get_payload(attr), data, len);
+ nlh->nlmsg_len += MNL_ALIGN(payload_len);
+ pad = MNL_ALIGN(len) - len;
+ if (pad > 0)
+ memset(mnl_attr_get_payload(attr) + len, 0, pad);
+}
+
+static void mnl_attr_put_u16(struct nlmsghdr *nlh, uint16_t type, uint16_t data)
+{
+ mnl_attr_put(nlh, type, sizeof(uint16_t), &data);
+}
+
+static void mnl_attr_put_u32(struct nlmsghdr *nlh, uint16_t type, uint32_t data)
+{
+ mnl_attr_put(nlh, type, sizeof(uint32_t), &data);
+}
+
+static void mnl_attr_put_strz(struct nlmsghdr *nlh, uint16_t type, const char *data)
+{
+ mnl_attr_put(nlh, type, strlen(data)+1, data);
+}
+
+static struct nlattr *mnl_attr_nest_start(struct nlmsghdr *nlh, uint16_t type)
+{
+ struct nlattr *start = mnl_nlmsg_get_payload_tail(nlh);
+
+ start->nla_type = NLA_F_NESTED | type;
+ nlh->nlmsg_len += MNL_ALIGN(sizeof(struct nlattr));
+ return start;
+}
+
+static bool mnl_attr_put_check(struct nlmsghdr *nlh, size_t buflen,
+ uint16_t type, size_t len, const void *data)
+{
+ if (nlh->nlmsg_len + MNL_ATTR_HDRLEN + MNL_ALIGN(len) > buflen)
+ return false;
+ mnl_attr_put(nlh, type, len, data);
+ return true;
+}
+
+static bool mnl_attr_put_u8_check(struct nlmsghdr *nlh, size_t buflen,
+ uint16_t type, uint8_t data)
+{
+ return mnl_attr_put_check(nlh, buflen, type, sizeof(uint8_t), &data);
+}
+
+static bool mnl_attr_put_u16_check(struct nlmsghdr *nlh, size_t buflen,
+ uint16_t type, uint16_t data)
+{
+ return mnl_attr_put_check(nlh, buflen, type, sizeof(uint16_t), &data);
+}
+
+static bool mnl_attr_put_u32_check(struct nlmsghdr *nlh, size_t buflen,
+ uint16_t type, uint32_t data)
+{
+ return mnl_attr_put_check(nlh, buflen, type, sizeof(uint32_t), &data);
+}
+
+static struct nlattr *mnl_attr_nest_start_check(struct nlmsghdr *nlh, size_t buflen,
+ uint16_t type)
+{
+ if (nlh->nlmsg_len + MNL_ATTR_HDRLEN > buflen)
+ return NULL;
+ return mnl_attr_nest_start(nlh, type);
+}
+
+static void mnl_attr_nest_end(struct nlmsghdr *nlh, struct nlattr *start)
+{
+ start->nla_len = mnl_nlmsg_get_payload_tail(nlh) - (void *)start;
+}
+
+static void mnl_attr_nest_cancel(struct nlmsghdr *nlh, struct nlattr *start)
+{
+ nlh->nlmsg_len -= mnl_nlmsg_get_payload_tail(nlh) - (void *)start;
+}
+
+static int mnl_cb_noop(__attribute__((unused)) const struct nlmsghdr *nlh, __attribute__((unused)) void *data)
+{
+ return MNL_CB_OK;
+}
+
+static int mnl_cb_error(const struct nlmsghdr *nlh, __attribute__((unused)) void *data)
+{
+ const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
+
+ if (nlh->nlmsg_len < mnl_nlmsg_size(sizeof(struct nlmsgerr))) {
+ errno = EBADMSG;
+ return MNL_CB_ERROR;
+ }
+
+ if (err->error < 0)
+ errno = -err->error;
+ else
+ errno = err->error;
+
+ return err->error == 0 ? MNL_CB_STOP : MNL_CB_ERROR;
+}
+
+static int mnl_cb_stop(__attribute__((unused)) const struct nlmsghdr *nlh, __attribute__((unused)) void *data)
+{
+ return MNL_CB_STOP;
+}
+
+static const mnl_cb_t default_cb_array[NLMSG_MIN_TYPE] = {
+ [NLMSG_NOOP] = mnl_cb_noop,
+ [NLMSG_ERROR] = mnl_cb_error,
+ [NLMSG_DONE] = mnl_cb_stop,
+ [NLMSG_OVERRUN] = mnl_cb_noop,
+};
+
+static int __mnl_cb_run(const void *buf, size_t numbytes,
+ unsigned int seq, unsigned int portid,
+ mnl_cb_t cb_data, void *data,
+ const mnl_cb_t *cb_ctl_array,
+ unsigned int cb_ctl_array_len)
+{
+ int ret = MNL_CB_OK, len = numbytes;
+ const struct nlmsghdr *nlh = buf;
+
+ while (mnl_nlmsg_ok(nlh, len)) {
+
+ if (!mnl_nlmsg_portid_ok(nlh, portid)) {
+ errno = ESRCH;
+ return -1;
+ }
+
+ if (!mnl_nlmsg_seq_ok(nlh, seq)) {
+ errno = EPROTO;
+ return -1;
+ }
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP_INTR) {
+ errno = EINTR;
+ return -1;
+ }
+
+ if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
+ if (cb_data){
+ ret = cb_data(nlh, data);
+ if (ret <= MNL_CB_STOP)
+ goto out;
+ }
+ } else if (nlh->nlmsg_type < cb_ctl_array_len) {
+ if (cb_ctl_array && cb_ctl_array[nlh->nlmsg_type]) {
+ ret = cb_ctl_array[nlh->nlmsg_type](nlh, data);
+ if (ret <= MNL_CB_STOP)
+ goto out;
+ }
+ } else if (default_cb_array[nlh->nlmsg_type]) {
+ ret = default_cb_array[nlh->nlmsg_type](nlh, data);
+ if (ret <= MNL_CB_STOP)
+ goto out;
+ }
+ nlh = mnl_nlmsg_next(nlh, &len);
+ }
+out:
+ return ret;
+}
+
+static int mnl_cb_run2(const void *buf, size_t numbytes, unsigned int seq,
+ unsigned int portid, mnl_cb_t cb_data, void *data,
+ const mnl_cb_t *cb_ctl_array, unsigned int cb_ctl_array_len)
+{
+ return __mnl_cb_run(buf, numbytes, seq, portid, cb_data, data,
+ cb_ctl_array, cb_ctl_array_len);
+}
+
+static int mnl_cb_run(const void *buf, size_t numbytes, unsigned int seq,
+ unsigned int portid, mnl_cb_t cb_data, void *data)
+{
+ return __mnl_cb_run(buf, numbytes, seq, portid, cb_data, data, NULL, 0);
+}
+
+struct mnl_socket {
+ int fd;
+ struct sockaddr_nl addr;
+};
+
+static unsigned int mnl_socket_get_portid(const struct mnl_socket *nl)
+{
+ return nl->addr.nl_pid;
+}
+
+static struct mnl_socket *__mnl_socket_open(int bus, int flags)
+{
+ struct mnl_socket *nl;
+
+ nl = calloc(1, sizeof(struct mnl_socket));
+ if (nl == NULL)
+ return NULL;
+
+ nl->fd = socket(AF_NETLINK, SOCK_RAW | flags, bus);
+ if (nl->fd == -1) {
+ free(nl);
+ return NULL;
+ }
+
+ return nl;
+}
+
+static struct mnl_socket *mnl_socket_open(int bus)
+{
+ return __mnl_socket_open(bus, 0);
+}
+
+static int mnl_socket_bind(struct mnl_socket *nl, unsigned int groups, pid_t pid)
+{
+ int ret;
+ socklen_t addr_len;
+
+ nl->addr.nl_family = AF_NETLINK;
+ nl->addr.nl_groups = groups;
+ nl->addr.nl_pid = pid;
+
+ ret = bind(nl->fd, (struct sockaddr *) &nl->addr, sizeof (nl->addr));
+ if (ret < 0)
+ return ret;
+
+ addr_len = sizeof(nl->addr);
+ ret = getsockname(nl->fd, (struct sockaddr *) &nl->addr, &addr_len);
+ if (ret < 0)
+ return ret;
+
+ if (addr_len != sizeof(nl->addr)) {
+ errno = EINVAL;
+ return -1;
+ }
+ if (nl->addr.nl_family != AF_NETLINK) {
+ errno = EINVAL;
+ return -1;
+ }
+ return 0;
+}
+
+static ssize_t mnl_socket_sendto(const struct mnl_socket *nl, const void *buf,
+ size_t len)
+{
+ static const struct sockaddr_nl snl = {
+ .nl_family = AF_NETLINK
+ };
+ return sendto(nl->fd, buf, len, 0,
+ (struct sockaddr *) &snl, sizeof(snl));
+}
+
+static ssize_t mnl_socket_recvfrom(const struct mnl_socket *nl, void *buf,
+ size_t bufsiz)
+{
+ ssize_t ret;
+ struct sockaddr_nl addr;
+ struct iovec iov = {
+ .iov_base = buf,
+ .iov_len = bufsiz,
+ };
+ struct msghdr msg = {
+ .msg_name = &addr,
+ .msg_namelen = sizeof(struct sockaddr_nl),
+ .msg_iov = &iov,
+ .msg_iovlen = 1,
+ .msg_control = NULL,
+ .msg_controllen = 0,
+ .msg_flags = 0,
+ };
+ ret = recvmsg(nl->fd, &msg, 0);
+ if (ret == -1)
+ return ret;
+
+ if (msg.msg_flags & MSG_TRUNC) {
+ errno = ENOSPC;
+ return -1;
+ }
+ if (msg.msg_namelen != sizeof(struct sockaddr_nl)) {
+ errno = EINVAL;
+ return -1;
+ }
+ return ret;
+}
+
+static int mnl_socket_close(struct mnl_socket *nl)
+{
+ int ret = close(nl->fd);
+ free(nl);
+ return ret;
+}
+
+/* This is a wrapper for generic netlink, originally from Jiri Pirko <jiri@mellanox.com>: */
+
+struct mnlg_socket {
+ struct mnl_socket *nl;
+ char *buf;
+ uint16_t id;
+ uint8_t version;
+ unsigned int seq;
+ unsigned int portid;
+};
+
+static struct nlmsghdr *__mnlg_msg_prepare(struct mnlg_socket *nlg, uint8_t cmd,
+ uint16_t flags, uint16_t id,
+ uint8_t version)
+{
+ struct nlmsghdr *nlh;
+ struct genlmsghdr *genl;
+
+ nlh = mnl_nlmsg_put_header(nlg->buf);
+ nlh->nlmsg_type = id;
+ nlh->nlmsg_flags = flags;
+ nlg->seq = time(NULL);
+ nlh->nlmsg_seq = nlg->seq;
+
+ genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));
+ genl->cmd = cmd;
+ genl->version = version;
+
+ return nlh;
+}
+
+static struct nlmsghdr *mnlg_msg_prepare(struct mnlg_socket *nlg, uint8_t cmd,
+ uint16_t flags)
+{
+ return __mnlg_msg_prepare(nlg, cmd, flags, nlg->id, nlg->version);
+}
+
+static int mnlg_socket_send(struct mnlg_socket *nlg, const struct nlmsghdr *nlh)
+{
+ return mnl_socket_sendto(nlg->nl, nlh, nlh->nlmsg_len);
+}
+
+static int mnlg_cb_noop(const struct nlmsghdr *nlh, void *data)
+{
+ (void)nlh;
+ (void)data;
+ return MNL_CB_OK;
+}
+
+static int mnlg_cb_error(const struct nlmsghdr *nlh, void *data)
+{
+ const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
+ (void)data;
+
+ if (nlh->nlmsg_len < mnl_nlmsg_size(sizeof(struct nlmsgerr))) {
+ errno = EBADMSG;
+ return MNL_CB_ERROR;
+ }
+ /* Netlink subsystems returns the errno value with different signess */
+ if (err->error < 0)
+ errno = -err->error;
+ else
+ errno = err->error;
+
+ return err->error == 0 ? MNL_CB_STOP : MNL_CB_ERROR;
+}
+
+static int mnlg_cb_stop(const struct nlmsghdr *nlh, void *data)
+{
+ (void)data;
+ if (nlh->nlmsg_flags & NLM_F_MULTI && nlh->nlmsg_len == mnl_nlmsg_size(sizeof(int))) {
+ int error = *(int *)mnl_nlmsg_get_payload(nlh);
+ /* Netlink subsystems returns the errno value with different signess */
+ if (error < 0)
+ errno = -error;
+ else
+ errno = error;
+
+ return error == 0 ? MNL_CB_STOP : MNL_CB_ERROR;
+ }
+ return MNL_CB_STOP;
+}
+
+static const mnl_cb_t mnlg_cb_array[] = {
+ [NLMSG_NOOP] = mnlg_cb_noop,
+ [NLMSG_ERROR] = mnlg_cb_error,
+ [NLMSG_DONE] = mnlg_cb_stop,
+ [NLMSG_OVERRUN] = mnlg_cb_noop,
+};
+
+static int mnlg_socket_recv_run(struct mnlg_socket *nlg, mnl_cb_t data_cb, void *data)
+{
+ int err;
+
+ do {
+ err = mnl_socket_recvfrom(nlg->nl, nlg->buf,
+ MNL_SOCKET_BUFFER_SIZE);
+ if (err <= 0)
+ break;
+ err = mnl_cb_run2(nlg->buf, err, nlg->seq, nlg->portid,
+ data_cb, data, mnlg_cb_array, MNL_ARRAY_SIZE(mnlg_cb_array));
+ } while (err > 0);
+
+ return err;
+}
+
+static int get_family_id_attr_cb(const struct nlattr *attr, void *data)
+{
+ const struct nlattr **tb = data;
+ int type = mnl_attr_get_type(attr);
+
+ 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)
+{
+ uint16_t *p_id = data;
+ struct nlattr *tb[CTRL_ATTR_MAX + 1] = { 0 };
+
+ mnl_attr_parse(nlh, sizeof(struct genlmsghdr), 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 struct mnlg_socket *mnlg_socket_open(const char *family_name, uint8_t version)
+{
+ struct mnlg_socket *nlg;
+ struct nlmsghdr *nlh;
+ int err;
+
+ nlg = malloc(sizeof(*nlg));
+ if (!nlg)
+ return NULL;
+
+ err = -ENOMEM;
+ nlg->buf = malloc(MNL_SOCKET_BUFFER_SIZE);
+ if (!nlg->buf)
+ goto err_buf_alloc;
+
+ nlg->nl = mnl_socket_open(NETLINK_GENERIC);
+ if (!nlg->nl) {
+ err = -errno;
+ goto err_mnl_socket_open;
+ }
+
+ if (mnl_socket_bind(nlg->nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+ err = -errno;
+ goto err_mnl_socket_bind;
+ }
+
+ nlg->portid = mnl_socket_get_portid(nlg->nl);
+
+ nlh = __mnlg_msg_prepare(nlg, CTRL_CMD_GETFAMILY,
+ NLM_F_REQUEST | NLM_F_ACK, GENL_ID_CTRL, 1);
+ mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, family_name);
+
+ if (mnlg_socket_send(nlg, nlh) < 0) {
+ err = -errno;
+ goto err_mnlg_socket_send;
+ }
+
+ errno = 0;
+ if (mnlg_socket_recv_run(nlg, get_family_id_cb, &nlg->id) < 0) {
+ errno = errno == ENOENT ? EPROTONOSUPPORT : errno;
+ err = errno ? -errno : -ENOSYS;
+ goto err_mnlg_socket_recv_run;
+ }
+
+ nlg->version = version;
+ errno = 0;
+ return nlg;
+
+err_mnlg_socket_recv_run:
+err_mnlg_socket_send:
+err_mnl_socket_bind:
+ mnl_socket_close(nlg->nl);
+err_mnl_socket_open:
+ free(nlg->buf);
+err_buf_alloc:
+ free(nlg);
+ errno = -err;
+ return NULL;
+}
+
+static void mnlg_socket_close(struct mnlg_socket *nlg)
+{
+ mnl_socket_close(nlg->nl);
+ free(nlg->buf);
+ free(nlg);
+}