build: move "shared/nm-platform" to "src/libnm-platform"

1 files changed, 1518 insertions, 0 deletions

diff --git a/src/libnm-platform/nm-netlink.c b/src/libnm-platform/nm-netlink.c
new file mode 100644
index 0000000000..7a6d7e045b
--- /dev/null
+++ b/src/libnm-platform/nm-netlink.c
@@ -0,0 +1,1518 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2018 Red Hat, Inc.
+ */
+
+#include "nm-glib-aux/nm-default-glib-i18n-lib.h"
+
+#include "nm-netlink.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+
+/*****************************************************************************/
+
+#ifndef SOL_NETLINK
+    #define SOL_NETLINK 270
+#endif
+
+/*****************************************************************************/
+
+#define NL_SOCK_PASSCRED     (1 << 1)
+#define NL_MSG_PEEK          (1 << 3)
+#define NL_MSG_PEEK_EXPLICIT (1 << 4)
+#define NL_NO_AUTO_ACK       (1 << 5)
+
+#ifndef NETLINK_EXT_ACK
+    #define NETLINK_EXT_ACK 11
+#endif
+
+struct nl_msg {
+    int                nm_protocol;
+    struct sockaddr_nl nm_src;
+    struct sockaddr_nl nm_dst;
+    struct ucred       nm_creds;
+    struct nlmsghdr *  nm_nlh;
+    size_t             nm_size;
+    bool               nm_creds_has : 1;
+};
+
+struct nl_sock {
+    struct sockaddr_nl s_local;
+    struct sockaddr_nl s_peer;
+    int                s_fd;
+    int                s_proto;
+    unsigned int       s_seq_next;
+    unsigned int       s_seq_expect;
+    int                s_flags;
+    size_t             s_bufsize;
+};
+
+/*****************************************************************************/
+
+NM_UTILS_ENUM2STR_DEFINE(nl_nlmsgtype2str,
+                         int,
+                         NM_UTILS_ENUM2STR(NLMSG_NOOP, "NOOP"),
+                         NM_UTILS_ENUM2STR(NLMSG_ERROR, "ERROR"),
+                         NM_UTILS_ENUM2STR(NLMSG_DONE, "DONE"),
+                         NM_UTILS_ENUM2STR(NLMSG_OVERRUN, "OVERRUN"), );
+
+NM_UTILS_FLAGS2STR_DEFINE(nl_nlmsg_flags2str,
+                          int,
+                          NM_UTILS_FLAGS2STR(NLM_F_REQUEST, "REQUEST"),
+                          NM_UTILS_FLAGS2STR(NLM_F_MULTI, "MULTI"),
+                          NM_UTILS_FLAGS2STR(NLM_F_ACK, "ACK"),
+                          NM_UTILS_FLAGS2STR(NLM_F_ECHO, "ECHO"),
+                          NM_UTILS_FLAGS2STR(NLM_F_ROOT, "ROOT"),
+                          NM_UTILS_FLAGS2STR(NLM_F_MATCH, "MATCH"),
+                          NM_UTILS_FLAGS2STR(NLM_F_ATOMIC, "ATOMIC"),
+                          NM_UTILS_FLAGS2STR(NLM_F_REPLACE, "REPLACE"),
+                          NM_UTILS_FLAGS2STR(NLM_F_EXCL, "EXCL"),
+                          NM_UTILS_FLAGS2STR(NLM_F_CREATE, "CREATE"),
+                          NM_UTILS_FLAGS2STR(NLM_F_APPEND, "APPEND"), );
+
+/*****************************************************************************/
+
+const char *
+nl_nlmsghdr_to_str(const struct nlmsghdr *hdr, char *buf, gsize len)
+{
+    const char *b;
+    const char *s;
+    guint       flags, flags_before;
+    const char *prefix;
+
+    if (!nm_utils_to_string_buffer_init_null(hdr, &buf, &len))
+        return buf;
+
+    b = buf;
+
+    switch (hdr->nlmsg_type) {
+    case RTM_GETLINK:
+        s = "RTM_GETLINK";
+        break;
+    case RTM_NEWLINK:
+        s = "RTM_NEWLINK";
+        break;
+    case RTM_DELLINK:
+        s = "RTM_DELLINK";
+        break;
+    case RTM_SETLINK:
+        s = "RTM_SETLINK";
+        break;
+    case RTM_GETADDR:
+        s = "RTM_GETADDR";
+        break;
+    case RTM_NEWADDR:
+        s = "RTM_NEWADDR";
+        break;
+    case RTM_DELADDR:
+        s = "RTM_DELADDR";
+        break;
+    case RTM_GETROUTE:
+        s = "RTM_GETROUTE";
+        break;
+    case RTM_NEWROUTE:
+        s = "RTM_NEWROUTE";
+        break;
+    case RTM_DELROUTE:
+        s = "RTM_DELROUTE";
+        break;
+    case RTM_GETRULE:
+        s = "RTM_GETRULE";
+        break;
+    case RTM_NEWRULE:
+        s = "RTM_NEWRULE";
+        break;
+    case RTM_DELRULE:
+        s = "RTM_DELRULE";
+        break;
+    case RTM_GETQDISC:
+        s = "RTM_GETQDISC";
+        break;
+    case RTM_NEWQDISC:
+        s = "RTM_NEWQDISC";
+        break;
+    case RTM_DELQDISC:
+        s = "RTM_DELQDISC";
+        break;
+    case RTM_GETTFILTER:
+        s = "RTM_GETTFILTER";
+        break;
+    case RTM_NEWTFILTER:
+        s = "RTM_NEWTFILTER";
+        break;
+    case RTM_DELTFILTER:
+        s = "RTM_DELTFILTER";
+        break;
+    case NLMSG_NOOP:
+        s = "NLMSG_NOOP";
+        break;
+    case NLMSG_ERROR:
+        s = "NLMSG_ERROR";
+        break;
+    case NLMSG_DONE:
+        s = "NLMSG_DONE";
+        break;
+    case NLMSG_OVERRUN:
+        s = "NLMSG_OVERRUN";
+        break;
+    default:
+        s = NULL;
+        break;
+    }
+
+    if (s)
+        nm_utils_strbuf_append_str(&buf, &len, s);
+    else
+        nm_utils_strbuf_append(&buf, &len, "(%u)", (unsigned) hdr->nlmsg_type);
+
+    flags = hdr->nlmsg_flags;
+
+    if (!flags) {
+        nm_utils_strbuf_append_str(&buf, &len, ", flags 0");
+        goto flags_done;
+    }
+
+#define _F(f, n)                                                   \
+    G_STMT_START                                                   \
+    {                                                              \
+        if (NM_FLAGS_ALL(flags, f)) {                              \
+            flags &= ~(f);                                         \
+            nm_utils_strbuf_append(&buf, &len, "%s%s", prefix, n); \
+            if (!flags)                                            \
+                goto flags_done;                                   \
+            prefix = ",";                                          \
+        }                                                          \
+    }                                                              \
+    G_STMT_END
+
+    prefix       = ", flags ";
+    flags_before = flags;
+    _F(NLM_F_REQUEST, "request");
+    _F(NLM_F_MULTI, "multi");
+    _F(NLM_F_ACK, "ack");
+    _F(NLM_F_ECHO, "echo");
+    _F(NLM_F_DUMP_INTR, "dump_intr");
+    _F(0x20 /*NLM_F_DUMP_FILTERED*/, "dump_filtered");
+
+    if (flags_before != flags)
+        prefix = ";";
+
+    switch (hdr->nlmsg_type) {
+    case RTM_NEWLINK:
+    case RTM_NEWADDR:
+    case RTM_NEWROUTE:
+    case RTM_NEWQDISC:
+    case RTM_NEWTFILTER:
+        _F(NLM_F_REPLACE, "replace");
+        _F(NLM_F_EXCL, "excl");
+        _F(NLM_F_CREATE, "create");
+        _F(NLM_F_APPEND, "append");
+        break;
+    case RTM_GETLINK:
+    case RTM_GETADDR:
+    case RTM_GETROUTE:
+    case RTM_DELQDISC:
+    case RTM_DELTFILTER:
+        _F(NLM_F_DUMP, "dump");
+        _F(NLM_F_ROOT, "root");
+        _F(NLM_F_MATCH, "match");
+        _F(NLM_F_ATOMIC, "atomic");
+        break;
+    }
+
+#undef _F
+
+    if (flags_before != flags)
+        prefix = ";";
+    nm_utils_strbuf_append(&buf, &len, "%s0x%04x", prefix, flags);
+
+flags_done:
+
+    nm_utils_strbuf_append(&buf, &len, ", seq %u", (unsigned) hdr->nlmsg_seq);
+
+    return b;
+}
+
+/*****************************************************************************/
+
+struct nlmsghdr *
+nlmsg_hdr(struct nl_msg *n)
+{
+    return n->nm_nlh;
+}
+
+void *
+nlmsg_reserve(struct nl_msg *n, size_t len, int pad)
+{
+    char * buf       = (char *) n->nm_nlh;
+    size_t nlmsg_len = n->nm_nlh->nlmsg_len;
+    size_t tlen;
+
+    nm_assert(pad >= 0);
+
+    if (len > n->nm_size)
+        return NULL;
+
+    tlen = pad ? ((len + (pad - 1)) & ~(pad - 1)) : len;
+
+    if ((tlen + nlmsg_len) > n->nm_size)
+        return NULL;
+
+    buf += nlmsg_len;
+    n->nm_nlh->nlmsg_len += tlen;
+
+    if (tlen > len)
+        memset(buf + len, 0, tlen - len);
+
+    return buf;
+}
+
+/*****************************************************************************/
+
+struct nlattr *
+nla_reserve(struct nl_msg *msg, int attrtype, int attrlen)
+{
+    struct nlattr *nla;
+    int            tlen;
+
+    if (attrlen < 0)
+        return NULL;
+
+    tlen = NLMSG_ALIGN(msg->nm_nlh->nlmsg_len) + nla_total_size(attrlen);
+
+    if (tlen > msg->nm_size)
+        return NULL;
+
+    nla           = (struct nlattr *) nlmsg_tail(msg->nm_nlh);
+    nla->nla_type = attrtype;
+    nla->nla_len  = nla_attr_size(attrlen);
+
+    if (attrlen)
+        memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
+    msg->nm_nlh->nlmsg_len = tlen;
+
+    return nla;
+}
+
+/*****************************************************************************/
+
+struct nl_msg *
+nlmsg_alloc_size(size_t len)
+{
+    struct nl_msg *nm;
+
+    if (len < sizeof(struct nlmsghdr))
+        len = sizeof(struct nlmsghdr);
+
+    nm  = g_slice_new(struct nl_msg);
+    *nm = (struct nl_msg){
+        .nm_protocol = -1,
+        .nm_size     = len,
+        .nm_nlh      = g_malloc0(len),
+    };
+    nm->nm_nlh->nlmsg_len = nlmsg_total_size(0);
+    return nm;
+}
+
+/**
+ * Allocate a new netlink message with the default maximum payload size.
+ *
+ * Allocates a new netlink message without any further payload. The
+ * maximum payload size defaults to PAGESIZE or as otherwise specified
+ * with nlmsg_set_default_size().
+ *
+ * @return Newly allocated netlink message or NULL.
+ */
+struct nl_msg *
+nlmsg_alloc(void)
+{
+    return nlmsg_alloc_size(nm_utils_getpagesize());
+}
+
+struct nl_msg *
+nlmsg_alloc_convert(struct nlmsghdr *hdr)
+{
+    struct nl_msg *nm;
+
+    nm = nlmsg_alloc_size(NLMSG_ALIGN(hdr->nlmsg_len));
+    memcpy(nm->nm_nlh, hdr, hdr->nlmsg_len);
+    return nm;
+}
+
+struct nl_msg *
+nlmsg_alloc_simple(int nlmsgtype, int flags)
+{
+    struct nl_msg *nm;
+    struct nlmsghdr *new;
+
+    nm               = nlmsg_alloc();
+    new              = nm->nm_nlh;
+    new->nlmsg_type  = nlmsgtype;
+    new->nlmsg_flags = flags;
+    return nm;
+}
+
+void
+nlmsg_free(struct nl_msg *msg)
+{
+    if (!msg)
+        return;
+
+    g_free(msg->nm_nlh);
+    g_slice_free(struct nl_msg, msg);
+}
+
+/*****************************************************************************/
+
+int
+nlmsg_append(struct nl_msg *n, const void *data, size_t len, int pad)
+{
+    void *tmp;
+
+    nm_assert(n);
+    nm_assert(data);
+    nm_assert(len > 0);
+    nm_assert(pad >= 0);
+
+    tmp = nlmsg_reserve(n, len, pad);
+    if (tmp == NULL)
+        return -ENOMEM;
+
+    memcpy(tmp, data, len);
+    return 0;
+}
+
+/*****************************************************************************/
+
+int
+nlmsg_parse(struct nlmsghdr *        nlh,
+            int                      hdrlen,
+            struct nlattr *          tb[],
+            int                      maxtype,
+            const struct nla_policy *policy)
+{
+    if (!nlmsg_valid_hdr(nlh, hdrlen))
+        return -NME_NL_MSG_TOOSHORT;
+
+    return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), policy);
+}
+
+struct nlmsghdr *
+nlmsg_put(struct nl_msg *n, uint32_t pid, uint32_t seq, int type, int payload, int flags)
+{
+    struct nlmsghdr *nlh;
+
+    if (n->nm_nlh->nlmsg_len < NLMSG_HDRLEN)
+        g_return_val_if_reached(NULL);
+
+    nlh              = (struct nlmsghdr *) n->nm_nlh;
+    nlh->nlmsg_type  = type;
+    nlh->nlmsg_flags = flags;
+    nlh->nlmsg_pid   = pid;
+    nlh->nlmsg_seq   = seq;
+
+    if (payload > 0 && nlmsg_reserve(n, payload, NLMSG_ALIGNTO) == NULL)
+        return NULL;
+
+    return nlh;
+}
+
+size_t
+nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
+{
+    const char *src;
+    size_t      srclen;
+    size_t      len;
+
+    /* - Always writes @dstsize bytes to @dst
+     * - Copies the first non-NUL characters to @dst.
+     *   Any characters after the first NUL bytes in @nla are ignored.
+     * - If the string @nla is longer than @dstsize, the string
+     *   gets truncated. @dst will always be NUL terminated. */
+
+    if (G_UNLIKELY(dstsize <= 1)) {
+        if (dstsize == 1)
+            dst[0] = '\0';
+        if (nla && (srclen = nla_len(nla)) > 0)
+            return strnlen(nla_data(nla), srclen);
+        return 0;
+    }
+
+    nm_assert(dst);
+
+    if (nla) {
+        srclen = nla_len(nla);
+        if (srclen > 0) {
+            src    = nla_data(nla);
+            srclen = strnlen(src, srclen);
+            if (srclen > 0) {
+                len = NM_MIN(dstsize - 1, srclen);
+                memcpy(dst, src, len);
+                memset(&dst[len], 0, dstsize - len);
+                return srclen;
+            }
+        }
+    }
+
+    memset(dst, 0, dstsize);
+    return 0;
+}
+
+size_t
+nla_memcpy(void *dst, const struct nlattr *nla, size_t dstsize)
+{
+    size_t len;
+    int    srclen;
+
+    if (!nla)
+        return 0;
+
+    srclen = nla_len(nla);
+
+    if (srclen <= 0) {
+        nm_assert(srclen == 0);
+        return 0;
+    }
+
+    len = NM_MIN((size_t) srclen, dstsize);
+    if (len > 0) {
+        /* there is a crucial difference between nla_strlcpy() and nla_memcpy().
+         * The former always write @dstsize bytes (akin to strncpy()), here, we only
+         * write the bytes that we actually have (leaving the remainder undefined). */
+        memcpy(dst, nla_data(nla), len);
+    }
+
+    return srclen;
+}
+
+int
+nla_put(struct nl_msg *msg, int attrtype, int datalen, const void *data)
+{
+    struct nlattr *nla;
+
+    nla = nla_reserve(msg, attrtype, datalen);
+    if (!nla) {
+        if (datalen < 0)
+            g_return_val_if_reached(-NME_BUG);
+
+        return -ENOMEM;
+    }
+
+    if (datalen > 0)
+        memcpy(nla_data(nla), data, datalen);
+
+    return 0;
+}
+
+struct nlattr *
+nla_find(const struct nlattr *head, int len, int attrtype)
+{
+    const struct nlattr *nla;
+    int                  rem;
+
+    nla_for_each_attr (nla, head, len, rem) {
+        if (nla_type(nla) == attrtype)
+            return (struct nlattr *) nla;
+    }
+
+    return NULL;
+}
+
+void
+nla_nest_cancel(struct nl_msg *msg, const struct nlattr *attr)
+{
+    ssize_t len;
+
+    len = (char *) nlmsg_tail(msg->nm_nlh) - (char *) attr;
+    if (len < 0)
+        g_return_if_reached();
+    else if (len > 0) {
+        msg->nm_nlh->nlmsg_len -= len;
+        memset(nlmsg_tail(msg->nm_nlh), 0, len);
+    }
+}
+
+struct nlattr *
+nla_nest_start(struct nl_msg *msg, int attrtype)
+{
+    struct nlattr *start = (struct nlattr *) nlmsg_tail(msg->nm_nlh);
+
+    if (nla_put(msg, NLA_F_NESTED | attrtype, 0, NULL) < 0)
+        return NULL;
+
+    return start;
+}
+
+static int
+_nest_end(struct nl_msg *msg, struct nlattr *start, int keep_empty)
+{
+    size_t pad, len;
+
+    len = (char *) nlmsg_tail(msg->nm_nlh) - (char *) start;
+
+    if (len > USHRT_MAX || (!keep_empty && len == NLA_HDRLEN)) {
+        /*
+         * Max nlattr size exceeded or empty nested attribute, trim the
+         * attribute header again
+         */
+        nla_nest_cancel(msg, start);
+
+        /* Return error only if nlattr size was exceeded */
+        return (len == NLA_HDRLEN) ? 0 : -NME_NL_ATTRSIZE;
+    }
+
+    start->nla_len = len;
+
+    pad = NLMSG_ALIGN(msg->nm_nlh->nlmsg_len) - msg->nm_nlh->nlmsg_len;
+    if (pad > 0) {
+        /*
+         * Data inside attribute does not end at a alignment boundary.
+         * Pad accordingly and account for the additional space in
+         * the message. nlmsg_reserve() may never fail in this situation,
+         * the allocate message buffer must be a multiple of NLMSG_ALIGNTO.
+         */
+        if (!nlmsg_reserve(msg, pad, 0))
+            g_return_val_if_reached(-NME_BUG);
+    }
+
+    return 0;
+}
+
+int
+nla_nest_end(struct nl_msg *msg, struct nlattr *start)
+{
+    return _nest_end(msg, start, 0);
+}
+
+static const uint16_t nla_attr_minlen[NLA_TYPE_MAX + 1] = {
+    [NLA_U8]     = sizeof(uint8_t),
+    [NLA_U16]    = sizeof(uint16_t),
+    [NLA_U32]    = sizeof(uint32_t),
+    [NLA_U64]    = sizeof(uint64_t),
+    [NLA_STRING] = 1,
+    [NLA_FLAG]   = 0,
+};
+
+static int
+validate_nla(const struct nlattr *nla, int maxtype, const struct nla_policy *policy)
+{
+    const struct nla_policy *pt;
+    unsigned int             minlen = 0;
+    int                      type   = nla_type(nla);
+
+    if (type < 0 || type > maxtype)
+        return 0;
+
+    pt = &policy[type];
+
+    if (pt->type > NLA_TYPE_MAX)
+        g_return_val_if_reached(-NME_BUG);
+
+    if (pt->minlen)
+        minlen = pt->minlen;
+    else if (pt->type != NLA_UNSPEC)
+        minlen = nla_attr_minlen[pt->type];
+
+    if (nla_len(nla) < minlen)
+        return -NME_UNSPEC;
+
+    if (pt->maxlen && nla_len(nla) > pt->maxlen)
+        return -NME_UNSPEC;
+
+    if (pt->type == NLA_STRING) {
+        const char *data;
+
+        nm_assert(minlen > 0);
+
+        data = nla_data(nla);
+        if (data[nla_len(nla) - 1] != '\0')
+            return -NME_UNSPEC;
+    }
+
+    return 0;
+}
+
+int
+nla_parse(struct nlattr *          tb[],
+          int                      maxtype,
+          struct nlattr *          head,
+          int                      len,
+          const struct nla_policy *policy)
+{
+    struct nlattr *nla;
+    int            rem, nmerr;
+
+    memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
+
+    nla_for_each_attr (nla, head, len, rem) {
+        int type = nla_type(nla);
+
+        if (type > maxtype)
+            continue;
+
+        if (policy) {
+            nmerr = validate_nla(nla, maxtype, policy);
+            if (nmerr < 0)
+                return nmerr;
+        }
+
+        tb[type] = nla;
+    }
+
+    return 0;
+}
+
+/*****************************************************************************/
+
+int
+nlmsg_get_proto(struct nl_msg *msg)
+{
+    return msg->nm_protocol;
+}
+
+void
+nlmsg_set_proto(struct nl_msg *msg, int protocol)
+{
+    msg->nm_protocol = protocol;
+}
+
+void
+nlmsg_set_src(struct nl_msg *msg, struct sockaddr_nl *addr)
+{
+    memcpy(&msg->nm_src, addr, sizeof(*addr));
+}
+
+struct ucred *
+nlmsg_get_creds(struct nl_msg *msg)
+{
+    if (msg->nm_creds_has)
+        return &msg->nm_creds;
+    return NULL;
+}
+
+void
+nlmsg_set_creds(struct nl_msg *msg, struct ucred *creds)
+{
+    if (creds) {
+        memcpy(&msg->nm_creds, creds, sizeof(*creds));
+        msg->nm_creds_has = TRUE;
+    } else
+        msg->nm_creds_has = FALSE;
+}
+
+/*****************************************************************************/
+
+void *
+genlmsg_put(struct nl_msg *msg,
+            uint32_t       port,
+            uint32_t       seq,
+            int            family,
+            int            hdrlen,
+            int            flags,
+            uint8_t        cmd,
+            uint8_t        version)
+{
+    struct nlmsghdr * nlh;
+    struct genlmsghdr hdr = {
+        .cmd     = cmd,
+        .version = version,
+    };
+
+    nlh = nlmsg_put(msg, port, seq, family, GENL_HDRLEN + hdrlen, flags);
+    if (nlh == NULL)
+        return NULL;
+
+    memcpy(nlmsg_data(nlh), &hdr, sizeof(hdr));
+
+    return (char *) nlmsg_data(nlh) + GENL_HDRLEN;
+}
+
+void *
+genlmsg_data(const struct genlmsghdr *gnlh)
+{
+    return ((unsigned char *) gnlh + GENL_HDRLEN);
+}
+
+void *
+genlmsg_user_hdr(const struct genlmsghdr *gnlh)
+{
+    return genlmsg_data(gnlh);
+}
+
+struct genlmsghdr *
+genlmsg_hdr(struct nlmsghdr *nlh)
+{
+    return nlmsg_data(nlh);
+}
+
+void *
+genlmsg_user_data(const struct genlmsghdr *gnlh, const int hdrlen)
+{
+    return (char *) genlmsg_user_hdr(gnlh) + NLMSG_ALIGN(hdrlen);
+}
+
+struct nlattr *
+genlmsg_attrdata(const struct genlmsghdr *gnlh, int hdrlen)
+{
+    return genlmsg_user_data(gnlh, hdrlen);
+}
+
+int
+genlmsg_len(const struct genlmsghdr *gnlh)
+{
+    const struct nlmsghdr *nlh;
+
+    nlh = (const struct nlmsghdr *) ((const unsigned char *) gnlh - NLMSG_HDRLEN);
+    return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
+}
+
+int
+genlmsg_attrlen(const struct genlmsghdr *gnlh, int hdrlen)
+{
+    return genlmsg_len(gnlh) - NLMSG_ALIGN(hdrlen);
+}
+
+int
+genlmsg_valid_hdr(struct nlmsghdr *nlh, int hdrlen)
+{
+    struct genlmsghdr *ghdr;
+
+    if (!nlmsg_valid_hdr(nlh, GENL_HDRLEN))
+        return 0;
+
+    ghdr = nlmsg_data(nlh);
+    if (genlmsg_len(ghdr) < NLMSG_ALIGN(hdrlen))
+        return 0;
+
+    return 1;
+}
+
+int
+genlmsg_parse(struct nlmsghdr *        nlh,
+              int                      hdrlen,
+              struct nlattr *          tb[],
+              int                      maxtype,
+              const struct nla_policy *policy)
+{
+    struct genlmsghdr *ghdr;
+
+    if (!genlmsg_valid_hdr(nlh, hdrlen))
+        return -NME_NL_MSG_TOOSHORT;
+
+    ghdr = nlmsg_data(nlh);
+    return nla_parse(tb,
+                     maxtype,
+                     genlmsg_attrdata(ghdr, hdrlen),
+                     genlmsg_attrlen(ghdr, hdrlen),
+                     policy);
+}
+
+static int
+_genl_parse_getfamily(struct nl_msg *msg, void *arg)
+{
+    static const struct nla_policy ctrl_policy[] = {
+        [CTRL_ATTR_FAMILY_ID]    = {.type = NLA_U16},
+        [CTRL_ATTR_FAMILY_NAME]  = {.type = NLA_STRING, .maxlen = GENL_NAMSIZ},
+        [CTRL_ATTR_VERSION]      = {.type = NLA_U32},
+        [CTRL_ATTR_HDRSIZE]      = {.type = NLA_U32},
+        [CTRL_ATTR_MAXATTR]      = {.type = NLA_U32},
+        [CTRL_ATTR_OPS]          = {.type = NLA_NESTED},
+        [CTRL_ATTR_MCAST_GROUPS] = {.type = NLA_NESTED},
+    };
+    struct nlattr *  tb[G_N_ELEMENTS(ctrl_policy)];
+    struct nlmsghdr *nlh           = nlmsg_hdr(msg);
+    gint32 *         response_data = arg;
+
+    if (genlmsg_parse_arr(nlh, 0, tb, ctrl_policy) < 0)
+        return NL_SKIP;
+
+    if (tb[CTRL_ATTR_FAMILY_ID])
+        *response_data = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]);
+
+    return NL_STOP;
+}
+
+int
+genl_ctrl_resolve(struct nl_sock *sk, const char *name)
+{
+    nm_auto_nlmsg struct nl_msg *msg = NULL;
+    int                          nmerr;
+    gint32                       response_data = -1;
+    const struct nl_cb           cb            = {
+        .valid_cb  = _genl_parse_getfamily,
+        .valid_arg = &response_data,
+    };
+
+    msg = nlmsg_alloc();
+
+    if (!genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, GENL_ID_CTRL, 0, 0, CTRL_CMD_GETFAMILY, 1))
+        return -ENOMEM;
+
+    nmerr = nla_put_string(msg, CTRL_ATTR_FAMILY_NAME, name);
+    if (nmerr < 0)
+        return nmerr;
+
+    nmerr = nl_send_auto(sk, msg);
+    if (nmerr < 0)
+        return nmerr;
+
+    nmerr = nl_recvmsgs(sk, &cb);
+    if (nmerr < 0)
+        return nmerr;
+
+    /* If search was successful, request may be ACKed after data */
+    nmerr = nl_wait_for_ack(sk, NULL);
+    if (nmerr < 0)
+        return nmerr;
+
+    if (response_data < 0)
+        return -NME_UNSPEC;
+
+    return response_data;
+}
+
+/*****************************************************************************/
+
+struct nl_sock *
+nl_socket_alloc(void)
+{
+    struct nl_sock *sk;
+
+    sk = g_slice_new0(struct nl_sock);
+
+    sk->s_fd              = -1;
+    sk->s_local.nl_family = AF_NETLINK;
+    sk->s_peer.nl_family  = AF_NETLINK;
+    sk->s_seq_expect = sk->s_seq_next = time(NULL);
+
+    return sk;
+}
+
+void
+nl_socket_free(struct nl_sock *sk)
+{
+    if (!sk)
+        return;
+
+    if (sk->s_fd >= 0)
+        nm_close(sk->s_fd);
+    g_slice_free(struct nl_sock, sk);
+}
+
+int
+nl_socket_get_fd(const struct nl_sock *sk)
+{
+    return sk->s_fd;
+}
+
+uint32_t
+nl_socket_get_local_port(const struct nl_sock *sk)
+{
+    return sk->s_local.nl_pid;
+}
+
+size_t
+nl_socket_get_msg_buf_size(struct nl_sock *sk)
+{
+    return sk->s_bufsize;
+}
+
+int
+nl_socket_set_passcred(struct nl_sock *sk, int state)
+{
+    int err;
+
+    if (sk->s_fd == -1)
+        return -NME_NL_BAD_SOCK;
+
+    err = setsockopt(sk->s_fd, SOL_SOCKET, SO_PASSCRED, &state, sizeof(state));
+    if (err < 0)
+        return -nm_errno_from_native(errno);
+
+    if (state)
+        sk->s_flags |= NL_SOCK_PASSCRED;
+    else
+        sk->s_flags &= ~NL_SOCK_PASSCRED;
+
+    return 0;
+}
+
+int
+nl_socket_set_msg_buf_size(struct nl_sock *sk, size_t bufsize)
+{
+    sk->s_bufsize = bufsize;
+
+    return 0;
+}
+
+struct sockaddr_nl *
+nlmsg_get_dst(struct nl_msg *msg)
+{
+    return &msg->nm_dst;
+}
+
+int
+nl_socket_set_nonblocking(const struct nl_sock *sk)
+{
+    if (sk->s_fd == -1)
+        return -NME_NL_BAD_SOCK;
+
+    if (fcntl(sk->s_fd, F_SETFL, O_NONBLOCK) < 0)
+        return -nm_errno_from_native(errno);
+
+    return 0;
+}
+
+int
+nl_socket_set_buffer_size(struct nl_sock *sk, int rxbuf, int txbuf)
+{
+    int err;
+
+    if (rxbuf <= 0)
+        rxbuf = 32768;
+
+    if (txbuf <= 0)
+        txbuf = 32768;
+
+    if (sk->s_fd == -1)
+        return -NME_NL_BAD_SOCK;
+
+    err = setsockopt(sk->s_fd, SOL_SOCKET, SO_SNDBUF, &txbuf, sizeof(txbuf));
+    if (err < 0) {
+        return -nm_errno_from_native(errno);
+    }
+
+    err = setsockopt(sk->s_fd, SOL_SOCKET, SO_RCVBUF, &rxbuf, sizeof(rxbuf));
+    if (err < 0) {
+        return -nm_errno_from_native(errno);
+    }
+
+    return 0;
+}
+
+int
+nl_socket_add_memberships(struct nl_sock *sk, int group, ...)
+{
+    int     err;
+    va_list ap;
+
+    if (sk->s_fd == -1)
+        return -NME_NL_BAD_SOCK;
+
+    va_start(ap, group);
+
+    while (group != 0) {
+        if (group < 0) {
+            va_end(ap);
+            g_return_val_if_reached(-NME_BUG);
+        }
+
+        err = setsockopt(sk->s_fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
+        if (err < 0) {
+            int errsv = errno;
+
+            va_end(ap);
+            return -nm_errno_from_native(errsv);
+        }
+
+        group = va_arg(ap, int);
+    }
+
+    va_end(ap);
+
+    return 0;
+}
+
+int
+nl_socket_set_ext_ack(struct nl_sock *sk, gboolean enable)
+{
+    int err, val;
+
+    if (sk->s_fd == -1)
+        return -NME_NL_BAD_SOCK;
+
+    val = !!enable;
+    err = setsockopt(sk->s_fd, SOL_NETLINK, NETLINK_EXT_ACK, &val, sizeof(val));
+    if (err < 0)
+        return -nm_errno_from_native(errno);
+
+    return 0;
+}
+
+void
+nl_socket_disable_msg_peek(struct nl_sock *sk)
+{
+    sk->s_flags |= NL_MSG_PEEK_EXPLICIT;
+    sk->s_flags &= ~NL_MSG_PEEK;
+}
+
+int
+nl_connect(struct nl_sock *sk, int protocol)
+{
+    int                err, nmerr;
+    socklen_t          addrlen;
+    struct sockaddr_nl local = {0};
+
+    if (sk->s_fd != -1)
+        return -NME_NL_BAD_SOCK;
+
+    sk->s_fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
+    if (sk->s_fd < 0) {
+        nmerr = -nm_errno_from_native(errno);
+        goto errout;
+    }
+
+    nmerr = nl_socket_set_buffer_size(sk, 0, 0);
+    if (nmerr < 0)
+        goto errout;
+
+    nm_assert(sk->s_local.nl_pid == 0);
+
+    err = bind(sk->s_fd, (struct sockaddr *) &sk->s_local, sizeof(sk->s_local));
+    if (err != 0) {
+        nmerr = -nm_errno_from_native(errno);
+        goto errout;
+    }
+
+    addrlen = sizeof(local);
+    err     = getsockname(sk->s_fd, (struct sockaddr *) &local, &addrlen);
+    if (err < 0) {
+        nmerr = -nm_errno_from_native(errno);
+        goto errout;
+    }
+
+    if (addrlen != sizeof(local)) {
+        nmerr = -NME_UNSPEC;
+        goto errout;
+    }
+
+    if (local.nl_family != AF_NETLINK) {
+        nmerr = -NME_UNSPEC;
+        goto errout;
+    }
+
+    sk->s_local = local;
+    sk->s_proto = protocol;
+
+    return 0;
+
+errout:
+    if (sk->s_fd != -1) {
+        close(sk->s_fd);
+        sk->s_fd = -1;
+    }
+    return nmerr;
+}
+
+/*****************************************************************************/
+
+static void
+_cb_init(struct nl_cb *dst, const struct nl_cb *src)
+{
+    nm_assert(dst);
+
+    if (src)
+        *dst = *src;
+    else
+        memset(dst, 0, sizeof(*dst));
+}
+
+static int
+ack_wait_handler(struct nl_msg *msg, void *arg)
+{
+    return NL_STOP;
+}
+
+int
+nl_wait_for_ack(struct nl_sock *sk, const struct nl_cb *cb)
+{
+    struct nl_cb cb2;
+
+    _cb_init(&cb2, cb);
+    cb2.ack_cb = ack_wait_handler;
+    return nl_recvmsgs(sk, &cb2);
+}
+
+#define NL_CB_CALL(cb, type, msg)                                \
+    do {                                                         \
+        const struct nl_cb *_cb = (cb);                          \
+                                                                 \
+        if (_cb && _cb->type##_cb) {                             \
+            /* the returned value here must be either a negative
+         * netlink error number, or one of NL_SKIP, NL_STOP, NL_OK. */ \
+            nmerr = _cb->type##_cb((msg), _cb->type##_arg);      \
+            switch (nmerr) {                                     \
+            case NL_OK:                                          \
+                nm_assert(nmerr == 0);                           \
+                break;                                           \
+            case NL_SKIP:                                        \
+                goto skip;                                       \
+            case NL_STOP:                                        \
+                goto stop;                                       \
+            default:                                             \
+                if (nmerr >= 0) {                                \
+                    nm_assert_not_reached();                     \
+                    nmerr = -NME_BUG;                            \
+                }                                                \
+                goto out;                                        \
+            }                                                    \
+        }                                                        \
+    } while (0)
+
+int
+nl_recvmsgs(struct nl_sock *sk, const struct nl_cb *cb)
+{
+    int                    n, nmerr = 0, multipart = 0, interrupted = 0, nrecv = 0;
+    gs_free unsigned char *buf = NULL;
+    struct nlmsghdr *      hdr;
+    struct sockaddr_nl     nla = {0};
+    struct ucred           creds;
+    gboolean               creds_has;
+
+continue_reading:
+    n = nl_recv(sk, &nla, &buf, &creds, &creds_has);
+    if (n <= 0)
+        return n;
+
+    hdr = (struct nlmsghdr *) buf;
+    while (nlmsg_ok(hdr, n)) {
+        nm_auto_nlmsg struct nl_msg *msg = NULL;
+
+        msg = nlmsg_alloc_convert(hdr);
+
+        nlmsg_set_proto(msg, sk->s_proto);
+        nlmsg_set_src(msg, &nla);
+        nlmsg_set_creds(msg, creds_has ? &creds : NULL);
+
+        nrecv++;
+
+        /* Only do sequence checking if auto-ack mode is enabled */
+        if (!(sk->s_flags & NL_NO_AUTO_ACK)) {
+            if (hdr->nlmsg_seq != sk->s_seq_expect) {
+                nmerr = -NME_NL_SEQ_MISMATCH;
+                goto out;
+            }
+        }
+
+        if (hdr->nlmsg_type == NLMSG_DONE || hdr->nlmsg_type == NLMSG_ERROR
+            || hdr->nlmsg_type == NLMSG_NOOP || hdr->nlmsg_type == NLMSG_OVERRUN) {
+            /* We can't check for !NLM_F_MULTI since some netlink
+             * users in the kernel are broken. */
+            sk->s_seq_expect++;
+        }
+
+        if (hdr->nlmsg_flags & NLM_F_MULTI)
+            multipart = 1;
+
+        if (hdr->nlmsg_flags & NLM_F_DUMP_INTR) {
+            /*
+             * We have to continue reading to clear
+             * all messages until a NLMSG_DONE is
+             * received and report the inconsistency.
+             */
+            interrupted = 1;
+        }
+
+        /* messages terminates a multipart message, this is
+         * usually the end of a message and therefore we slip
+         * out of the loop by default. the user may overrule
+         * this action by skipping this packet. */
+        if (hdr->nlmsg_type == NLMSG_DONE) {
+            multipart = 0;
+            NL_CB_CALL(cb, finish, msg);
+        }
+
+        /* Message to be ignored, the default action is to
+         * skip this message if no callback is specified. The
+         * user may overrule this action by returning
+         * NL_PROCEED. */
+        else if (hdr->nlmsg_type == NLMSG_NOOP)
+            goto skip;
+
+        /* Data got lost, report back to user. The default action is to
+         * quit parsing. The user may overrule this action by returning
+         * NL_SKIP or NL_PROCEED (dangerous) */
+        else if (hdr->nlmsg_type == NLMSG_OVERRUN) {
+            nmerr = -NME_NL_MSG_OVERFLOW;
+            goto out;
+        }
+
+        /* Message carries a nlmsgerr */
+        else if (hdr->nlmsg_type == NLMSG_ERROR) {
+            struct nlmsgerr *e = nlmsg_data(hdr);
+
+            if (hdr->nlmsg_len < nlmsg_size(sizeof(*e))) {
+                /* Truncated error message, the default action
+                 * is to stop parsing. The user may overrule
+                 * this action by returning NL_SKIP or
+                 * NL_PROCEED (dangerous) */
+                nmerr = -NME_NL_MSG_TRUNC;
+                goto out;
+            }
+            if (e->error) {
+                /* Error message reported back from kernel. */
+                if (cb && cb->err_cb) {
+                    /* the returned value here must be either a negative
+                     * netlink error number, or one of NL_SKIP, NL_STOP, NL_OK. */
+                    nmerr = cb->err_cb(&nla, e, cb->err_arg);
+                    if (nmerr < 0)
+                        goto out;
+                    else if (nmerr == NL_SKIP)
+                        goto skip;
+                    else if (nmerr == NL_STOP) {
+                        nmerr = -nm_errno_from_native(e->error);
+                        goto out;
+                    }
+                    nm_assert(nmerr == NL_OK);
+                } else {
+                    nmerr = -nm_errno_from_native(e->error);
+                    goto out;
+                }
+            } else
+                NL_CB_CALL(cb, ack, msg);
+        } else {
+            /* Valid message (not checking for MULTIPART bit to
+             * get along with broken kernels. NL_SKIP has no
+             * effect on this.  */
+            NL_CB_CALL(cb, valid, msg);
+        }
+skip:
+        nmerr = 0;
+        hdr   = nlmsg_next(hdr, &n);
+    }
+
+    if (multipart) {
+        /* Multipart message not yet complete, continue reading */
+        nm_clear_g_free(&buf);
+
+        nmerr = 0;
+        goto continue_reading;
+    }
+
+stop:
+    nmerr = 0;
+
+out:
+    if (interrupted)
+        nmerr = -NME_NL_DUMP_INTR;
+
+    nm_assert(nmerr <= 0);
+    return nmerr ?: nrecv;
+}
+
+int
+nl_sendmsg(struct nl_sock *sk, struct nl_msg *msg, struct msghdr *hdr)
+{
+    int ret;
+
+    if (sk->s_fd < 0)
+        return -NME_NL_BAD_SOCK;
+
+    nlmsg_set_src(msg, &sk->s_local);
+
+    ret = sendmsg(sk->s_fd, hdr, 0);
+    if (ret < 0)
+        return -nm_errno_from_native(errno);
+
+    return ret;
+}
+
+int
+nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg, struct iovec *iov, unsigned iovlen)
+{
+    struct sockaddr_nl *dst;
+    struct ucred *      creds;
+    struct msghdr       hdr = {
+        .msg_name    = (void *) &sk->s_peer,
+        .msg_namelen = sizeof(struct sockaddr_nl),
+        .msg_iov     = iov,
+        .msg_iovlen  = iovlen,
+    };
+    char buf[CMSG_SPACE(sizeof(struct ucred))];
+
+    /* Overwrite destination if specified in the message itself, defaults
+     * to the peer address of the socket.
+     */
+    dst = nlmsg_get_dst(msg);
+    if (dst->nl_family == AF_NETLINK)
+        hdr.msg_name = dst;
+
+    /* Add credentials if present. */
+    creds = nlmsg_get_creds(msg);
+    if (creds != NULL) {
+        struct cmsghdr *cmsg;
+
+        hdr.msg_control    = buf;
+        hdr.msg_controllen = sizeof(buf);
+
+        cmsg             = CMSG_FIRSTHDR(&hdr);
+        cmsg->cmsg_level = SOL_SOCKET;
+        cmsg->cmsg_type  = SCM_CREDENTIALS;
+        cmsg->cmsg_len   = CMSG_LEN(sizeof(struct ucred));
+        memcpy(CMSG_DATA(cmsg), creds, sizeof(struct ucred));
+    }
+
+    return nl_sendmsg(sk, msg, &hdr);
+}
+
+void
+nl_complete_msg(struct nl_sock *sk, struct nl_msg *msg)
+{
+    struct nlmsghdr *nlh;
+
+    nlh = nlmsg_hdr(msg);
+    if (nlh->nlmsg_pid == NL_AUTO_PORT)
+        nlh->nlmsg_pid = nl_socket_get_local_port(sk);
+
+    if (nlh->nlmsg_seq == NL_AUTO_SEQ)
+        nlh->nlmsg_seq = sk->s_seq_next++;
+
+    if (msg->nm_protocol == -1)
+        msg->nm_protocol = sk->s_proto;
+
+    nlh->nlmsg_flags |= NLM_F_REQUEST;
+
+    if (!(sk->s_flags & NL_NO_AUTO_ACK))
+        nlh->nlmsg_flags |= NLM_F_ACK;
+}
+
+int
+nl_send(struct nl_sock *sk, struct nl_msg *msg)
+{
+    struct iovec iov = {
+        .iov_base = (void *) nlmsg_hdr(msg),
+        .iov_len  = nlmsg_hdr(msg)->nlmsg_len,
+    };
+
+    return nl_send_iovec(sk, msg, &iov, 1);
+}
+
+int
+nl_send_auto(struct nl_sock *sk, struct nl_msg *msg)
+{
+    nl_complete_msg(sk, msg);
+
+    return nl_send(sk, msg);
+}
+
+int
+nl_recv(struct nl_sock *    sk,
+        struct sockaddr_nl *nla,
+        unsigned char **    buf,
+        struct ucred *      out_creds,
+        gboolean *          out_creds_has)
+{
+    ssize_t       n;
+    int           flags = 0;
+    struct iovec  iov;
+    struct msghdr msg = {
+        .msg_name    = (void *) nla,
+        .msg_namelen = sizeof(struct sockaddr_nl),
+        .msg_iov     = &iov,
+        .msg_iovlen  = 1,
+    };
+    struct ucred tmpcreds;
+    gboolean     tmpcreds_has = FALSE;
+    int          retval;
+    int          errsv;
+
+    nm_assert(nla);
+    nm_assert(buf && !*buf);
+    nm_assert(!out_creds_has == !out_creds);
+
+    if ((sk->s_flags & NL_MSG_PEEK)
+        || (!(sk->s_flags & NL_MSG_PEEK_EXPLICIT) && sk->s_bufsize == 0))
+        flags |= MSG_PEEK | MSG_TRUNC;
+
+    iov.iov_len  = sk->s_bufsize ?: (((size_t) nm_utils_getpagesize()) * 4u);
+    iov.iov_base = g_malloc(iov.iov_len);
+
+    if (out_creds && (sk->s_flags & NL_SOCK_PASSCRED)) {
+        msg.msg_controllen = CMSG_SPACE(sizeof(struct ucred));
+        msg.msg_control    = g_malloc(msg.msg_controllen);
+    }
+
+retry:
+    n = recvmsg(sk->s_fd, &msg, flags);
+    if (!n) {
+        retval = 0;
+        goto abort;
+    }
+
+    if (n < 0) {
+        errsv = errno;
+        if (errsv == EINTR)
+            goto retry;
+        retval = -nm_errno_from_native(errsv);
+        goto abort;
+    }
+
+    if (msg.msg_flags & MSG_CTRUNC) {
+        if (msg.msg_controllen == 0) {
+            retval = -NME_NL_MSG_TRUNC;
+            goto abort;
+        }
+
+        msg.msg_controllen *= 2;
+        msg.msg_control = g_realloc(msg.msg_control, msg.msg_controllen);
+        goto retry;
+    }
+
+    if (iov.iov_len < n || (msg.msg_flags & MSG_TRUNC)) {
+        /* respond with error to an incomplete message */
+        if (flags == 0) {
+            retval = -NME_NL_MSG_TRUNC;
+            goto abort;
+        }
+
+        /* Provided buffer is not long enough, enlarge it
+         * to size of n (which should be total length of the message)
+         * and try again. */
+        iov.iov_base = g_realloc(iov.iov_base, n);
+        iov.iov_len  = n;
+        flags        = 0;
+        goto retry;
+    }
+
+    if (flags != 0) {
+        /* Buffer is big enough, do the actual reading */
+        flags = 0;
+        goto retry;
+    }
+
+    if (msg.msg_namelen != sizeof(struct sockaddr_nl)) {
+        retval = -NME_UNSPEC;
+        goto abort;
+    }
+
+    if (out_creds && (sk->s_flags & NL_SOCK_PASSCRED)) {
+        struct cmsghdr *cmsg;
+
+        for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+            if (cmsg->cmsg_level != SOL_SOCKET)
+                continue;
+            if (cmsg->cmsg_type != SCM_CREDENTIALS)
+                continue;
+            memcpy(&tmpcreds, CMSG_DATA(cmsg), sizeof(tmpcreds));
+            tmpcreds_has = TRUE;
+            break;
+        }
+    }
+
+    retval = n;
+
+abort:
+    g_free(msg.msg_control);
+
+    if (retval <= 0) {
+        g_free(iov.iov_base);
+        return retval;
+    }
+
+    *buf = iov.iov_base;
+    if (out_creds && tmpcreds_has)
+        *out_creds = tmpcreds;
+    NM_SET_OUT(out_creds_has, tmpcreds_has);
+    return retval;
+}