NetworkManager/dispatcher/nm-dispatcher-utils.c

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2008 - 2011 Red Hat, Inc.
 */

#include "libnm/nm-default-client.h"

#include "nm-dispatcher-utils.h"

#include "nm-dbus-interface.h"
#include "nm-connection.h"
#include "nm-setting-ip4-config.h"
#include "nm-setting-ip6-config.h"
#include "nm-setting-connection.h"

#include "nm-libnm-core-aux/nm-dispatcher-api.h"
#include "nm-utils.h"

/*****************************************************************************/

static gboolean
_is_valid_key(const char *line, gssize len)
{
    gsize i, l;
    char  ch;

    if (!line)
        return FALSE;

    if (len < 0)
        len = strlen(line);

    if (len == 0)
        return FALSE;

    ch = line[0];
    if (!(ch >= 'A' && ch <= 'Z') && !NM_IN_SET(ch, '_'))
        return FALSE;

    l = (gsize) len;

    for (i = 1; i < l; i++) {
        ch = line[i];

        if (!(ch >= 'A' && ch <= 'Z') && !(ch >= '0' && ch <= '9') && !NM_IN_SET(ch, '_'))
            return FALSE;
    }

    return TRUE;
}

static gboolean
_is_valid_line(const char *line)
{
    const char *d;

    if (!line)
        return FALSE;

    d = strchr(line, '=');
    if (!d || d == line)
        return FALSE;

    return _is_valid_key(line, d - line);
}

static char *
_sanitize_var_name(const char *key)
{
    char *sanitized;

    nm_assert(key);

    if (!key[0])
        return NULL;

    sanitized = g_ascii_strup(key, -1);
    if (!NM_STRCHAR_ALL(sanitized,
                        ch,
                        (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9')
                            || NM_IN_SET(ch, '_'))) {
        g_free(sanitized);
        return NULL;
    }

    nm_assert(_is_valid_key(sanitized, -1));
    return sanitized;
}

static void
_items_add_str_take(GPtrArray *items, char *line)
{
    nm_assert(items);
    nm_assert(_is_valid_line(line));

    g_ptr_array_add(items, line);
}

static void
_items_add_str(GPtrArray *items, const char *line)
{
    _items_add_str_take(items, g_strdup(line));
}

static void
_items_add_key(GPtrArray *items, const char *prefix, const char *key, const char *value)
{
    nm_assert(items);
    nm_assert(_is_valid_key(key, -1));
    nm_assert(value);

    _items_add_str_take(items, g_strconcat(prefix ?: "", key, "=", value, NULL));
}

static void
_items_add_key0(GPtrArray *items, const char *prefix, const char *key, const char *value)
{
    nm_assert(items);
    nm_assert(_is_valid_key(key, -1));

    if (!value) {
        /* for convenience, allow NULL values to indicate to skip the line. */
        return;
    }

    _items_add_str_take(items, g_strconcat(prefix ?: "", key, "=", value, NULL));
}

G_GNUC_PRINTF(2, 3)
static void
_items_add_printf(GPtrArray *items, const char *fmt, ...)
{
    va_list ap;
    char *  line;

    nm_assert(items);
    nm_assert(fmt);

    va_start(ap, fmt);
    line = g_strdup_vprintf(fmt, ap);
    va_end(ap);
    _items_add_str_take(items, line);
}

static void
_items_add_strv(GPtrArray *items, const char *prefix, const char *key, const char *const *values)
{
    gboolean has;
    guint    i;
    GString *str;

    nm_assert(items);
    nm_assert(_is_valid_key(key, -1));

    if (!values || !values[0]) {
        /* Only add an item if the list of @values is not empty */
        return;
    }

    str = g_string_new(NULL);

    if (prefix)
        g_string_append(str, prefix);
    g_string_append(str, key);
    g_string_append_c(str, '=');

    has = FALSE;
    for (i = 0; values[i]; i++) {
        if (!values[i][0])
            continue;
        if (has)
            g_string_append_c(str, ' ');
        else
            has = TRUE;
        g_string_append(str, values[i]);
    }

    _items_add_str_take(items, g_string_free(str, FALSE));
}

/*****************************************************************************/

static void
construct_proxy_items(GPtrArray *items, GVariant *proxy_config, const char *prefix)
{
    GVariant *variant;

    nm_assert(items);

    if (!proxy_config)
        return;

    variant = g_variant_lookup_value(proxy_config, "pac-url", G_VARIANT_TYPE_STRING);
    if (variant) {
        _items_add_key(items, prefix, "PROXY_PAC_URL", g_variant_get_string(variant, NULL));
        g_variant_unref(variant);
    }

    variant = g_variant_lookup_value(proxy_config, "pac-script", G_VARIANT_TYPE_STRING);
    if (variant) {
        _items_add_key(items, prefix, "PROXY_PAC_SCRIPT", g_variant_get_string(variant, NULL));
        g_variant_unref(variant);
    }
}

static void
construct_ip_items(GPtrArray *items, int addr_family, GVariant *ip_config, const char *prefix)
{
    GVariant *val;
    guint     i;
    guint     nroutes = 0;
    char      four_or_six;

    if (!ip_config)
        return;

    if (!prefix)
        prefix = "";

    four_or_six = nm_utils_addr_family_to_char(addr_family);

    val = g_variant_lookup_value(ip_config,
                                 "addresses",
                                 addr_family == AF_INET ? G_VARIANT_TYPE("aau")
                                                        : G_VARIANT_TYPE("a(ayuay)"));
    if (val) {
        gs_unref_ptrarray GPtrArray *addresses    = NULL;
        gs_free char *               gateway_free = NULL;
        const char *                 gateway;

        if (addr_family == AF_INET)
            addresses = nm_utils_ip4_addresses_from_variant(val, &gateway_free);
        else
            addresses = nm_utils_ip6_addresses_from_variant(val, &gateway_free);

        gateway = gateway_free ?: "0.0.0.0";

        if (addresses && addresses->len) {
            for (i = 0; i < addresses->len; i++) {
                NMIPAddress *addr = addresses->pdata[i];

                _items_add_printf(items,
                                  "%sIP%c_ADDRESS_%d=%s/%d %s",
                                  prefix,
                                  four_or_six,
                                  i,
                                  nm_ip_address_get_address(addr),
                                  nm_ip_address_get_prefix(addr),
                                  gateway);
            }

            _items_add_printf(items,
                              "%sIP%c_NUM_ADDRESSES=%u",
                              prefix,
                              four_or_six,
                              addresses->len);
        }

        _items_add_key(items,
                       prefix,
                       addr_family == AF_INET ? "IP4_GATEWAY" : "IP6_GATEWAY",
                       gateway);

        g_variant_unref(val);
    }

    val = g_variant_lookup_value(ip_config,
                                 "nameservers",
                                 addr_family == AF_INET ? G_VARIANT_TYPE("au")
                                                        : G_VARIANT_TYPE("aay"));
    if (val) {
        gs_strfreev char **v = NULL;

        if (addr_family == AF_INET)
            v = nm_utils_ip4_dns_from_variant(val);
        else
            v = nm_utils_ip6_dns_from_variant(val);
        _items_add_strv(items,
                        prefix,
                        addr_family == AF_INET ? "IP4_NAMESERVERS" : "IP6_NAMESERVERS",
                        NM_CAST_STRV_CC(v));
        g_variant_unref(val);
    }

    val = g_variant_lookup_value(ip_config, "domains", G_VARIANT_TYPE_STRING_ARRAY);
    if (val) {
        gs_free const char **v = NULL;

        v = g_variant_get_strv(val, NULL);
        _items_add_strv(items, prefix, addr_family == AF_INET ? "IP4_DOMAINS" : "IP6_DOMAINS", v);
        g_variant_unref(val);
    }

    if (addr_family == AF_INET) {
        val = g_variant_lookup_value(ip_config, "wins-servers", G_VARIANT_TYPE("au"));
        if (val) {
            gs_strfreev char **v = NULL;

            v = nm_utils_ip4_dns_from_variant(val);
            _items_add_strv(items, prefix, "IP4_WINS_SERVERS", NM_CAST_STRV_CC(v));
            g_variant_unref(val);
        }
    }

    val = g_variant_lookup_value(ip_config,
                                 "routes",
                                 addr_family == AF_INET ? G_VARIANT_TYPE("aau")
                                                        : G_VARIANT_TYPE("a(ayuayu)"));
    if (val) {
        gs_unref_ptrarray GPtrArray *routes = NULL;

        if (addr_family == AF_INET)
            routes = nm_utils_ip4_routes_from_variant(val);
        else
            routes = nm_utils_ip6_routes_from_variant(val);

        if (routes && routes->len > 0) {
            const char *const DEFAULT_GW = addr_family == AF_INET ? "0.0.0.0" : "::";

            nroutes = routes->len;

            for (i = 0; i < routes->len; i++) {
                NMIPRoute *route = routes->pdata[i];

                _items_add_printf(items,
                                  "%sIP%c_ROUTE_%u=%s/%d %s %u",
                                  prefix,
                                  four_or_six,
                                  i,
                                  nm_ip_route_get_dest(route),
                                  nm_ip_route_get_prefix(route),
                                  nm_ip_route_get_next_hop(route) ?: DEFAULT_GW,
                                  (guint) NM_MAX((gint64) 0, nm_ip_route_get_metric(route)));
            }
        }

        g_variant_unref(val);
    }
    if (nroutes > 0 || addr_family == AF_INET) {
        /* we also set IP4_NUM_ROUTES=0, but don't do so for addresses and IPv6 routes.
         * Historic reasons. */
        _items_add_printf(items, "%sIP%c_NUM_ROUTES=%u", prefix, four_or_six, nroutes);
    }
}

static void
construct_device_dhcp_items(GPtrArray *items, int addr_family, GVariant *dhcp_config)
{
    GVariantIter     iter;
    const char *     key;
    GVariant *       val;
    char             four_or_six;
    gboolean         found_unknown_245         = FALSE;
    gs_unref_variant GVariant *private_245_val = NULL;

    if (!dhcp_config)
        return;

    if (!g_variant_is_of_type(dhcp_config, G_VARIANT_TYPE_VARDICT))
        return;

    four_or_six = nm_utils_addr_family_to_char(addr_family);

    g_variant_iter_init(&iter, dhcp_config);
    while (g_variant_iter_next(&iter, "{&sv}", &key, &val)) {
        if (g_variant_is_of_type(val, G_VARIANT_TYPE_STRING)) {
            gs_free char *ucased = NULL;

            ucased = _sanitize_var_name(key);
            if (ucased) {
                _items_add_printf(items,
                                  "DHCP%c_%s=%s",
                                  four_or_six,
                                  ucased,
                                  g_variant_get_string(val, NULL));

                /* MS Azure sends the server endpoint in the dhcp private
                 * option 245. cloud-init searches the Azure server endpoint
                 * value looking for the standard dhclient label used for
                 * that option, which is "unknown_245".
                 * The 11-dhclient script shipped with Fedora and RHEL dhcp
                 * package converts our dispatcher environment vars to the
                 * dhclient ones (new_<some_option>) and calls dhclient hook
                 * scripts.
                 * Let's make cloud-init happy and let's duplicate the dhcp
                 * option 245 with the legacy name of the default dhclient
                 * label also when using the internal client.
                 * Note however that the dhclient plugin will have unknown_
                 * labels represented as ascii string when possible, falling
                 * back to hex string otherwise.
                 * private_ labels instead are always in hex string format.
                 * This shouldn't affect the MS Azure server endpoint value,
                 * as it usually belongs to the 240.0.0.0/4 network and so
                 * is always represented as an hex string. Moreover, cloudinit
                 * code checks just for an hex value in unknown_245.
                 */
                if (addr_family == AF_INET) {
                    if (nm_streq(key, "private_245"))
                        private_245_val = g_variant_ref(val);
                    else if (nm_streq(key, "unknown_245"))
                        found_unknown_245 = true;
                }
            }
        }
        g_variant_unref(val);
    }

    if (private_245_val != NULL && !found_unknown_245) {
        _items_add_printf(items,
                          "DHCP4_UNKNOWN_245=%s",
                          g_variant_get_string(private_245_val, NULL));
    }
}

/*****************************************************************************/

char **
nm_dispatcher_utils_construct_envp(const char * action,
                                   GVariant *   connection_dict,
                                   GVariant *   connection_props,
                                   GVariant *   device_props,
                                   GVariant *   device_proxy_props,
                                   GVariant *   device_ip4_props,
                                   GVariant *   device_ip6_props,
                                   GVariant *   device_dhcp4_props,
                                   GVariant *   device_dhcp6_props,
                                   const char * connectivity_state,
                                   const char * vpn_ip_iface,
                                   GVariant *   vpn_proxy_props,
                                   GVariant *   vpn_ip4_props,
                                   GVariant *   vpn_ip6_props,
                                   char **      out_iface,
                                   const char **out_error_message)
{
    const char *      iface    = NULL;
    const char *      ip_iface = NULL;
    const char *      uuid     = NULL;
    const char *      id       = NULL;
    const char *      path     = NULL;
    const char *      filename = NULL;
    gboolean          external;
    NMDeviceState     dev_state = NM_DEVICE_STATE_UNKNOWN;
    GVariant *        variant;
    gs_unref_ptrarray GPtrArray *items = NULL;
    const char *                 error_message_backup;

    if (!out_error_message)
        out_error_message = &error_message_backup;

    g_return_val_if_fail(action != NULL, NULL);
    g_return_val_if_fail(out_iface != NULL, NULL);
    g_return_val_if_fail(*out_iface == NULL, NULL);

    items = g_ptr_array_new_with_free_func(g_free);

    /* Hostname and connectivity changes don't require a device nor contain a connection */
    if (NM_IN_STRSET(action, NMD_ACTION_HOSTNAME, NMD_ACTION_CONNECTIVITY_CHANGE))
        goto done;

    /* Connection properties */
    if (g_variant_lookup(connection_props, NMD_CONNECTION_PROPS_PATH, "&o", &path))
        _items_add_key(items, NULL, "CONNECTION_DBUS_PATH", path);

    if (g_variant_lookup(connection_props, NMD_CONNECTION_PROPS_EXTERNAL, "b", &external)
        && external)
        _items_add_str(items, "CONNECTION_EXTERNAL=1");

    if (g_variant_lookup(connection_props, NMD_CONNECTION_PROPS_FILENAME, "&s", &filename))
        _items_add_key(items, NULL, "CONNECTION_FILENAME", filename);

    /* Canonicalize the VPN interface name; "" is used when passing it through
     * D-Bus so make sure that's fixed up here.
     */
    if (vpn_ip_iface && !vpn_ip_iface[0])
        vpn_ip_iface = NULL;

    if (!g_variant_lookup(device_props, NMD_DEVICE_PROPS_INTERFACE, "&s", &iface)) {
        *out_error_message = "Missing or invalid required value " NMD_DEVICE_PROPS_INTERFACE "!";
        return NULL;
    }
    if (!*iface)
        iface = NULL;

    variant = g_variant_lookup_value(device_props, NMD_DEVICE_PROPS_IP_INTERFACE, NULL);
    if (variant) {
        if (!g_variant_is_of_type(variant, G_VARIANT_TYPE_STRING)) {
            *out_error_message = "Invalid value " NMD_DEVICE_PROPS_IP_INTERFACE "!";
            return NULL;
        }
        g_variant_unref(variant);
        (void) g_variant_lookup(device_props, NMD_DEVICE_PROPS_IP_INTERFACE, "&s", &ip_iface);
    }

    if (!g_variant_lookup(device_props, NMD_DEVICE_PROPS_TYPE, "u", NULL)) {
        *out_error_message = "Missing or invalid required value " NMD_DEVICE_PROPS_TYPE "!";
        return NULL;
    }

    variant = g_variant_lookup_value(device_props, NMD_DEVICE_PROPS_STATE, G_VARIANT_TYPE_UINT32);
    if (!variant) {
        *out_error_message = "Missing or invalid required value " NMD_DEVICE_PROPS_STATE "!";
        return NULL;
    }
    dev_state = g_variant_get_uint32(variant);
    g_variant_unref(variant);

    if (!g_variant_lookup(device_props, NMD_DEVICE_PROPS_PATH, "o", NULL)) {
        *out_error_message = "Missing or invalid required value " NMD_DEVICE_PROPS_PATH "!";
        return NULL;
    }

    {
        gs_unref_variant GVariant *con_setting = NULL;

        con_setting = g_variant_lookup_value(connection_dict,
                                             NM_SETTING_CONNECTION_SETTING_NAME,
                                             NM_VARIANT_TYPE_SETTING);
        if (!con_setting) {
            *out_error_message = "Failed to read connection setting";
            return NULL;
        }

        if (!g_variant_lookup(con_setting, NM_SETTING_CONNECTION_UUID, "&s", &uuid)) {
            *out_error_message = "Connection hash did not contain the UUID";
            return NULL;
        }

        if (!g_variant_lookup(con_setting, NM_SETTING_CONNECTION_ID, "&s", &id)) {
            *out_error_message = "Connection hash did not contain the ID";
            return NULL;
        }

        _items_add_key0(items, NULL, "CONNECTION_UUID", uuid);
        _items_add_key0(items, NULL, "CONNECTION_ID", id);
        _items_add_key0(items, NULL, "DEVICE_IFACE", iface);
        _items_add_key0(items, NULL, "DEVICE_IP_IFACE", ip_iface);
    }

    /* Device items aren't valid if the device isn't activated */
    if (iface && dev_state == NM_DEVICE_STATE_ACTIVATED) {
        construct_proxy_items(items, device_proxy_props, NULL);
        construct_ip_items(items, AF_INET, device_ip4_props, NULL);
        construct_ip_items(items, AF_INET6, device_ip6_props, NULL);
        construct_device_dhcp_items(items, AF_INET, device_dhcp4_props);
        construct_device_dhcp_items(items, AF_INET6, device_dhcp6_props);
    }

    if (vpn_ip_iface) {
        _items_add_key(items, NULL, "VPN_IP_IFACE", vpn_ip_iface);
        construct_proxy_items(items, vpn_proxy_props, "VPN_");
        construct_ip_items(items, AF_INET, vpn_ip4_props, "VPN_");
        construct_ip_items(items, AF_INET6, vpn_ip6_props, "VPN_");
    }

    /* Backwards compat: 'iface' is set in this order:
     * 1) VPN interface name
     * 2) Device IP interface name
     * 3) Device interface anme
     */
    if (vpn_ip_iface)
        *out_iface = g_strdup(vpn_ip_iface);
    else if (ip_iface)
        *out_iface = g_strdup(ip_iface);
    else
        *out_iface = g_strdup(iface);

done:
    /* The connectivity_state value will only be meaningful for 'connectivity-change' events
     * (otherwise it will be "UNKNOWN"), so we only set the environment variable in those cases.
     */
    if (!NM_IN_STRSET(connectivity_state, NULL, "UNKNOWN"))
        _items_add_key(items, NULL, "CONNECTIVITY_STATE", connectivity_state);

    _items_add_key0(items, NULL, "PATH", g_getenv("PATH"));

    _items_add_key(items, NULL, "NM_DISPATCHER_ACTION", action);

    *out_error_message = NULL;
    g_ptr_array_add(items, NULL);
    return (char **) g_ptr_array_free(g_steal_pointer(&items), FALSE);
}