diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libsystemd/sd-netlink/generic-netlink.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/libsystemd/sd-netlink/generic-netlink.c b/src/libsystemd/sd-netlink/generic-netlink.c new file mode 100644 index 0000000..f295fa9 --- /dev/null +++ b/src/libsystemd/sd-netlink/generic-netlink.c @@ -0,0 +1,176 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <linux/genetlink.h> + +#include "sd-netlink.h" + +#include "alloc-util.h" +#include "generic-netlink.h" +#include "netlink-internal.h" + +typedef struct { + const char* name; + uint8_t version; +} genl_family; + +static const genl_family genl_families[] = { + [SD_GENL_ID_CTRL] = { .name = "", .version = 1 }, + [SD_GENL_WIREGUARD] = { .name = "wireguard", .version = 1 }, + [SD_GENL_FOU] = { .name = "fou", .version = 1 }, + [SD_GENL_L2TP] = { .name = "l2tp", .version = 1 }, + [SD_GENL_MACSEC] = { .name = "macsec", .version = 1 }, + [SD_GENL_NL80211] = { .name = "nl80211", .version = 1 }, +}; + +int sd_genl_socket_open(sd_netlink **ret) { + return netlink_open_family(ret, NETLINK_GENERIC); +} +static int lookup_id(sd_netlink *nl, sd_genl_family family, uint16_t *id); + +static int genl_message_new(sd_netlink *nl, sd_genl_family family, uint16_t nlmsg_type, uint8_t cmd, sd_netlink_message **ret) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + const NLType *genl_cmd_type, *nl_type; + const NLTypeSystem *type_system; + struct genlmsghdr *genl; + size_t size; + int r; + + assert_return(nl->protocol == NETLINK_GENERIC, -EINVAL); + + r = type_system_get_type(&genl_family_type_system_root, &genl_cmd_type, family); + if (r < 0) + return r; + + r = message_new_empty(nl, &m); + if (r < 0) + return r; + + size = NLMSG_SPACE(sizeof(struct genlmsghdr)); + m->hdr = malloc0(size); + if (!m->hdr) + return -ENOMEM; + + m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + + type_get_type_system(genl_cmd_type, &type_system); + + r = type_system_get_type(type_system, &nl_type, cmd); + if (r < 0) + return r; + + m->hdr->nlmsg_len = size; + m->hdr->nlmsg_type = nlmsg_type; + + type_get_type_system(nl_type, &m->containers[0].type_system); + genl = NLMSG_DATA(m->hdr); + genl->cmd = cmd; + genl->version = genl_families[family].version; + + *ret = TAKE_PTR(m); + + return 0; +} + +int sd_genl_message_new(sd_netlink *nl, sd_genl_family family, uint8_t cmd, sd_netlink_message **ret) { + uint16_t id; + int r; + + r = lookup_id(nl, family, &id); + if (r < 0) + return r; + + return genl_message_new(nl, family, id, cmd, ret); +} + +static int lookup_id(sd_netlink *nl, sd_genl_family family, uint16_t *id) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL; + uint16_t u; + void *v; + int r; + + if (family == SD_GENL_ID_CTRL) { + *id = GENL_ID_CTRL; + return 0; + } + + v = hashmap_get(nl->genl_family_to_nlmsg_type, INT_TO_PTR(family)); + if (v) { + *id = PTR_TO_UINT(v); + return 0; + } + + r = sd_genl_message_new(nl, SD_GENL_ID_CTRL, CTRL_CMD_GETFAMILY, &req); + if (r < 0) + return r; + + r = sd_netlink_message_append_string(req, CTRL_ATTR_FAMILY_NAME, genl_families[family].name); + if (r < 0) + return r; + + r = sd_netlink_call(nl, req, 0, &reply); + if (r < 0) + return r; + + r = sd_netlink_message_read_u16(reply, CTRL_ATTR_FAMILY_ID, &u); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&nl->genl_family_to_nlmsg_type, NULL); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&nl->nlmsg_type_to_genl_family, NULL); + if (r < 0) + return r; + + r = hashmap_put(nl->genl_family_to_nlmsg_type, INT_TO_PTR(family), UINT_TO_PTR(u)); + if (r < 0) + return r; + + r = hashmap_put(nl->nlmsg_type_to_genl_family, UINT_TO_PTR(u), INT_TO_PTR(family)); + if (r < 0) + return r; + + *id = u; + return 0; +} + +int nlmsg_type_to_genl_family(const sd_netlink *nl, uint16_t type, sd_genl_family *ret) { + void *p; + + assert_return(nl, -EINVAL); + assert_return(nl->protocol == NETLINK_GENERIC, -EINVAL); + assert(ret); + + if (type == NLMSG_ERROR) + *ret = SD_GENL_ERROR; + else if (type == NLMSG_DONE) + *ret = SD_GENL_DONE; + else if (type == GENL_ID_CTRL) + *ret = SD_GENL_ID_CTRL; + else { + p = hashmap_get(nl->nlmsg_type_to_genl_family, UINT_TO_PTR(type)); + if (!p) + return -EOPNOTSUPP; + + *ret = PTR_TO_INT(p); + } + + return 0; +} + +int sd_genl_message_get_family(const sd_netlink *nl, const sd_netlink_message *m, sd_genl_family *family) { + uint16_t type; + int r; + + assert_return(m, -EINVAL); + assert_return(nl, -EINVAL); + assert_return(nl->protocol == NETLINK_GENERIC, -EINVAL); + assert_return(family, -EINVAL); + + r = sd_netlink_message_get_type(m, &type); + if (r < 0) + return r; + + return nlmsg_type_to_genl_family(nl, type, family); +} |