diff options
| -rw-r--r-- | include/linux/drbd_genl.h | 349 | ||||
| -rw-r--r-- | include/linux/drbd_genl_api.h | 55 | ||||
| -rw-r--r-- | include/linux/genl_magic_func.h | 417 | ||||
| -rw-r--r-- | include/linux/genl_magic_struct.h | 260 |
4 files changed, 1081 insertions, 0 deletions
diff --git a/include/linux/drbd_genl.h b/include/linux/drbd_genl.h new file mode 100644 index 00000000000..84e16848f7a --- /dev/null +++ b/include/linux/drbd_genl.h @@ -0,0 +1,349 @@ +/* + * General overview: + * full generic netlink message: + * |nlmsghdr|genlmsghdr|<payload> + * + * payload: + * |optional fixed size family header|<sequence of netlink attributes> + * + * sequence of netlink attributes: + * I chose to have all "top level" attributes NLA_NESTED, + * corresponding to some real struct. + * So we have a sequence of |tla, len|<nested nla sequence> + * + * nested nla sequence: + * may be empty, or contain a sequence of netlink attributes + * representing the struct fields. + * + * The tag number of any field (regardless of containing struct) + * will be available as T_ ## field_name, + * so you cannot have the same field name in two differnt structs. + * + * The tag numbers themselves are per struct, though, + * so should always begin at 1 (not 0, that is the special "NLA_UNSPEC" type, + * which we won't use here). + * The tag numbers are used as index in the respective nla_policy array. + * + * GENL_struct(tag_name, tag_number, struct name, struct fields) - struct and policy + * genl_magic_struct.h + * generates the struct declaration, + * generates an entry in the tla enum, + * genl_magic_func.h + * generates an entry in the static tla policy + * with .type = NLA_NESTED + * generates the static <struct_name>_nl_policy definition, + * and static conversion functions + * + * genl_magic_func.h + * + * GENL_mc_group(group) + * genl_magic_struct.h + * does nothing + * genl_magic_func.h + * defines and registers the mcast group, + * and provides a send helper + * + * GENL_notification(op_name, op_num, mcast_group, tla list) + * These are notifications to userspace. + * + * genl_magic_struct.h + * generates an entry in the genl_ops enum, + * genl_magic_func.h + * does nothing + * + * mcast group: the name of the mcast group this notification should be + * expected on + * tla list: the list of expected top level attributes, + * for documentation and sanity checking. + * + * GENL_op(op_name, op_num, flags and handler, tla list) - "genl operations" + * These are requests from userspace. + * + * _op and _notification share the same "number space", + * op_nr will be assigned to "genlmsghdr->cmd" + * + * genl_magic_struct.h + * generates an entry in the genl_ops enum, + * genl_magic_func.h + * generates an entry in the static genl_ops array, + * and static register/unregister functions to + * genl_register_family_with_ops(). + * + * flags and handler: + * GENL_op_init( .doit = x, .dumpit = y, .flags = something) + * GENL_doit(x) => .dumpit = NULL, .flags = GENL_ADMIN_PERM + * tla list: the list of expected top level attributes, + * for documentation and sanity checking. + */ + +/* + * STRUCTS + */ + +/* this is sent kernel -> userland on various error conditions, and contains + * informational textual info, which is supposedly human readable. + * The computer relevant return code is in the drbd_genlmsghdr. + */ +GENL_struct(DRBD_NLA_CFG_REPLY, 1, drbd_cfg_reply, + /* "arbitrary" size strings, nla_policy.len = 0 */ + __str_field(1, GENLA_F_MANDATORY, info_text, 0) +) + +/* Configuration requests typically need a context to operate on. + * Possible keys are device minor (fits in the drbd_genlmsghdr), + * the replication link (aka connection) name, + * and/or the replication group (aka resource) name, + * and the volume id within the resource. */ +GENL_struct(DRBD_NLA_CFG_CONTEXT, 2, drbd_cfg_context, + /* currently only 256 volumes per group, + * but maybe we still change that */ + __u32_field(1, GENLA_F_MANDATORY, ctx_volume) + __str_field(2, GENLA_F_MANDATORY, ctx_conn_name, 128) +) + +GENL_struct(DRBD_NLA_DISK_CONF, 3, disk_conf, + __u64_field(1, GENLA_F_MANDATORY, disk_size) + __str_field(2, GENLA_F_REQUIRED, backing_dev, 128) + __str_field(3, GENLA_F_REQUIRED, meta_dev, 128) + __u32_field(4, GENLA_F_REQUIRED, meta_dev_idx) + __u32_field(5, GENLA_F_MANDATORY, max_bio_bvecs) + __u32_field(6, GENLA_F_MANDATORY, on_io_error) + __u32_field(7, GENLA_F_MANDATORY, fencing) + __flg_field(8, GENLA_F_MANDATORY, no_disk_barrier) + __flg_field(9, GENLA_F_MANDATORY, no_disk_flush) + __flg_field(10, GENLA_F_MANDATORY, no_disk_drain) + __flg_field(11, GENLA_F_MANDATORY, no_md_flush) + __flg_field(12, GENLA_F_MANDATORY, use_bmbv) +) + +GENL_struct(DRBD_NLA_SYNCER_CONF, 4, syncer_conf, + __u32_field(1, GENLA_F_MANDATORY, rate) + __u32_field(2, GENLA_F_MANDATORY, after) + __u32_field(3, GENLA_F_MANDATORY, al_extents) + __str_field(4, GENLA_F_MANDATORY, cpu_mask, 32) + __str_field(5, GENLA_F_MANDATORY, verify_alg, SHARED_SECRET_MAX) + __str_field(6, GENLA_F_MANDATORY, csums_alg, SHARED_SECRET_MAX) + __flg_field(7, GENLA_F_MANDATORY, use_rle) + __u32_field(8, GENLA_F_MANDATORY, on_no_data) + __u32_field(9, GENLA_F_MANDATORY, c_plan_ahead) + __u32_field(10, GENLA_F_MANDATORY, c_delay_target) + __u32_field(11, GENLA_F_MANDATORY, c_fill_target) + __u32_field(12, GENLA_F_MANDATORY, c_max_rate) + __u32_field(13, GENLA_F_MANDATORY, c_min_rate) +) + +GENL_struct(DRBD_NLA_NET_CONF, 5, net_conf, + __str_field(1, GENLA_F_MANDATORY | GENLA_F_SENSITIVE, + shared_secret, SHARED_SECRET_MAX) + __str_field(2, GENLA_F_MANDATORY, cram_hmac_alg, SHARED_SECRET_MAX) + __str_field(3, GENLA_F_MANDATORY, integrity_alg, SHARED_SECRET_MAX) + __str_field(4, GENLA_F_REQUIRED, my_addr, 128) + __str_field(5, GENLA_F_REQUIRED, peer_addr, 128) + __u32_field(6, GENLA_F_REQUIRED, wire_protocol) + __u32_field(7, GENLA_F_MANDATORY, try_connect_int) + __u32_field(8, GENLA_F_MANDATORY, timeout) + __u32_field(9, GENLA_F_MANDATORY, ping_int) + __u32_field(10, GENLA_F_MANDATORY, ping_timeo) + __u32_field(11, GENLA_F_MANDATORY, sndbuf_size) + __u32_field(12, GENLA_F_MANDATORY, rcvbuf_size) + __u32_field(13, GENLA_F_MANDATORY, ko_count) + __u32_field(14, GENLA_F_MANDATORY, max_buffers) + __u32_field(15, GENLA_F_MANDATORY, max_epoch_size) + __u32_field(16, GENLA_F_MANDATORY, unplug_watermark) + __u32_field(17, GENLA_F_MANDATORY, after_sb_0p) + __u32_field(18, GENLA_F_MANDATORY, after_sb_1p) + __u32_field(19, GENLA_F_MANDATORY, after_sb_2p) + __u32_field(20, GENLA_F_MANDATORY, rr_conflict) + __u32_field(21, GENLA_F_MANDATORY, on_congestion) + __u32_field(22, GENLA_F_MANDATORY, cong_fill) + __u32_field(23, GENLA_F_MANDATORY, cong_extents) + __flg_field(24, GENLA_F_MANDATORY, two_primaries) + __flg_field(25, GENLA_F_MANDATORY, want_lose) + __flg_field(26, GENLA_F_MANDATORY, no_cork) + __flg_field(27, GENLA_F_MANDATORY, always_asbp) + __flg_field(28, GENLA_F_MANDATORY, dry_run) +) + +GENL_struct(DRBD_NLA_SET_ROLE_PARMS, 6, set_role_parms, + __flg_field(1, GENLA_F_MANDATORY, assume_uptodate) +) + +GENL_struct(DRBD_NLA_RESIZE_PARMS, 7, resize_parms, + __u64_field(1, GENLA_F_MANDATORY, resize_size) + __flg_field(2, GENLA_F_MANDATORY, resize_force) + __flg_field(3, GENLA_F_MANDATORY, no_resync) +) + +GENL_struct(DRBD_NLA_STATE_INFO, 8, state_info, + /* the reason of the broadcast, + * if this is an event triggered broadcast. */ + __u32_field(1, GENLA_F_MANDATORY, sib_reason) + __u32_field(2, GENLA_F_REQUIRED, current_state) + __u64_field(3, GENLA_F_MANDATORY, capacity) + __u64_field(4, GENLA_F_MANDATORY, ed_uuid) + + /* These are for broadcast from after state change work. + * prev_state and new_state are from the moment the state change took + * place, new_state is not neccessarily the same as current_state, + * there may have been more state changes since. Which will be + * broadcasted soon, in their respective after state change work. */ + __u32_field(5, GENLA_F_MANDATORY, prev_state) + __u32_field(6, GENLA_F_MANDATORY, new_state) + + /* if we have a local disk: */ + __bin_field(7, GENLA_F_MANDATORY, uuids, (UI_SIZE*sizeof(__u64))) + __u32_field(8, GENLA_F_MANDATORY, disk_flags) + __u64_field(9, GENLA_F_MANDATORY, bits_total) + __u64_field(10, GENLA_F_MANDATORY, bits_oos) + /* and in case resync or online verify is active */ + __u64_field(11, GENLA_F_MANDATORY, bits_rs_total) + __u64_field(12, GENLA_F_MANDATORY, bits_rs_failed) + + /* for pre and post notifications of helper execution */ + __str_field(13, GENLA_F_MANDATORY, helper, 32) + __u32_field(14, GENLA_F_MANDATORY, helper_exit_code) +) + +GENL_struct(DRBD_NLA_START_OV_PARMS, 9, start_ov_parms, + __u64_field(1, GENLA_F_MANDATORY, ov_start_sector) +) + +GENL_struct(DRBD_NLA_NEW_C_UUID_PARMS, 10, new_c_uuid_parms, + __flg_field(1, GENLA_F_MANDATORY, clear_bm) +) + +GENL_struct(DRBD_NLA_TIMEOUT_PARMS, 11, timeout_parms, + __u32_field(1, GENLA_F_REQUIRED, timeout_type) +) + +GENL_struct(DRBD_NLA_DISCONNECT_PARMS, 12, disconnect_parms, + __flg_field(1, GENLA_F_MANDATORY, force_disconnect) +) + +/* + * Notifications and commands (genlmsghdr->cmd) + */ +GENL_mc_group(events) + + /* kernel -> userspace announcement of changes */ +GENL_notification( + DRBD_EVENT, 1, events, + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_STATE_INFO, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_NET_CONF, GENLA_F_MANDATORY) + GENL_tla_expected(DRBD_NLA_DISK_CONF, GENLA_F_MANDATORY) + GENL_tla_expected(DRBD_NLA_SYNCER_CONF, GENLA_F_MANDATORY) +) + + /* query kernel for specific or all info */ +GENL_op( + DRBD_ADM_GET_STATUS, 2, + GENL_op_init( + .doit = drbd_adm_get_status, + .dumpit = drbd_adm_get_status_all, + /* anyone may ask for the status, + * it is broadcasted anyways */ + ), + /* To select the object .doit. + * Or a subset of objects in .dumpit. */ + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_MANDATORY) +) + +#if 0 + /* TO BE DONE */ + /* create or destroy resources, aka replication groups */ +GENL_op(DRBD_ADM_CREATE_RESOURCE, 3, GENL_doit(drbd_adm_create_resource), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_DELETE_RESOURCE, 4, GENL_doit(drbd_adm_delete_resource), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +#endif + + /* add DRBD minor devices as volumes to resources */ +GENL_op(DRBD_ADM_ADD_MINOR, 5, GENL_doit(drbd_adm_add_minor), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_DEL_MINOR, 6, GENL_doit(drbd_adm_delete_minor), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) + + /* add or delete replication links to resources */ +GENL_op(DRBD_ADM_ADD_LINK, 7, GENL_doit(drbd_adm_create_connection), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_DEL_LINK, 8, GENL_doit(drbd_adm_delete_connection), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) + + /* operates on replication links */ +GENL_op(DRBD_ADM_SYNCER, 9, + GENL_doit(drbd_adm_syncer), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_SYNCER_CONF, GENLA_F_MANDATORY) +) + +GENL_op( + DRBD_ADM_CONNECT, 10, + GENL_doit(drbd_adm_connect), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_NET_CONF, GENLA_F_REQUIRED) +) + +GENL_op(DRBD_ADM_DISCONNECT, 11, GENL_doit(drbd_adm_disconnect), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) + + /* operates on minors */ +GENL_op(DRBD_ADM_ATTACH, 12, + GENL_doit(drbd_adm_attach), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_DISK_CONF, GENLA_F_REQUIRED) +) + +GENL_op( + DRBD_ADM_RESIZE, 13, + GENL_doit(drbd_adm_resize), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_RESIZE_PARMS, GENLA_F_MANDATORY) +) + + /* operates on all volumes within a resource */ +GENL_op( + DRBD_ADM_PRIMARY, 14, + GENL_doit(drbd_adm_set_role), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_SET_ROLE_PARMS, GENLA_F_REQUIRED) +) + +GENL_op( + DRBD_ADM_SECONDARY, 15, + GENL_doit(drbd_adm_set_role), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_SET_ROLE_PARMS, GENLA_F_REQUIRED) +) + +GENL_op( + DRBD_ADM_NEW_C_UUID, 16, + GENL_doit(drbd_adm_new_c_uuid), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED) + GENL_tla_expected(DRBD_NLA_NEW_C_UUID_PARMS, GENLA_F_MANDATORY) +) + +GENL_op( + DRBD_ADM_START_OV, 17, + GENL_doit(drbd_adm_start_ov), + GENL_tla_expected(DRBD_NLA_START_OV_PARMS, GENLA_F_MANDATORY) +) + +GENL_op(DRBD_ADM_DETACH, 18, GENL_doit(drbd_adm_detach), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_INVALIDATE, 19, GENL_doit(drbd_adm_invalidate), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_INVAL_PEER, 20, GENL_doit(drbd_adm_invalidate_peer), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_PAUSE_SYNC, 21, GENL_doit(drbd_adm_pause_sync), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_RESUME_SYNC, 22, GENL_doit(drbd_adm_resume_sync), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_SUSPEND_IO, 23, GENL_doit(drbd_adm_suspend_io), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_RESUME_IO, 24, GENL_doit(drbd_adm_resume_io), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_OUTDATE, 25, GENL_doit(drbd_adm_outdate), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) +GENL_op(DRBD_ADM_GET_TIMEOUT_TYPE, 26, GENL_doit(drbd_adm_get_timeout_type), + GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)) diff --git a/include/linux/drbd_genl_api.h b/include/linux/drbd_genl_api.h new file mode 100644 index 00000000000..9ef50d51e34 --- /dev/null +++ b/include/linux/drbd_genl_api.h @@ -0,0 +1,55 @@ +#ifndef DRBD_GENL_STRUCT_H +#define DRBD_GENL_STRUCT_H + +/** + * struct drbd_genlmsghdr - DRBD specific header used in NETLINK_GENERIC requests + * @minor: + * For admin requests (user -> kernel): which minor device to operate on. + * For (unicast) replies or informational (broadcast) messages + * (kernel -> user): which minor device the information is about. + * If we do not operate on minors, but on connections or resources, + * the minor value shall be (~0), and the attribute DRBD_NLA_CFG_CONTEXT + * is used instead. + * @flags: possible operation modifiers (relevant only for user->kernel): + * DRBD_GENL_F_SET_DEFAULTS + * @volume: + * When creating a new minor (adding it to a resource), the resource needs + * to know which volume number within the resource this is supposed to be. + * The volume number corresponds to the same volume number on the remote side, + * whereas the minor number on the remote side may be different + * (union with flags). + * @ret_code: kernel->userland unicast cfg reply return code (union with flags); + */ +struct drbd_genlmsghdr { + __u32 minor; + union { + __u32 flags; + __s32 ret_code; + }; +}; + +/* To be used in drbd_genlmsghdr.flags */ +enum { + DRBD_GENL_F_SET_DEFAULTS = 1, +}; + +enum drbd_state_info_bcast_reason { + SIB_GET_STATUS_REPLY = 1, + SIB_STATE_CHANGE = 2, + SIB_HELPER_PRE = 3, + SIB_HELPER_POST = 4, + SIB_SYNC_PROGRESS = 5, +}; + +/* hack around predefined gcc/cpp "linux=1", + * we cannot possibly include <1/drbd_genl.h> */ +#undef linux + +#include <linux/drbd.h> +#define GENL_MAGIC_VERSION API_VERSION +#define GENL_MAGIC_FAMILY drbd +#define GENL_MAGIC_FAMILY_HDRSZ sizeof(struct drbd_genlmsghdr) +#define GENL_MAGIC_INCLUDE_FILE <linux/drbd_genl.h> +#include <linux/genl_magic_struct.h> + +#endif diff --git a/include/linux/genl_magic_func.h b/include/linux/genl_magic_func.h new file mode 100644 index 00000000000..8a86f659d36 --- /dev/null +++ b/include/linux/genl_magic_func.h @@ -0,0 +1,417 @@ +#ifndef GENL_MAGIC_FUNC_H +#define GENL_MAGIC_FUNC_H + +#include <linux/genl_magic_struct.h> + +/* + * Extension of genl attribute validation policies {{{1 + * {{{2 + */ + +/** + * nla_is_required - return true if this attribute is required + * @nla: netlink attribute + */ +static inline int nla_is_required(const struct nlattr *nla) +{ + return nla->nla_type & GENLA_F_REQUIRED; +} + +/** + * nla_is_mandatory - return true if understanding this attribute is mandatory + * @nla: netlink attribute + * Note: REQUIRED attributes are implicitly MANDATORY as well + */ +static inline int nla_is_mandatory(const struct nlattr *nla) +{ + return nla->nla_type & (GENLA_F_MANDATORY | GENLA_F_REQUIRED); +} + +/* Functionality to be integrated into nla_parse(), and validate_nla(), + * respectively. + * + * Enforcing the "mandatory" bit is done here, + * by rejecting unknown mandatory attributes. + * + * Part of enforcing the "required" flag would mean to embed it into + * nla_policy.type, and extending validate_nla(), which currently does + * BUG_ON(pt->type > NLA_TYPE_MAX); we have to work on existing kernels, + * so we cannot do that. Thats why enforcing "required" is done in the + * generated assignment functions below. */ +static int nla_check_unknown(int maxtype, struct nlattr *head, int len) +{ + struct nlattr *nla; + int rem; + nla_for_each_attr(nla, head, len, rem) { + __u16 type = nla_type(nla); + if (type > maxtype && nla_is_mandatory(nla)) + return -EOPNOTSUPP; + } + return 0; +} + +/* + * Magic: declare tla policy {{{1 + * Magic: declare nested policies + * {{{2 + */ +#undef GENL_mc_group +#define GENL_mc_group(group) + +#undef GENL_notification +#define GENL_notification(op_name, op_num, mcast_group, tla_list) + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ + [tag_name] = { .type = NLA_NESTED }, + +static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = { +#include GENL_MAGIC_INCLUDE_FILE +}; + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ +static struct nla_policy s_name ## _nl_policy[] __read_mostly = \ +{ s_fields }; + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, _type, __get, __put) \ + [__nla_type(attr_nr)] = { .type = nla_type }, + +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \ + __get, __put) \ + [__nla_type(attr_nr)] = { .type = nla_type, \ + .len = maxlen - (nla_type == NLA_NUL_STRING) }, + +#include GENL_MAGIC_INCLUDE_FILE + +#ifndef __KERNEL__ +#ifndef pr_info +#define pr_info(args...) fprintf(stderr, args); +#endif +#endif + +#if 1 +static void dprint_field(const char *dir, int nla_type, + const char *name, void *valp) +{ + __u64 val = valp ? *(__u32 *)valp : 1; + switch (nla_type) { + case NLA_U8: val = (__u8)val; + case NLA_U16: val = (__u16)val; + case NLA_U32: val = (__u32)val; + pr_info("%s attr %s: %d 0x%08x\n", dir, + name, (int)val, (unsigned)val); + break; + case NLA_U64: + val = *(__u64*)valp; + pr_info("%s attr %s: %lld 0x%08llx\n", dir, + name, (long long)val, (unsigned long long)val); + break; + case NLA_FLAG: + if (val) + pr_info("%s attr %s: set\n", dir, name); + break; + } +} + +static void dprint_array(const char *dir, int nla_type, + const char *name, const char *val, unsigned len) +{ + switch (nla_type) { + case NLA_NUL_STRING: + if (len && val[len-1] == '\0') + len--; + pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val); + break; + default: + /* we can always show 4 byte, + * thats what nlattr are aligned to. */ + pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n", + dir, name, len, val[0], val[1], val[2], val[3]); + } +} + +#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b); + +/* Name is a member field name of the struct s. + * If s is NULL (only parsing, no copy requested in *_from_attrs()), + * nla is supposed to point to the attribute containing the information + * corresponding to that struct member. */ +#define DPRINT_FIELD(dir, nla_type, name, s, nla) \ + do { \ + if (s) \ + dprint_field(dir, nla_type, #name, &s->name); \ + else if (nla) \ + dprint_field(dir, nla_type, #name, \ + (nla_type == NLA_FLAG) ? NULL \ + : nla_data(nla)); \ + } while (0) + +#define DPRINT_ARRAY(dir, nla_type, name, s, nla) \ + do { \ + if (s) \ + dprint_array(dir, nla_type, #name, \ + s->name, s->name ## _len); \ + else if (nla) \ + dprint_array(dir, nla_type, #name, \ + nla_data(nla), nla_len(nla)); \ + } while (0) +#else +#define DPRINT_TLA(a, op, b) do {} while (0) +#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0) +#define DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0) +#endif + +/* + * Magic: provide conversion functions {{{1 + * populate struct from attribute table: + * {{{2 + */ + +/* processing of generic netlink messages is serialized. + * use one static buffer for parsing of nested attributes */ +static struct nlattr *nested_attr_tb[128]; + +#ifndef BUILD_BUG_ON +/* Force a compilation error if condition is true */ +#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition)) +/* Force a compilation error if condition is true, but also produce a + result (of value 0 and type size_t), so the expression can be used + e.g. in a structure initializer (or where-ever else comma expressions + aren't permitted). */ +#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) +#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) +#endif + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ + /* static, potentially unused */ \ +int s_name ## _from_attrs(struct s_name *s, struct nlattr *tb[]) \ +{ \ + const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1; \ + struct nlattr *tla = tb[tag_number]; \ + struct nlattr **ntb = nested_attr_tb; \ + struct nlattr *nla; \ + int err; \ + BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb)); \ + if (!tla) \ + return -ENOMSG; \ + DPRINT_TLA(#s_name, "<=-", #tag_name); \ + err = nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \ + if (err) \ + return err; \ + err = nla_check_unknown(maxtype, nla_data(tla), nla_len(tla)); \ + if (err) \ + return err; \ + \ + s_fields \ + return 0; \ +} + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ + nla = ntb[__nla_type(attr_nr)]; \ + if (nla) { \ + if (s) \ + s->name = __get(nla); \ + DPRINT_FIELD("<<", nla_type, name, s, nla); \ + } else if ((attr_flag) & GENLA_F_REQUIRED) { \ + pr_info("<< missing attr: %s\n", #name); \ + return -ENOMSG; \ + } + +/* validate_nla() already checked nla_len <= maxlen appropriately. */ +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ + nla = ntb[__nla_type(attr_nr)]; \ + if (nla) { \ + if (s) \ + s->name ## _len = \ + __get(s->name, nla, maxlen); \ + DPRINT_ARRAY("<<", nla_type, name, s, nla); \ + } else if ((attr_flag) & GENLA_F_REQUIRED) { \ + pr_info("<< missing attr: %s\n", #name); \ + return -ENOMSG; \ + } \ + +#include GENL_MAGIC_INCLUDE_FILE + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) + +/* + * Magic: define op number to op name mapping {{{1 + * {{{2 + */ +const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd) +{ + switch (cmd) { +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) \ + case op_num: return #op_name; +#include GENL_MAGIC_INCLUDE_FILE + default: + return "unknown"; + } +} + +#ifdef __KERNEL__ +#include <linux/stringify.h> +/* + * Magic: define genl_ops {{{1 + * {{{2 + */ + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) \ +{ \ + handler \ + .cmd = op_name, \ + .policy = CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy), \ +}, + +#define ZZZ_genl_ops CONCAT_(GENL_MAGIC_FAMILY, _genl_ops) +static struct genl_ops ZZZ_genl_ops[] __read_mostly = { +#include GENL_MAGIC_INCLUDE_FILE +}; + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) + +/* + * Define the genl_family, multicast groups, {{{1 + * and provide register/unregister functions. + * {{{2 + */ +#define ZZZ_genl_family CONCAT_(GENL_MAGIC_FAMILY, _genl_family) +static struct genl_family ZZZ_genl_family __read_mostly = { + .id = GENL_ID_GENERATE, + .name = __stringify(GENL_MAGIC_FAMILY), + .version = GENL_MAGIC_VERSION, +#ifdef GENL_MAGIC_FAMILY_HDRSZ + .hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ), +#endif + .maxattr = ARRAY_SIZE(drbd_tla_nl_policy)-1, +}; + +/* + * Magic: define multicast groups + * Magic: define multicast group registration helper + */ +#undef GENL_mc_group +#define GENL_mc_group(group) \ +static struct genl_multicast_group \ +CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group) __read_mostly = { \ + .name = #group, \ +}; \ +static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \ + struct sk_buff *skb, gfp_t flags) \ +{ \ + unsigned int group_id = \ + CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id; \ + if (!group_id) \ + return -EINVAL; \ + return genlmsg_multicast(skb, 0, group_id, flags); \ +} + +#include GENL_MAGIC_INCLUDE_FILE + +int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void) +{ + int err = genl_register_family_with_ops(&ZZZ_genl_family, + ZZZ_genl_ops, ARRAY_SIZE(ZZZ_genl_ops)); + if (err) + return err; +#undef GENL_mc_group +#define GENL_mc_group(group) \ + err = genl_register_mc_group(&ZZZ_genl_family, \ + &CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group)); \ + if (err) \ + goto fail; \ + else \ + pr_info("%s: mcg %s: %u\n", #group, \ + __stringify(GENL_MAGIC_FAMILY), \ + CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id); + +#include GENL_MAGIC_INCLUDE_FILE + +#undef GENL_mc_group +#define GENL_mc_group(group) + return 0; +fail: + genl_unregister_family(&ZZZ_genl_family); + return err; +} + +void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void) +{ + genl_unregister_family(&ZZZ_genl_family); +} + +/* + * Magic: provide conversion functions {{{1 + * populate skb from struct. + * {{{2 + */ + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ +static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \ + const bool exclude_sensitive) \ +{ \ + struct nlattr *tla = nla_nest_start(skb, tag_number); \ + if (!tla) \ + goto nla_put_failure; \ + DPRINT_TLA(#s_name, "-=>", #tag_name); \ + s_fields \ + nla_nest_end(skb, tla); \ + return 0; \ + \ +nla_put_failure: \ + if (tla) \ + nla_nest_cancel(skb, tla); \ + return -EMSGSIZE; \ +} \ +static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \ + struct s_name *s) \ +{ \ + return s_name ## _to_skb(skb, s, 0); \ +} \ +static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \ + struct s_name *s) \ +{ \ + return s_name ## _to_skb(skb, s, 1); \ +} + + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ + if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \ + DPRINT_FIELD(">>", nla_type, name, s, NULL); \ + __put(skb, attr_nr, s->name); \ + } + +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ + if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \ + DPRINT_ARRAY(">>",nla_type, name, s, NULL); \ + __put(skb, attr_nr, min_t(int, maxlen, \ + s->name ## _len + (nla_type == NLA_NUL_STRING)),\ + s->name); \ + } + +#include GENL_MAGIC_INCLUDE_FILE + +#endif /* __KERNEL__ */ + +/* }}}1 */ +#endif /* GENL_MAGIC_FUNC_H */ +/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */ diff --git a/include/linux/genl_magic_struct.h b/include/linux/genl_magic_struct.h new file mode 100644 index 00000000000..745ebfd6c7e --- /dev/null +++ b/include/linux/genl_magic_struct.h @@ -0,0 +1,260 @@ +#ifndef GENL_MAGIC_STRUCT_H +#define GENL_MAGIC_STRUCT_H + +#ifndef GENL_MAGIC_FAMILY +# error "you need to define GENL_MAGIC_FAMILY before inclusion" +#endif + +#ifndef GENL_MAGIC_VERSION +# error "you need to define GENL_MAGIC_VERSION before inclusion" +#endif + +#ifndef GENL_MAGIC_INCLUDE_FILE +# error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion" +#endif + +#include <linux/genetlink.h> +#include <linux/types.h> + +#define CONCAT__(a,b) a ## b +#define CONCAT_(a,b) CONCAT__(a,b) + +extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void); +extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void); + +/* + * Extension of genl attribute validation policies {{{2 + */ + +/** + * GENLA_F_FLAGS - policy type flags to ease compatible ABI evolvement + * + * @GENLA_F_REQUIRED: attribute has to be present, or message is considered invalid. + * Adding new REQUIRED attributes breaks ABI compatibility, so don't do that. + * + * @GENLA_F_MANDATORY: if present, receiver _must_ understand it. + * Without this, unknown attributes (> maxtype) are _silently_ ignored + * by validate_nla(). + * + * To be used for API extensions, so older kernel can reject requests for not + * yet implemented features, if newer userland tries to use them even though + * the genl_family version clearly indicates they are not available. + * + * @GENLA_F_MAY_IGNORE: To clearly document the fact, for good measure. + * To be used for API extensions for things that have sane defaults, + * so newer userland can still talk to older kernel, knowing it will + * silently ignore these attributes if not yet known. + * + * NOTE: These flags overload + * NLA_F_NESTED (1 << 15) + * NLA_F_NET_BYTEORDER (1 << 14) + * from linux/netlink.h, which are not useful for validate_nla(): + * NET_BYTEORDER is not used anywhere, and NESTED would be specified by setting + * .type = NLA_NESTED in the appropriate policy. + * + * See also: nla_type() + */ +enum { + GENLA_F_MAY_IGNORE = 0, + GENLA_F_MANDATORY = 1 << 14, + GENLA_F_REQUIRED = 1 << 15, + + /* This will not be present in the __u16 .nla_type, but can be + * triggered on in <struct>_to_skb, to exclude "sensitive" + * information from broadcasts, or on unpriviledged get requests. + * This is useful because genetlink multicast groups can be listened in + * on by anyone. */ + GENLA_F_SENSITIVE = 1 << 16, +}; + +#define __nla_type(x) ((__u16)((__u16)(x) & (__u16)NLA_TYPE_MASK)) + +/* }}}1 + * MAGIC + * multi-include macro expansion magic starts here + */ + +/* MAGIC helpers {{{2 */ + +/* possible field types */ +#define __flg_field(attr_nr, attr_flag, name) \ + __field(attr_nr, attr_flag, name, NLA_FLAG, char, \ + nla_get_flag, __nla_put_flag) +#define __u8_field(attr_nr, attr_flag, name) \ + __field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \ + nla_get_u8, NLA_PUT_U8) +#define __u16_field(attr_nr, attr_flag, name) \ + __field(attr_nr, attr_flag, name, NLA_U16, __u16, \ + nla_get_u16, NLA_PUT_U16) +#define __u32_field(attr_nr, attr_flag, name) \ + __field(attr_nr, attr_flag, name, NLA_U32, __u32, \ + nla_get_u32, NLA_PUT_U32) +#define __u64_field(attr_nr, attr_flag, name) \ + __field(attr_nr, attr_flag, name, NLA_U64, __u64, \ + nla_get_u64, NLA_PUT_U64) +#define __str_field(attr_nr, attr_flag, name, maxlen) \ + __array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \ + nla_strlcpy, NLA_PUT) +#define __bin_field(attr_nr, attr_flag, name, maxlen) \ + __array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \ + nla_memcpy, NLA_PUT) + +#define __nla_put_flag(skb, attrtype, value) \ + do { \ + if (value) \ + NLA_PUT_FLAG(skb, attrtype); \ + } while (0) + +#define GENL_op_init(args...) args +#define GENL_doit(handler) \ + .doit = handler, \ + .flags = GENL_ADMIN_PERM, +#define GENL_dumpit(handler) \ + .dumpit = handler, \ + .flags = GENL_ADMIN_PERM, + +/* }}}1 + * Magic: define the enum symbols for genl_ops + * Magic: define the enum symbols for top level attributes + * Magic: define the enum symbols for nested attributes + * {{{2 + */ + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) + +#undef GENL_mc_group +#define GENL_mc_group(group) + +#undef GENL_notification +#define GENL_notification(op_name, op_num, mcast_group, tla_list) \ + op_name = op_num, + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, tla_list) \ + op_name = op_num, + +enum { +#include GENL_MAGIC_INCLUDE_FILE +}; + +#undef GENL_notification +#define GENL_notification(op_name, op_num, mcast_group, tla_list) + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, attr_list) + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ + tag_name = tag_number, + +enum { +#include GENL_MAGIC_INCLUDE_FILE +}; + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ +enum { \ + s_fields \ +}; + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ + T_ ## name = (__u16)(attr_nr | attr_flag), + +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ + T_ ## name = (__u16)(attr_nr | attr_flag), + +#include GENL_MAGIC_INCLUDE_FILE + +/* }}}1 + * Magic: compile time assert unique numbers for operations + * Magic: -"- unique numbers for top level attributes + * Magic: -"- unique numbers for nested attributes + * {{{2 + */ + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, attr_list) \ + case op_name: + +#undef GENL_notification +#define GENL_notification(op_name, op_num, mcast_group, tla_list) \ + case op_name: + +static inline void ct_assert_unique_operations(void) +{ + switch (0) { +#include GENL_MAGIC_INCLUDE_FILE + ; + } +} + +#undef GENL_op +#define GENL_op(op_name, op_num, handler, attr_list) + +#undef GENL_notification +#define GENL_notification(op_name, op_num, mcast_group, tla_list) + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ + case tag_number: + +static inline void ct_assert_unique_top_level_attributes(void) +{ + switch (0) { +#include GENL_MAGIC_INCLUDE_FILE + ; + } +} + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ +static inline void ct_assert_unique_ ## s_name ## _attributes(void) \ +{ \ + switch (0) { \ + s_fields \ + ; \ + } \ +} + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ + case attr_nr: + +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ + case attr_nr: + +#include GENL_MAGIC_INCLUDE_FILE + +/* }}}1 + * Magic: declare structs + * struct <name> { + * fields + * }; + * {{{2 + */ + +#undef GENL_struct +#define GENL_struct(tag_name, tag_number, s_name, s_fields) \ +struct s_name { s_fields }; + +#undef __field +#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ + type name; + +#undef __array +#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ + type name[maxlen]; \ + __u32 name ## _len; + +#include GENL_MAGIC_INCLUDE_FILE + +/* }}}1 */ +#endif /* GENL_MAGIC_STRUCT_H */ +/* vim: set foldmethod=marker nofoldenable : */ |