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Message-Id: <20230603052547.631384-3-kuba@kernel.org>
Date: Fri, 2 Jun 2023 22:25:45 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org,
edumazet@...gle.com,
pabeni@...hat.com,
Jakub Kicinski <kuba@...nel.org>
Subject: [PATCH net-next 2/4] tools: ynl: user space helpers
Add "fixed" part of the user space Netlink Spec-based library.
This will get linked with the protocol implementations to form
a full API.
Signed-off-by: Jakub Kicinski <kuba@...nel.org>
---
.../userspace-api/netlink/intro-specs.rst | 79 ++
tools/net/ynl/Makefile | 19 +
tools/net/ynl/generated/Makefile | 45 +
tools/net/ynl/lib/Makefile | 28 +
tools/net/ynl/lib/ynl.c | 901 ++++++++++++++++++
tools/net/ynl/lib/ynl.h | 229 +++++
tools/net/ynl/ynl-regen.sh | 2 +-
7 files changed, 1302 insertions(+), 1 deletion(-)
create mode 100644 tools/net/ynl/Makefile
create mode 100644 tools/net/ynl/generated/Makefile
create mode 100644 tools/net/ynl/lib/Makefile
create mode 100644 tools/net/ynl/lib/ynl.c
create mode 100644 tools/net/ynl/lib/ynl.h
diff --git a/Documentation/userspace-api/netlink/intro-specs.rst b/Documentation/userspace-api/netlink/intro-specs.rst
index a3b847eafff7..bada89699455 100644
--- a/Documentation/userspace-api/netlink/intro-specs.rst
+++ b/Documentation/userspace-api/netlink/intro-specs.rst
@@ -78,3 +78,82 @@ to see other examples.
The code generation itself is performed by ``tools/net/ynl/ynl-gen-c.py``
but it takes a few arguments so calling it directly for each file
quickly becomes tedious.
+
+YNL lib
+=======
+
+``tools/net/ynl/lib/`` contains an implementation of a C library
+(based on libmnl) which integrates with code generated by
+``tools/net/ynl/ynl-gen-c.py`` to create easy to use netlink wrappers.
+
+YNL basics
+----------
+
+The YNL library consists of two parts - the generic code (functions
+prefix by ``ynl_``) and per-family auto-generated code (prefixed
+with the name of the family).
+
+To create a YNL socket call ynl_sock_create() passing the family
+struct (family structs are exported by the auto-generated code).
+ynl_sock_destroy() closes the socket.
+
+YNL requests
+------------
+
+Steps for issuing YNL requests are best explained on an example.
+All the functions and types in this example come from the auto-generated
+code (for the netdev family in this case):
+
+.. code-block:: c
+
+ // 0. Request and response pointers
+ struct netdev_dev_get_req *req;
+ struct netdev_dev_get_rsp *d;
+
+ // 1. Allocate a request
+ req = netdev_dev_get_req_alloc();
+ // 2. Set request parameters (as needed)
+ netdev_dev_get_req_set_ifindex(req, ifindex);
+
+ // 3. Issues the request
+ d = netdev_dev_get(ys, req);
+ // 4. Free the request arguments
+ netdev_dev_get_req_free(req);
+ // 5. Error check (the return value from step 3)
+ if (!d) {
+ // 6. Print the YNL-generated error
+ fprintf(stderr, "YNL: %s\n", ys->err.msg);
+ return -1;
+ }
+
+ // ... do stuff with the response @d
+
+ // 7. Free response
+ netdev_dev_get_rsp_free(d);
+
+YNL dumps
+---------
+
+Performing dumps follows similar pattern as requests.
+Dumps return a list of objects terminated by a special marker,
+or NULL on error. Use ``ynl_dump_foreach()`` to iterate over
+the result.
+
+YNL notifications
+-----------------
+
+YNL lib supports using the same socket for notifications and
+requests. In case notifications arrive during processing of a request
+they are queued internally and can be retrieved at a later time.
+
+To subscribed to notifications use ``ynl_subscribe()``.
+The notifications have to be read out from the socket,
+``ynl_socket_get_fd()`` returns the underlying socket fd which can
+be plugged into appropriate asynchronous IO API like ``poll``,
+or ``select``.
+
+Notifications can be retrieved using ``ynl_ntf_dequeue()`` and have
+to be freed using ``ynl_ntf_free()``. Since we don't know the notification
+type upfront the notifications are returned as ``struct ynl_ntf_base_type *``
+and user is expected to cast them to the appropriate full type based
+on the ``cmd`` member.
diff --git a/tools/net/ynl/Makefile b/tools/net/ynl/Makefile
new file mode 100644
index 000000000000..d664b36deb5b
--- /dev/null
+++ b/tools/net/ynl/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+
+SUBDIRS = lib generated samples
+
+all: $(SUBDIRS)
+
+$(SUBDIRS):
+ @if [ -f "$@...kefile" ] ; then \
+ $(MAKE) -C $@ ; \
+ fi
+
+clean hardclean:
+ @for dir in $(SUBDIRS) ; do \
+ if [ -f "$$dir/Makefile" ] ; then \
+ $(MAKE) -C $$dir $@; \
+ fi \
+ done
+
+.PHONY: clean all $(SUBDIRS)
diff --git a/tools/net/ynl/generated/Makefile b/tools/net/ynl/generated/Makefile
new file mode 100644
index 000000000000..22f566eb095c
--- /dev/null
+++ b/tools/net/ynl/generated/Makefile
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CC=gcc
+CFLAGS=-std=gnu99 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
+ -I../lib/
+ifeq ("$(DEBUG)","1")
+ CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
+endif
+
+TOOL:=../ynl-gen-c.py
+
+GENS:=
+SRCS=$(patsubst %,%-user.c,${GENS})
+HDRS=$(patsubst %,%-user.h,${GENS})
+OBJS=$(patsubst %,%-user.o,${GENS})
+
+all: protos.a $(HDRS) $(SRCS) $(KHDRS) $(KSRCS) $(UAPI) regen
+
+protos.a: $(OBJS)
+ @echo -e "\tAR $@"
+ @ar rcs $@ $(OBJS)
+
+%-user.h: ../../../../Documentation/netlink/specs/%.yaml $(TOOL)
+ @echo -e "\tGEN $@"
+ @$(TOOL) --mode user --header --spec $< > $@
+
+%-user.c: ../../../../Documentation/netlink/specs/%.yaml $(TOOL)
+ @echo -e "\tGEN $@"
+ @$(TOOL) --mode user --source --spec $< > $@
+
+%-user.o: %-user.c %-user.h
+ @echo -e "\tCC $@"
+ @$(COMPILE.c) -c -o $@ $<
+
+clean:
+ rm -f *.o
+
+hardclean: clean
+ rm -f *.c *.h *.a
+
+regen:
+ @../ynl-regen.sh
+
+.PHONY: all clean hardclean regen
+.DEFAULT_GOAL: all
diff --git a/tools/net/ynl/lib/Makefile b/tools/net/ynl/lib/Makefile
new file mode 100644
index 000000000000..943021cc8eb3
--- /dev/null
+++ b/tools/net/ynl/lib/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CC=gcc
+CFLAGS=-std=gnu99 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow
+ifeq ("$(DEBUG)","1")
+ CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
+endif
+
+SRCS=$(wildcard *.c)
+OBJS=$(patsubst %.c,%.o,${SRCS})
+
+include $(wildcard *.d)
+
+all: ynl.a
+
+ynl.a: $(OBJS)
+ ar rcs $@ $(OBJS)
+clean:
+ rm -f *.o *.d *~
+
+hardclean: clean
+ rm -f *.a
+
+%.o: %.c
+ $(COMPILE.c) -MMD -c -o $@ $<
+
+.PHONY: all clean
+.DEFAULT_GOAL=all
diff --git a/tools/net/ynl/lib/ynl.c b/tools/net/ynl/lib/ynl.c
new file mode 100644
index 000000000000..514e0d69e731
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.c
@@ -0,0 +1,901 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#include <errno.h>
+#include <poll.h>
+#include <string.h>
+#include <stdlib.h>
+#include <linux/types.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+
+#include "ynl.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(*arr))
+
+#define __yerr_msg(yse, _msg...) \
+ ({ \
+ struct ynl_error *_yse = (yse); \
+ \
+ if (_yse) { \
+ snprintf(_yse->msg, sizeof(_yse->msg) - 1, _msg); \
+ _yse->msg[sizeof(_yse->msg) - 1] = 0; \
+ } \
+ })
+
+#define __yerr_code(yse, _code...) \
+ ({ \
+ struct ynl_error *_yse = (yse); \
+ \
+ if (_yse) { \
+ _yse->code = _code; \
+ } \
+ })
+
+#define __yerr(yse, _code, _msg...) \
+ ({ \
+ __yerr_msg(yse, _msg); \
+ __yerr_code(yse, _code); \
+ })
+
+#define __perr(yse, _msg) __yerr(yse, errno, _msg)
+
+#define yerr_msg(_ys, _msg...) __yerr_msg(&(_ys)->err, _msg)
+#define yerr(_ys, _code, _msg...) __yerr(&(_ys)->err, _code, _msg)
+#define perr(_ys, _msg) __yerr(&(_ys)->err, errno, _msg)
+
+/* -- Netlink boiler plate */
+static int
+ynl_err_walk_report_one(struct ynl_policy_nest *policy, unsigned int type,
+ char *str, int str_sz, int *n)
+{
+ if (!policy) {
+ if (*n < str_sz)
+ *n += snprintf(str, str_sz, "!policy");
+ return 1;
+ }
+
+ if (type > policy->max_attr) {
+ if (*n < str_sz)
+ *n += snprintf(str, str_sz, "!oob");
+ return 1;
+ }
+
+ if (!policy->table[type].name) {
+ if (*n < str_sz)
+ *n += snprintf(str, str_sz, "!name");
+ return 1;
+ }
+
+ if (*n < str_sz)
+ *n += snprintf(str, str_sz - *n,
+ ".%s", policy->table[type].name);
+ return 0;
+}
+
+static int
+ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off,
+ struct ynl_policy_nest *policy, char *str, int str_sz,
+ struct ynl_policy_nest **nest_pol)
+{
+ unsigned int astart_off, aend_off;
+ const struct nlattr *attr;
+ unsigned int data_len;
+ unsigned int type;
+ bool found = false;
+ int n = 0;
+
+ if (!policy) {
+ if (n < str_sz)
+ n += snprintf(str, str_sz, "!policy");
+ return n;
+ }
+
+ data_len = end - start;
+
+ mnl_attr_for_each_payload(start, data_len) {
+ astart_off = (char *)attr - (char *)start;
+ aend_off = astart_off + mnl_attr_get_payload_len(attr);
+ if (aend_off <= off)
+ continue;
+
+ found = true;
+ break;
+ }
+ if (!found)
+ return 0;
+
+ off -= astart_off;
+
+ type = mnl_attr_get_type(attr);
+
+ if (ynl_err_walk_report_one(policy, type, str, str_sz, &n))
+ return n;
+
+ if (!off) {
+ if (nest_pol)
+ *nest_pol = policy->table[type].nest;
+ return n;
+ }
+
+ if (!policy->table[type].nest) {
+ if (n < str_sz)
+ n += snprintf(str, str_sz, "!nest");
+ return n;
+ }
+
+ off -= sizeof(struct nlattr);
+ start = mnl_attr_get_payload(attr);
+ end = start + mnl_attr_get_payload_len(attr);
+
+ return n + ynl_err_walk(ys, start, end, off, policy->table[type].nest,
+ &str[n], str_sz - n, nest_pol);
+}
+
+#define NLMSGERR_ATTR_MISS_TYPE (NLMSGERR_ATTR_POLICY + 1)
+#define NLMSGERR_ATTR_MISS_NEST (NLMSGERR_ATTR_POLICY + 2)
+#define NLMSGERR_ATTR_MAX (NLMSGERR_ATTR_MAX + 2)
+
+static int
+ynl_ext_ack_check(struct ynl_sock *ys, const struct nlmsghdr *nlh,
+ unsigned int hlen)
+{
+ const struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
+ char miss_attr[sizeof(ys->err.msg)];
+ char bad_attr[sizeof(ys->err.msg)];
+ const struct nlattr *attr;
+ const char *str = NULL;
+
+ if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
+ return MNL_CB_OK;
+
+ mnl_attr_for_each(attr, nlh, hlen) {
+ unsigned int len, type;
+
+ len = mnl_attr_get_payload_len(attr);
+ type = mnl_attr_get_type(attr);
+
+ if (type > NLMSGERR_ATTR_MAX)
+ continue;
+
+ tb[type] = attr;
+
+ switch (type) {
+ case NLMSGERR_ATTR_OFFS:
+ case NLMSGERR_ATTR_MISS_TYPE:
+ case NLMSGERR_ATTR_MISS_NEST:
+ if (len != sizeof(__u32))
+ return MNL_CB_ERROR;
+ break;
+ case NLMSGERR_ATTR_MSG:
+ str = mnl_attr_get_payload(attr);
+ if (str[len - 1])
+ return MNL_CB_ERROR;
+ break;
+ default:
+ break;
+ }
+ }
+
+ bad_attr[0] = '\0';
+ miss_attr[0] = '\0';
+
+ if (tb[NLMSGERR_ATTR_OFFS]) {
+ unsigned int n, off;
+ void *start, *end;
+
+ ys->err.attr_offs = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
+
+ n = snprintf(bad_attr, sizeof(bad_attr), "%sbad attribute: ",
+ str ? " (" : "");
+
+ start = mnl_nlmsg_get_payload_offset(ys->nlh,
+ sizeof(struct genlmsghdr));
+ end = mnl_nlmsg_get_payload_tail(ys->nlh);
+
+ off = ys->err.attr_offs;
+ off -= sizeof(struct nlmsghdr);
+ off -= sizeof(struct genlmsghdr);
+
+ n += ynl_err_walk(ys, start, end, off, ys->req_policy,
+ &bad_attr[n], sizeof(bad_attr) - n, NULL);
+
+ if (n >= sizeof(bad_attr))
+ n = sizeof(bad_attr) - 1;
+ bad_attr[n] = '\0';
+ }
+ if (tb[NLMSGERR_ATTR_MISS_TYPE]) {
+ struct ynl_policy_nest *nest_pol = NULL;
+ unsigned int n, off, type;
+ void *start, *end;
+ int n2;
+
+ type = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_TYPE]);
+
+ n = snprintf(miss_attr, sizeof(miss_attr), "%smissing attribute: ",
+ bad_attr[0] ? ", " : (str ? " (" : ""));
+
+ start = mnl_nlmsg_get_payload_offset(ys->nlh,
+ sizeof(struct genlmsghdr));
+ end = mnl_nlmsg_get_payload_tail(ys->nlh);
+
+ nest_pol = ys->req_policy;
+ if (tb[NLMSGERR_ATTR_MISS_NEST]) {
+ off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_NEST]);
+ off -= sizeof(struct nlmsghdr);
+ off -= sizeof(struct genlmsghdr);
+
+ n += ynl_err_walk(ys, start, end, off, ys->req_policy,
+ &miss_attr[n], sizeof(miss_attr) - n,
+ &nest_pol);
+ }
+
+ n2 = 0;
+ ynl_err_walk_report_one(nest_pol, type, &miss_attr[n],
+ sizeof(miss_attr) - n, &n2);
+ n += n2;
+
+ if (n >= sizeof(miss_attr))
+ n = sizeof(miss_attr) - 1;
+ miss_attr[n] = '\0';
+ }
+
+ /* Implicitly depend on ys->err.code already set */
+ if (str)
+ yerr_msg(ys, "Kernel %s: '%s'%s%s%s",
+ ys->err.code ? "error" : "warning",
+ str, bad_attr, miss_attr,
+ bad_attr[0] || miss_attr[0] ? ")" : "");
+ else if (bad_attr[0] || miss_attr[0])
+ yerr_msg(ys, "Kernel %s: %s%s",
+ ys->err.code ? "error" : "warning",
+ bad_attr, miss_attr);
+
+ return MNL_CB_OK;
+}
+
+static int ynl_cb_error(const struct nlmsghdr *nlh, void *data)
+{
+ const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
+ struct ynl_parse_arg *yarg = data;
+ unsigned int hlen;
+ int code;
+
+ code = err->error >= 0 ? err->error : -err->error;
+ yarg->ys->err.code = code;
+ errno = code;
+
+ hlen = sizeof(*err);
+ if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
+ hlen += mnl_nlmsg_get_payload_len(&err->msg);
+
+ ynl_ext_ack_check(yarg->ys, nlh, hlen);
+
+ return code ? MNL_CB_ERROR : MNL_CB_STOP;
+}
+
+static int ynl_cb_done(const struct nlmsghdr *nlh, void *data)
+{
+ struct ynl_parse_arg *yarg = data;
+ int err;
+
+ err = *(int *)NLMSG_DATA(nlh);
+ if (err < 0) {
+ yarg->ys->err.code = -err;
+ errno = -err;
+
+ ynl_ext_ack_check(yarg->ys, nlh, sizeof(int));
+
+ return MNL_CB_ERROR;
+ }
+ return MNL_CB_STOP;
+}
+
+static int ynl_cb_noop(const struct nlmsghdr *nlh, void *data)
+{
+ return MNL_CB_OK;
+}
+
+mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE] = {
+ [NLMSG_NOOP] = ynl_cb_noop,
+ [NLMSG_ERROR] = ynl_cb_error,
+ [NLMSG_DONE] = ynl_cb_done,
+ [NLMSG_OVERRUN] = ynl_cb_noop,
+};
+
+/* Attribute validation */
+
+int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr)
+{
+ struct ynl_policy_attr *policy;
+ unsigned int type, len;
+ unsigned char *data;
+
+ data = mnl_attr_get_payload(attr);
+ len = mnl_attr_get_payload_len(attr);
+ type = mnl_attr_get_type(attr);
+ if (type > yarg->rsp_policy->max_attr) {
+ yerr(yarg->ys, YNL_ERROR_INTERNAL,
+ "Internal error, validating unknown attribute");
+ return -1;
+ }
+
+ policy = &yarg->rsp_policy->table[type];
+
+ switch (policy->type) {
+ case YNL_PT_REJECT:
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Rejected attribute (%s)", policy->name);
+ return -1;
+ case YNL_PT_IGNORE:
+ break;
+ case YNL_PT_U8:
+ if (len == sizeof(__u8))
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (u8 %s)", policy->name);
+ return -1;
+ case YNL_PT_U16:
+ if (len == sizeof(__u16))
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (u16 %s)", policy->name);
+ return -1;
+ case YNL_PT_U32:
+ if (len == sizeof(__u32))
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (u32 %s)", policy->name);
+ return -1;
+ case YNL_PT_U64:
+ if (len == sizeof(__u64))
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (u64 %s)", policy->name);
+ return -1;
+ case YNL_PT_FLAG:
+ /* Let flags grow into real attrs, why not.. */
+ break;
+ case YNL_PT_NEST:
+ if (!len || len >= sizeof(*attr))
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (nest %s)", policy->name);
+ return -1;
+ case YNL_PT_BINARY:
+ if (!policy->len || len == policy->len)
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (binary %s)", policy->name);
+ return -1;
+ case YNL_PT_NUL_STR:
+ if ((!policy->len || len <= policy->len) && !data[len - 1])
+ break;
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (string %s)", policy->name);
+ return -1;
+ default:
+ yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+ "Invalid attribute (unknown %s)", policy->name);
+ return -1;
+ }
+
+ return 0;
+}
+
+/* Generic code */
+
+static void ynl_err_reset(struct ynl_sock *ys)
+{
+ ys->err.code = 0;
+ ys->err.attr_offs = 0;
+ ys->err.msg[0] = 0;
+}
+
+struct nlmsghdr *ynl_msg_start(struct ynl_sock *ys, __u32 id, __u16 flags)
+{
+ struct nlmsghdr *nlh;
+
+ ynl_err_reset(ys);
+
+ nlh = ys->nlh = mnl_nlmsg_put_header(ys->tx_buf);
+ nlh->nlmsg_type = id;
+ nlh->nlmsg_flags = flags;
+ nlh->nlmsg_seq = ++ys->seq;
+
+ return nlh;
+}
+
+struct nlmsghdr *
+ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags,
+ __u8 cmd, __u8 version)
+{
+ struct genlmsghdr gehdr;
+ struct nlmsghdr *nlh;
+ void *data;
+
+ nlh = ynl_msg_start(ys, id, flags);
+
+ memset(&gehdr, 0, sizeof(gehdr));
+ gehdr.cmd = cmd;
+ gehdr.version = version;
+
+ data = mnl_nlmsg_put_extra_header(nlh, sizeof(gehdr));
+ memcpy(data, &gehdr, sizeof(gehdr));
+
+ return nlh;
+}
+
+void ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
+{
+ ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
+}
+
+void ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
+{
+ ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
+}
+
+struct nlmsghdr *
+ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)
+{
+ return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK, cmd, version);
+}
+
+struct nlmsghdr *
+ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)
+{
+ return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP,
+ cmd, version);
+}
+
+int ynl_recv_ack(struct ynl_sock *ys, int ret)
+{
+ if (!ret) {
+ yerr(ys, YNL_ERROR_EXPECT_ACK,
+ "Expecting an ACK but nothing received");
+ return -1;
+ }
+
+ ret = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE);
+ if (ret < 0) {
+ perr(ys, "Socket receive failed");
+ return ret;
+ }
+ return mnl_cb_run(ys->rx_buf, ret, ys->seq, ys->portid,
+ ynl_cb_null, ys);
+}
+
+int ynl_cb_null(const struct nlmsghdr *nlh, void *data)
+{
+ struct ynl_parse_arg *yarg = data;
+
+ yerr(yarg->ys, YNL_ERROR_UNEXPECT_MSG,
+ "Received a message when none were expected");
+
+ return MNL_CB_ERROR;
+}
+
+/* Init/fini and genetlink boiler plate */
+static int
+ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts)
+{
+ const struct nlattr *entry, *attr;
+ unsigned int i;
+
+ mnl_attr_for_each_nested(attr, mcasts)
+ ys->n_mcast_groups++;
+
+ if (!ys->n_mcast_groups)
+ return 0;
+
+ ys->mcast_groups = calloc(ys->n_mcast_groups,
+ sizeof(*ys->mcast_groups));
+ if (!ys->mcast_groups)
+ return MNL_CB_ERROR;
+
+ i = 0;
+ mnl_attr_for_each_nested(entry, mcasts) {
+ mnl_attr_for_each_nested(attr, entry) {
+ if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_ID)
+ ys->mcast_groups[i].id = mnl_attr_get_u32(attr);
+ if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_NAME) {
+ strncpy(ys->mcast_groups[i].name,
+ mnl_attr_get_str(attr),
+ GENL_NAMSIZ - 1);
+ ys->mcast_groups[i].name[GENL_NAMSIZ - 1] = 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int ynl_get_family_info_cb(const struct nlmsghdr *nlh, void *data)
+{
+ struct ynl_parse_arg *yarg = data;
+ struct ynl_sock *ys = yarg->ys;
+ const struct nlattr *attr;
+ bool found_id = true;
+
+ mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
+ if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GROUPS)
+ if (ynl_get_family_info_mcast(ys, attr))
+ return MNL_CB_ERROR;
+
+ if (mnl_attr_get_type(attr) != CTRL_ATTR_FAMILY_ID)
+ continue;
+
+ if (mnl_attr_get_payload_len(attr) != sizeof(__u16)) {
+ yerr(ys, YNL_ERROR_ATTR_INVALID, "Invalid family ID");
+ return MNL_CB_ERROR;
+ }
+
+ ys->family_id = mnl_attr_get_u16(attr);
+ found_id = true;
+ }
+
+ if (!found_id) {
+ yerr(ys, YNL_ERROR_ATTR_MISSING, "Family ID missing");
+ return MNL_CB_ERROR;
+ }
+ return MNL_CB_OK;
+}
+
+static int ynl_sock_read_family(struct ynl_sock *ys, const char *family_name)
+{
+ struct ynl_parse_arg yarg = { .ys = ys, };
+ struct nlmsghdr *nlh;
+ int err;
+
+ nlh = ynl_gemsg_start_req(ys, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, 1);
+ mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, family_name);
+
+ err = mnl_socket_sendto(ys->sock, nlh, nlh->nlmsg_len);
+ if (err < 0) {
+ perr(ys, "failed to request socket family info");
+ return err;
+ }
+
+ err = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE);
+ if (err <= 0) {
+ perr(ys, "failed to receive the socket family info");
+ return err;
+ }
+ err = mnl_cb_run2(ys->rx_buf, err, ys->seq, ys->portid,
+ ynl_get_family_info_cb, &yarg,
+ ynl_cb_array, ARRAY_SIZE(ynl_cb_array));
+ if (err < 0) {
+ free(ys->mcast_groups);
+ perr(ys, "failed to receive the socket family info - no such family?");
+ return err;
+ }
+
+ return ynl_recv_ack(ys, err);
+}
+
+struct ynl_sock *
+ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse)
+{
+ struct ynl_sock *ys;
+ int one = 1;
+
+ ys = malloc(sizeof(*ys) + 2 * MNL_SOCKET_BUFFER_SIZE);
+ if (!ys)
+ return NULL;
+ memset(ys, 0, sizeof(*ys));
+
+ ys->family = yf;
+ ys->tx_buf = &ys->raw_buf[0];
+ ys->rx_buf = &ys->raw_buf[MNL_SOCKET_BUFFER_SIZE];
+ ys->ntf_last_next = &ys->ntf_first;
+
+ ys->sock = mnl_socket_open(NETLINK_GENERIC);
+ if (!ys->sock) {
+ __perr(yse, "failed to create a netlink socket");
+ goto err_free_sock;
+ }
+
+ if (mnl_socket_setsockopt(ys->sock, NETLINK_CAP_ACK,
+ &one, sizeof(one))) {
+ __perr(yse, "failed to enable netlink ACK");
+ goto err_close_sock;
+ }
+ if (mnl_socket_setsockopt(ys->sock, NETLINK_EXT_ACK,
+ &one, sizeof(one))) {
+ __perr(yse, "failed to enable netlink ext ACK");
+ goto err_close_sock;
+ }
+
+ ys->seq = random();
+ ys->portid = mnl_socket_get_portid(ys->sock);
+
+ if (ynl_sock_read_family(ys, yf->name)) {
+ if (yse)
+ memcpy(yse, &ys->err, sizeof(*yse));
+ goto err_close_sock;
+ }
+
+ return ys;
+
+err_close_sock:
+ mnl_socket_close(ys->sock);
+err_free_sock:
+ free(ys);
+ return NULL;
+}
+
+void ynl_sock_destroy(struct ynl_sock *ys)
+{
+ struct ynl_ntf_base_type *ntf;
+
+ mnl_socket_close(ys->sock);
+ while ((ntf = ynl_ntf_dequeue(ys)))
+ ynl_ntf_free(ntf);
+ free(ys->mcast_groups);
+ free(ys);
+}
+
+/* YNL multicast handling */
+
+void ynl_ntf_free(struct ynl_ntf_base_type *ntf)
+{
+ ntf->free(ntf);
+}
+
+int ynl_subscribe(struct ynl_sock *ys, const char *grp_name)
+{
+ unsigned int i;
+ int err;
+
+ for (i = 0; i < ys->n_mcast_groups; i++)
+ if (!strcmp(ys->mcast_groups[i].name, grp_name))
+ break;
+ if (i == ys->n_mcast_groups) {
+ yerr(ys, ENOENT, "Multicast group '%s' not found", grp_name);
+ return -1;
+ }
+
+ err = mnl_socket_setsockopt(ys->sock, NETLINK_ADD_MEMBERSHIP,
+ &ys->mcast_groups[i].id,
+ sizeof(ys->mcast_groups[i].id));
+ if (err < 0) {
+ perr(ys, "Subscribing to multicast group failed");
+ return -1;
+ }
+
+ return 0;
+}
+
+int ynl_socket_get_fd(struct ynl_sock *ys)
+{
+ return mnl_socket_get_fd(ys->sock);
+}
+
+struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys)
+{
+ struct ynl_ntf_base_type *ntf;
+
+ if (!ynl_has_ntf(ys))
+ return NULL;
+
+ ntf = ys->ntf_first;
+ ys->ntf_first = ntf->next;
+ if (ys->ntf_last_next == &ntf->next)
+ ys->ntf_last_next = &ys->ntf_first;
+
+ return ntf;
+}
+
+static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)
+{
+ struct ynl_parse_arg yarg = { .ys = ys, };
+ const struct ynl_ntf_info *info;
+ struct ynl_ntf_base_type *rsp;
+ struct genlmsghdr *gehdr;
+ int ret;
+
+ gehdr = mnl_nlmsg_get_payload(nlh);
+ if (gehdr->cmd >= ys->family->ntf_info_size)
+ return MNL_CB_ERROR;
+ info = &ys->family->ntf_info[gehdr->cmd];
+ if (!info->cb)
+ return MNL_CB_ERROR;
+
+ rsp = calloc(1, info->alloc_sz);
+ rsp->free = info->free;
+ yarg.data = rsp->data;
+ yarg.rsp_policy = info->policy;
+
+ ret = info->cb(nlh, &yarg);
+ if (ret <= MNL_CB_STOP)
+ goto err_free;
+
+ rsp->family = nlh->nlmsg_type;
+ rsp->cmd = gehdr->cmd;
+
+ *ys->ntf_last_next = rsp;
+ ys->ntf_last_next = &rsp->next;
+
+ return MNL_CB_OK;
+
+err_free:
+ info->free(rsp);
+ return MNL_CB_ERROR;
+}
+
+static int ynl_ntf_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+ return ynl_ntf_parse((struct ynl_sock *)data, nlh);
+}
+
+int ynl_ntf_check(struct ynl_sock *ys)
+{
+ ssize_t len;
+ int err;
+
+ do {
+ /* libmnl doesn't let us pass flags to the recv to make
+ * it non-blocking so we need to poll() or peek() :|
+ */
+ struct pollfd pfd = { };
+
+ pfd.fd = mnl_socket_get_fd(ys->sock);
+ pfd.events = POLLIN;
+ err = poll(&pfd, 1, 1);
+ if (err < 1)
+ return err;
+
+ len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+ MNL_SOCKET_BUFFER_SIZE);
+ if (len < 0)
+ return len;
+
+ err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+ ynl_ntf_trampoline, ys,
+ ynl_cb_array, NLMSG_MIN_TYPE);
+ if (err < 0)
+ return err;
+ } while (err > 0);
+
+ return 0;
+}
+
+/* YNL specific helpers used by the auto-generated code */
+
+struct ynl_dump_list_type *YNL_LIST_END = (void *)(0xb4d123);
+
+void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd)
+{
+ yerr(ys, YNL_ERROR_UNKNOWN_NTF,
+ "Unknown notification message type '%d'", cmd);
+}
+
+int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg)
+{
+ yerr(yarg->ys, YNL_ERROR_INV_RESP, "Error parsing response: %s", msg);
+ return MNL_CB_ERROR;
+}
+
+static int
+ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd)
+{
+ struct genlmsghdr *gehdr;
+
+ if (mnl_nlmsg_get_payload_len(nlh) < sizeof(*gehdr)) {
+ yerr(ys, YNL_ERROR_INV_RESP,
+ "Kernel responded with truncated message");
+ return -1;
+ }
+
+ gehdr = mnl_nlmsg_get_payload(nlh);
+ if (gehdr->cmd != rsp_cmd)
+ return ynl_ntf_parse(ys, nlh);
+
+ return 0;
+}
+
+static int ynl_req_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+ struct ynl_req_state *yrs = data;
+ int ret;
+
+ ret = ynl_check_alien(yrs->yarg.ys, nlh, yrs->rsp_cmd);
+ if (ret)
+ return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK;
+
+ return yrs->cb(nlh, &yrs->yarg);
+}
+
+int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+ struct ynl_req_state *yrs)
+{
+ ssize_t len;
+ int err;
+
+ err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len);
+ if (err < 0)
+ return err;
+
+ do {
+ len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+ MNL_SOCKET_BUFFER_SIZE);
+ if (len < 0)
+ return len;
+
+ err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+ ynl_req_trampoline, yrs,
+ ynl_cb_array, NLMSG_MIN_TYPE);
+ if (err < 0)
+ return err;
+ } while (err > 0);
+
+ return 0;
+}
+
+static int ynl_dump_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+ struct ynl_dump_state *ds = data;
+ struct ynl_dump_list_type *obj;
+ struct ynl_parse_arg yarg = {};
+ int ret;
+
+ ret = ynl_check_alien(ds->ys, nlh, ds->rsp_cmd);
+ if (ret)
+ return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK;
+
+ obj = calloc(1, ds->alloc_sz);
+ if (!obj)
+ return MNL_CB_ERROR;
+
+ if (!ds->first)
+ ds->first = obj;
+ if (ds->last)
+ ds->last->next = obj;
+ ds->last = obj;
+
+ yarg.ys = ds->ys;
+ yarg.rsp_policy = ds->rsp_policy;
+ yarg.data = &obj->data;
+
+ return ds->cb(nlh, &yarg);
+}
+
+static void *ynl_dump_end(struct ynl_dump_state *ds)
+{
+ if (!ds->first)
+ return YNL_LIST_END;
+
+ ds->last->next = YNL_LIST_END;
+ return ds->first;
+}
+
+int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+ struct ynl_dump_state *yds)
+{
+ ssize_t len;
+ int err;
+
+ err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len);
+ if (err < 0)
+ return err;
+
+ do {
+ len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+ MNL_SOCKET_BUFFER_SIZE);
+ if (len < 0)
+ goto err_close_list;
+
+ err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+ ynl_dump_trampoline, yds,
+ ynl_cb_array, NLMSG_MIN_TYPE);
+ if (err < 0)
+ goto err_close_list;
+ } while (err > 0);
+
+ yds->first = ynl_dump_end(yds);
+ return 0;
+
+err_close_list:
+ yds->first = ynl_dump_end(yds);
+ return -1;
+}
diff --git a/tools/net/ynl/lib/ynl.h b/tools/net/ynl/lib/ynl.h
new file mode 100644
index 000000000000..ce2301d9558f
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.h
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#ifndef __YNL_C_H
+#define __YNL_C_H 1
+
+#include <stddef.h>
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+#include <linux/types.h>
+
+struct mnl_socket;
+struct nlmsghdr;
+
+/*
+ * User facing code
+ */
+
+struct ynl_ntf_base_type;
+struct ynl_ntf_info;
+struct ynl_sock;
+
+enum ynl_error_code {
+ YNL_ERROR_NONE = 0,
+ __YNL_ERRNO_END = 4096,
+ YNL_ERROR_INTERNAL,
+ YNL_ERROR_EXPECT_ACK,
+ YNL_ERROR_EXPECT_MSG,
+ YNL_ERROR_UNEXPECT_MSG,
+ YNL_ERROR_ATTR_MISSING,
+ YNL_ERROR_ATTR_INVALID,
+ YNL_ERROR_UNKNOWN_NTF,
+ YNL_ERROR_INV_RESP,
+};
+
+/**
+ * struct ynl_error - error encountered by YNL
+ * Users should interact with the err member of struct ynl_sock directly.
+ * The main exception to that rule is ynl_sock_create().
+ */
+struct ynl_error {
+ enum ynl_error_code code;
+ unsigned int attr_offs;
+ char msg[512];
+};
+
+/**
+ * struct ynl_family - YNL family info
+ * Family description generated by codegen.
+ */
+struct ynl_family {
+ const char *name;
+ const struct ynl_ntf_info *ntf_info;
+ unsigned int ntf_info_size;
+};
+
+/**
+ * struct ynl_sock - YNL wrapped netlink socket
+ * @err: YNL error descriptor, cleared on every request.
+ */
+struct ynl_sock {
+ struct ynl_error err;
+
+/* private: */
+ const struct ynl_family *family;
+ struct mnl_socket *sock;
+ __u32 seq;
+ __u32 portid;
+ __u16 family_id;
+
+ unsigned int n_mcast_groups;
+ struct {
+ unsigned int id;
+ char name[GENL_NAMSIZ];
+ } *mcast_groups;
+
+ struct ynl_ntf_base_type *ntf_first;
+ struct ynl_ntf_base_type **ntf_last_next;
+
+ struct nlmsghdr *nlh;
+ struct ynl_policy_nest *req_policy;
+ unsigned char *tx_buf;
+ unsigned char *rx_buf;
+ unsigned char raw_buf[];
+};
+
+struct ynl_sock *
+ynl_sock_create(const struct ynl_family *yf, struct ynl_error *e);
+void ynl_sock_destroy(struct ynl_sock *ys);
+
+#define ynl_dump_foreach(dump, iter) \
+ for (typeof(dump->obj) *iter = &dump->obj; \
+ !ynl_dump_obj_is_last(iter); \
+ iter = ynl_dump_obj_next(iter))
+
+int ynl_subscribe(struct ynl_sock *ys, const char *grp_name);
+int ynl_socket_get_fd(struct ynl_sock *ys);
+int ynl_ntf_check(struct ynl_sock *ys);
+
+/**
+ * ynl_has_ntf() - check if socket has *parsed* notifications
+ * Note that this does not take into account notifications sitting
+ * in netlink socket, just the notifications which have already been
+ * read and parsed (e.g. during a ynl_ntf_check() call).
+ */
+static inline bool ynl_has_ntf(struct ynl_sock *ys)
+{
+ return ys->ntf_last_next != &ys->ntf_first;
+}
+struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys);
+
+void ynl_ntf_free(struct ynl_ntf_base_type *ntf);
+
+/*
+ * YNL internals / low level stuff
+ */
+
+/* Generic mnl helper code */
+
+enum ynl_policy_type {
+ YNL_PT_REJECT = 1,
+ YNL_PT_IGNORE,
+ YNL_PT_NEST,
+ YNL_PT_FLAG,
+ YNL_PT_BINARY,
+ YNL_PT_U8,
+ YNL_PT_U16,
+ YNL_PT_U32,
+ YNL_PT_U64,
+ YNL_PT_NUL_STR,
+};
+
+struct ynl_policy_attr {
+ enum ynl_policy_type type;
+ unsigned int len;
+ const char *name;
+ struct ynl_policy_nest *nest;
+};
+
+struct ynl_policy_nest {
+ unsigned int max_attr;
+ struct ynl_policy_attr *table;
+};
+
+struct ynl_parse_arg {
+ struct ynl_sock *ys;
+ struct ynl_policy_nest *rsp_policy;
+ void *data;
+};
+
+struct ynl_dump_list_type {
+ struct ynl_dump_list_type *next;
+ unsigned char data[] __attribute__ ((aligned (8)));
+};
+extern struct ynl_dump_list_type *YNL_LIST_END;
+
+static inline bool ynl_dump_obj_is_last(void *obj)
+{
+ unsigned long uptr = (unsigned long)obj;
+
+ uptr -= offsetof(struct ynl_dump_list_type, data);
+ return uptr == (unsigned long)YNL_LIST_END;
+}
+
+static inline void *ynl_dump_obj_next(void *obj)
+{
+ unsigned long uptr = (unsigned long)obj;
+ struct ynl_dump_list_type *list;
+
+ uptr -= offsetof(struct ynl_dump_list_type, data);
+ list = (void *)uptr;
+ uptr = (unsigned long)list->next;
+ uptr += offsetof(struct ynl_dump_list_type, data);
+
+ return (void *)uptr;
+}
+
+struct ynl_ntf_base_type {
+ __u16 family;
+ __u8 cmd;
+ struct ynl_ntf_base_type *next;
+ void (*free)(struct ynl_ntf_base_type *ntf);
+ unsigned char data[] __attribute__ ((aligned (8)));
+};
+
+extern mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE];
+
+struct nlmsghdr *
+ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
+struct nlmsghdr *
+ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
+
+int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr);
+
+int ynl_recv_ack(struct ynl_sock *ys, int ret);
+int ynl_cb_null(const struct nlmsghdr *nlh, void *data);
+
+/* YNL specific helpers used by the auto-generated code */
+
+struct ynl_req_state {
+ struct ynl_parse_arg yarg;
+ mnl_cb_t cb;
+ __u32 rsp_cmd;
+};
+
+struct ynl_dump_state {
+ struct ynl_sock *ys;
+ struct ynl_policy_nest *rsp_policy;
+ void *first;
+ struct ynl_dump_list_type *last;
+ size_t alloc_sz;
+ mnl_cb_t cb;
+ __u32 rsp_cmd;
+};
+
+struct ynl_ntf_info {
+ struct ynl_policy_nest *policy;
+ mnl_cb_t cb;
+ size_t alloc_sz;
+ void (*free)(struct ynl_ntf_base_type *ntf);
+};
+
+int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+ struct ynl_req_state *yrs);
+int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+ struct ynl_dump_state *yds);
+
+void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd);
+int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg);
+
+#endif
diff --git a/tools/net/ynl/ynl-regen.sh b/tools/net/ynl/ynl-regen.sh
index 74f5de1c2399..2a4525e2aa17 100755
--- a/tools/net/ynl/ynl-regen.sh
+++ b/tools/net/ynl/ynl-regen.sh
@@ -14,7 +14,7 @@ done
KDIR=$(dirname $(dirname $(dirname $(dirname $(realpath $0)))))
-files=$(git grep --files-with-matches '^/\* YNL-GEN \(kernel\|uapi\)')
+files=$(git grep --files-with-matches '^/\* YNL-GEN \(kernel\|uapi\|user\)')
for f in $files; do
# params: 0 1 2 3
# $YAML YNL-GEN kernel $mode
--
2.40.1
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