Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 452 insertions, 0 deletions

diff --git a/kernel/bpf/mprog.c b/kernel/bpf/mprog.c
new file mode 100644
index 0000000000..1394168062
--- /dev/null
+++ b/kernel/bpf/mprog.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+
+#include <linux/bpf.h>
+#include <linux/bpf_mprog.h>
+
+static int bpf_mprog_link(struct bpf_tuple *tuple,
+			  u32 id_or_fd, u32 flags,
+			  enum bpf_prog_type type)
+{
+	struct bpf_link *link = ERR_PTR(-EINVAL);
+	bool id = flags & BPF_F_ID;
+
+	if (id)
+		link = bpf_link_by_id(id_or_fd);
+	else if (id_or_fd)
+		link = bpf_link_get_from_fd(id_or_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+	if (type && link->prog->type != type) {
+		bpf_link_put(link);
+		return -EINVAL;
+	}
+
+	tuple->link = link;
+	tuple->prog = link->prog;
+	return 0;
+}
+
+static int bpf_mprog_prog(struct bpf_tuple *tuple,
+			  u32 id_or_fd, u32 flags,
+			  enum bpf_prog_type type)
+{
+	struct bpf_prog *prog = ERR_PTR(-EINVAL);
+	bool id = flags & BPF_F_ID;
+
+	if (id)
+		prog = bpf_prog_by_id(id_or_fd);
+	else if (id_or_fd)
+		prog = bpf_prog_get(id_or_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+	if (type && prog->type != type) {
+		bpf_prog_put(prog);
+		return -EINVAL;
+	}
+
+	tuple->link = NULL;
+	tuple->prog = prog;
+	return 0;
+}
+
+static int bpf_mprog_tuple_relative(struct bpf_tuple *tuple,
+				    u32 id_or_fd, u32 flags,
+				    enum bpf_prog_type type)
+{
+	bool link = flags & BPF_F_LINK;
+	bool id = flags & BPF_F_ID;
+
+	memset(tuple, 0, sizeof(*tuple));
+	if (link)
+		return bpf_mprog_link(tuple, id_or_fd, flags, type);
+	/* If no relevant flag is set and no id_or_fd was passed, then
+	 * tuple link/prog is just NULLed. This is the case when before/
+	 * after selects first/last position without passing fd.
+	 */
+	if (!id && !id_or_fd)
+		return 0;
+	return bpf_mprog_prog(tuple, id_or_fd, flags, type);
+}
+
+static void bpf_mprog_tuple_put(struct bpf_tuple *tuple)
+{
+	if (tuple->link)
+		bpf_link_put(tuple->link);
+	else if (tuple->prog)
+		bpf_prog_put(tuple->prog);
+}
+
+/* The bpf_mprog_{replace,delete}() operate on exact idx position with the
+ * one exception that for deletion we support delete from front/back. In
+ * case of front idx is -1, in case of back idx is bpf_mprog_total(entry).
+ * Adjustment to first and last entry is trivial. The bpf_mprog_insert()
+ * we have to deal with the following cases:
+ *
+ * idx + before:
+ *
+ * Insert P4 before P3: idx for old array is 1, idx for new array is 2,
+ * hence we adjust target idx for the new array, so that memmove copies
+ * P1 and P2 to the new entry, and we insert P4 into idx 2. Inserting
+ * before P1 would have old idx -1 and new idx 0.
+ *
+ * +--+--+--+     +--+--+--+--+     +--+--+--+--+
+ * |P1|P2|P3| ==> |P1|P2|  |P3| ==> |P1|P2|P4|P3|
+ * +--+--+--+     +--+--+--+--+     +--+--+--+--+
+ *
+ * idx + after:
+ *
+ * Insert P4 after P2: idx for old array is 2, idx for new array is 2.
+ * Again, memmove copies P1 and P2 to the new entry, and we insert P4
+ * into idx 2. Inserting after P3 would have both old/new idx at 4 aka
+ * bpf_mprog_total(entry).
+ *
+ * +--+--+--+     +--+--+--+--+     +--+--+--+--+
+ * |P1|P2|P3| ==> |P1|P2|  |P3| ==> |P1|P2|P4|P3|
+ * +--+--+--+     +--+--+--+--+     +--+--+--+--+
+ */
+static int bpf_mprog_replace(struct bpf_mprog_entry *entry,
+			     struct bpf_mprog_entry **entry_new,
+			     struct bpf_tuple *ntuple, int idx)
+{
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	struct bpf_prog *oprog;
+
+	bpf_mprog_read(entry, idx, &fp, &cp);
+	oprog = READ_ONCE(fp->prog);
+	bpf_mprog_write(fp, cp, ntuple);
+	if (!ntuple->link) {
+		WARN_ON_ONCE(cp->link);
+		bpf_prog_put(oprog);
+	}
+	*entry_new = entry;
+	return 0;
+}
+
+static int bpf_mprog_insert(struct bpf_mprog_entry *entry,
+			    struct bpf_mprog_entry **entry_new,
+			    struct bpf_tuple *ntuple, int idx, u32 flags)
+{
+	int total = bpf_mprog_total(entry);
+	struct bpf_mprog_entry *peer;
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+
+	peer = bpf_mprog_peer(entry);
+	bpf_mprog_entry_copy(peer, entry);
+	if (idx == total)
+		goto insert;
+	else if (flags & BPF_F_BEFORE)
+		idx += 1;
+	bpf_mprog_entry_grow(peer, idx);
+insert:
+	bpf_mprog_read(peer, idx, &fp, &cp);
+	bpf_mprog_write(fp, cp, ntuple);
+	bpf_mprog_inc(peer);
+	*entry_new = peer;
+	return 0;
+}
+
+static int bpf_mprog_delete(struct bpf_mprog_entry *entry,
+			    struct bpf_mprog_entry **entry_new,
+			    struct bpf_tuple *dtuple, int idx)
+{
+	int total = bpf_mprog_total(entry);
+	struct bpf_mprog_entry *peer;
+
+	peer = bpf_mprog_peer(entry);
+	bpf_mprog_entry_copy(peer, entry);
+	if (idx == -1)
+		idx = 0;
+	else if (idx == total)
+		idx = total - 1;
+	bpf_mprog_entry_shrink(peer, idx);
+	bpf_mprog_dec(peer);
+	bpf_mprog_mark_for_release(peer, dtuple);
+	*entry_new = peer;
+	return 0;
+}
+
+/* In bpf_mprog_pos_*() we evaluate the target position for the BPF
+ * program/link that needs to be replaced, inserted or deleted for
+ * each "rule" independently. If all rules agree on that position
+ * or existing element, then enact replacement, addition or deletion.
+ * If this is not the case, then the request cannot be satisfied and
+ * we bail out with an error.
+ */
+static int bpf_mprog_pos_exact(struct bpf_mprog_entry *entry,
+			       struct bpf_tuple *tuple)
+{
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	int i;
+
+	for (i = 0; i < bpf_mprog_total(entry); i++) {
+		bpf_mprog_read(entry, i, &fp, &cp);
+		if (tuple->prog == READ_ONCE(fp->prog))
+			return tuple->link == cp->link ? i : -EBUSY;
+	}
+	return -ENOENT;
+}
+
+static int bpf_mprog_pos_before(struct bpf_mprog_entry *entry,
+				struct bpf_tuple *tuple)
+{
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	int i;
+
+	for (i = 0; i < bpf_mprog_total(entry); i++) {
+		bpf_mprog_read(entry, i, &fp, &cp);
+		if (tuple->prog == READ_ONCE(fp->prog) &&
+		    (!tuple->link || tuple->link == cp->link))
+			return i - 1;
+	}
+	return tuple->prog ? -ENOENT : -1;
+}
+
+static int bpf_mprog_pos_after(struct bpf_mprog_entry *entry,
+			       struct bpf_tuple *tuple)
+{
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	int i;
+
+	for (i = 0; i < bpf_mprog_total(entry); i++) {
+		bpf_mprog_read(entry, i, &fp, &cp);
+		if (tuple->prog == READ_ONCE(fp->prog) &&
+		    (!tuple->link || tuple->link == cp->link))
+			return i + 1;
+	}
+	return tuple->prog ? -ENOENT : bpf_mprog_total(entry);
+}
+
+int bpf_mprog_attach(struct bpf_mprog_entry *entry,
+		     struct bpf_mprog_entry **entry_new,
+		     struct bpf_prog *prog_new, struct bpf_link *link,
+		     struct bpf_prog *prog_old,
+		     u32 flags, u32 id_or_fd, u64 revision)
+{
+	struct bpf_tuple rtuple, ntuple = {
+		.prog = prog_new,
+		.link = link,
+	}, otuple = {
+		.prog = prog_old,
+		.link = link,
+	};
+	int ret, idx = -ERANGE, tidx;
+
+	if (revision && revision != bpf_mprog_revision(entry))
+		return -ESTALE;
+	if (bpf_mprog_exists(entry, prog_new))
+		return -EEXIST;
+	ret = bpf_mprog_tuple_relative(&rtuple, id_or_fd,
+				       flags & ~BPF_F_REPLACE,
+				       prog_new->type);
+	if (ret)
+		return ret;
+	if (flags & BPF_F_REPLACE) {
+		tidx = bpf_mprog_pos_exact(entry, &otuple);
+		if (tidx < 0) {
+			ret = tidx;
+			goto out;
+		}
+		idx = tidx;
+	} else if (bpf_mprog_total(entry) == bpf_mprog_max()) {
+		ret = -ERANGE;
+		goto out;
+	}
+	if (flags & BPF_F_BEFORE) {
+		tidx = bpf_mprog_pos_before(entry, &rtuple);
+		if (tidx < -1 || (idx >= -1 && tidx != idx)) {
+			ret = tidx < -1 ? tidx : -ERANGE;
+			goto out;
+		}
+		idx = tidx;
+	}
+	if (flags & BPF_F_AFTER) {
+		tidx = bpf_mprog_pos_after(entry, &rtuple);
+		if (tidx < -1 || (idx >= -1 && tidx != idx)) {
+			ret = tidx < 0 ? tidx : -ERANGE;
+			goto out;
+		}
+		idx = tidx;
+	}
+	if (idx < -1) {
+		if (rtuple.prog || flags) {
+			ret = -EINVAL;
+			goto out;
+		}
+		idx = bpf_mprog_total(entry);
+		flags = BPF_F_AFTER;
+	}
+	if (idx >= bpf_mprog_max()) {
+		ret = -ERANGE;
+		goto out;
+	}
+	if (flags & BPF_F_REPLACE)
+		ret = bpf_mprog_replace(entry, entry_new, &ntuple, idx);
+	else
+		ret = bpf_mprog_insert(entry, entry_new, &ntuple, idx, flags);
+out:
+	bpf_mprog_tuple_put(&rtuple);
+	return ret;
+}
+
+static int bpf_mprog_fetch(struct bpf_mprog_entry *entry,
+			   struct bpf_tuple *tuple, int idx)
+{
+	int total = bpf_mprog_total(entry);
+	struct bpf_mprog_cp *cp;
+	struct bpf_mprog_fp *fp;
+	struct bpf_prog *prog;
+	struct bpf_link *link;
+
+	if (idx == -1)
+		idx = 0;
+	else if (idx == total)
+		idx = total - 1;
+	bpf_mprog_read(entry, idx, &fp, &cp);
+	prog = READ_ONCE(fp->prog);
+	link = cp->link;
+	/* The deletion request can either be without filled tuple in which
+	 * case it gets populated here based on idx, or with filled tuple
+	 * where the only thing we end up doing is the WARN_ON_ONCE() assert.
+	 * If we hit a BPF link at the given index, it must not be removed
+	 * from opts path.
+	 */
+	if (link && !tuple->link)
+		return -EBUSY;
+	WARN_ON_ONCE(tuple->prog && tuple->prog != prog);
+	WARN_ON_ONCE(tuple->link && tuple->link != link);
+	tuple->prog = prog;
+	tuple->link = link;
+	return 0;
+}
+
+int bpf_mprog_detach(struct bpf_mprog_entry *entry,
+		     struct bpf_mprog_entry **entry_new,
+		     struct bpf_prog *prog, struct bpf_link *link,
+		     u32 flags, u32 id_or_fd, u64 revision)
+{
+	struct bpf_tuple rtuple, dtuple = {
+		.prog = prog,
+		.link = link,
+	};
+	int ret, idx = -ERANGE, tidx;
+
+	if (flags & BPF_F_REPLACE)
+		return -EINVAL;
+	if (revision && revision != bpf_mprog_revision(entry))
+		return -ESTALE;
+	if (!bpf_mprog_total(entry))
+		return -ENOENT;
+	ret = bpf_mprog_tuple_relative(&rtuple, id_or_fd, flags,
+				       prog ? prog->type :
+				       BPF_PROG_TYPE_UNSPEC);
+	if (ret)
+		return ret;
+	if (dtuple.prog) {
+		tidx = bpf_mprog_pos_exact(entry, &dtuple);
+		if (tidx < 0) {
+			ret = tidx;
+			goto out;
+		}
+		idx = tidx;
+	}
+	if (flags & BPF_F_BEFORE) {
+		tidx = bpf_mprog_pos_before(entry, &rtuple);
+		if (tidx < -1 || (idx >= -1 && tidx != idx)) {
+			ret = tidx < -1 ? tidx : -ERANGE;
+			goto out;
+		}
+		idx = tidx;
+	}
+	if (flags & BPF_F_AFTER) {
+		tidx = bpf_mprog_pos_after(entry, &rtuple);
+		if (tidx < -1 || (idx >= -1 && tidx != idx)) {
+			ret = tidx < 0 ? tidx : -ERANGE;
+			goto out;
+		}
+		idx = tidx;
+	}
+	if (idx < -1) {
+		if (rtuple.prog || flags) {
+			ret = -EINVAL;
+			goto out;
+		}
+		idx = bpf_mprog_total(entry);
+		flags = BPF_F_AFTER;
+	}
+	if (idx >= bpf_mprog_max()) {
+		ret = -ERANGE;
+		goto out;
+	}
+	ret = bpf_mprog_fetch(entry, &dtuple, idx);
+	if (ret)
+		goto out;
+	ret = bpf_mprog_delete(entry, entry_new, &dtuple, idx);
+out:
+	bpf_mprog_tuple_put(&rtuple);
+	return ret;
+}
+
+int bpf_mprog_query(const union bpf_attr *attr, union bpf_attr __user *uattr,
+		    struct bpf_mprog_entry *entry)
+{
+	u32 __user *uprog_flags, *ulink_flags;
+	u32 __user *uprog_id, *ulink_id;
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	struct bpf_prog *prog;
+	const u32 flags = 0;
+	u32 id, count = 0;
+	u64 revision = 1;
+	int i, ret = 0;
+
+	if (attr->query.query_flags || attr->query.attach_flags)
+		return -EINVAL;
+	if (entry) {
+		revision = bpf_mprog_revision(entry);
+		count = bpf_mprog_total(entry);
+	}
+	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.revision, &revision, sizeof(revision)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.count, &count, sizeof(count)))
+		return -EFAULT;
+	uprog_id = u64_to_user_ptr(attr->query.prog_ids);
+	uprog_flags = u64_to_user_ptr(attr->query.prog_attach_flags);
+	ulink_id = u64_to_user_ptr(attr->query.link_ids);
+	ulink_flags = u64_to_user_ptr(attr->query.link_attach_flags);
+	if (attr->query.count == 0 || !uprog_id || !count)
+		return 0;
+	if (attr->query.count < count) {
+		count = attr->query.count;
+		ret = -ENOSPC;
+	}
+	for (i = 0; i < bpf_mprog_max(); i++) {
+		bpf_mprog_read(entry, i, &fp, &cp);
+		prog = READ_ONCE(fp->prog);
+		if (!prog)
+			break;
+		id = prog->aux->id;
+		if (copy_to_user(uprog_id + i, &id, sizeof(id)))
+			return -EFAULT;
+		if (uprog_flags &&
+		    copy_to_user(uprog_flags + i, &flags, sizeof(flags)))
+			return -EFAULT;
+		id = cp->link ? cp->link->id : 0;
+		if (ulink_id &&
+		    copy_to_user(ulink_id + i, &id, sizeof(id)))
+			return -EFAULT;
+		if (ulink_flags &&
+		    copy_to_user(ulink_flags + i, &flags, sizeof(flags)))
+			return -EFAULT;
+		if (i + 1 == count)
+			break;
+	}
+	return ret;
+}