bpf: Implement an interface to register bpf_iter targets

The target can call bpf_iter_reg_target() to register itself. The needed information: target: target name seq_ops: the seq_file operations for the target init_seq_private target callback to initialize seq_priv during file open fini_seq_private target callback to clean up seq_priv during file release seq_priv_size: the private_data size needed by the seq_file operations The target name represents a target which provides a seq_ops for iterating objects. The target can provide two callback functions, init_seq_private and fini_seq_private, called during file open/release time. For example, /proc/net/{tcp6, ipv6_route, netlink, ...}, net name space needs to be setup properly during file open and released properly during file release. Function bpf_iter_unreg_target() is also implemented to unregister a particular target.

Yonghong Song committed 6 years ago

Commit ae243451 parent 8086fba3 files · +75 −1Browse files

Showing the changes to include/linux (1 of 3 files). Show all

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include/linux/bpf.h+15−0

@@ -31,6 +31,7 @@ struct seq_file; · 30 unmodified lines
31	31	struct btf;
32	32	struct btf_type;
33	33	struct exception_table_entry;
	34	+struct seq_operations;
34	35
35	36	extern struct idr btf_idr;
36	37	extern spinlock_t btf_idr_lock;
@@ -1126,6 +1127,20 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd); · 1089 unmodified lines
1126	1127	int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
1127	1128	int bpf_obj_get_user(const char __user *pathname, int flags);
1128	1129
	1130	+typedef int (bpf_iter_init_seq_priv_t)(void private_data);
	1131	+typedef void (bpf_iter_fini_seq_priv_t)(void private_data);
	1132	+
	1133	+struct bpf_iter_reg {
	1134	+ const char *target;
	1135	+ const struct seq_operations *seq_ops;
	1136	+ bpf_iter_init_seq_priv_t init_seq_private;
	1137	+ bpf_iter_fini_seq_priv_t fini_seq_private;
	1138	+ u32 seq_priv_size;
	1139	+};
	1140	+
	1141	+int bpf_iter_reg_target(struct bpf_iter_reg *reg_info);
	1142	+void bpf_iter_unreg_target(const char *target);
	1143	+
1129	1144	int bpf_percpu_hash_copy(struct bpf_map map, void key, void *value);
1130	1145	int bpf_percpu_array_copy(struct bpf_map map, void key, void *value);
1131	1146	int bpf_percpu_hash_update(struct bpf_map map, void key, void *value,