Commit bbb1cfdd authored by Jordan Rife's avatar Jordan Rife Committed by Martin KaFai Lau
Browse files

selftests/bpf: Implement socket kfuncs for bpf_testmod 



This patch adds a set of kfuncs to bpf_testmod that can be used to
manipulate a socket from kernel space.

Signed-off-by: default avatarJordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240429214529.2644801-3-jrife@google.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 8e667a06

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c

+255 −0
Original line number Diff line number Diff line
@@ -10,18 +10,30 @@ 
#include <linux/percpu-defs.h>

#include <linux/sysfs.h>

#include <linux/tracepoint.h>

#include <linux/net.h>

#include <linux/socket.h>

#include <linux/nsproxy.h>

#include <linux/inet.h>

#include <linux/in.h>

#include <linux/in6.h>

#include <linux/un.h>

#include <net/sock.h>

#include "bpf_testmod.h"

#include "bpf_testmod_kfunc.h"



#define CREATE_TRACE_POINTS

#include "bpf_testmod-events.h"



#define CONNECT_TIMEOUT_SEC 1



typedef int (*func_proto_typedef)(long);

typedef int (*func_proto_typedef_nested1)(func_proto_typedef);

typedef int (*func_proto_typedef_nested2)(func_proto_typedef_nested1);



DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123;

long bpf_testmod_test_struct_arg_result;

static DEFINE_MUTEX(sock_lock);

static struct socket *sock;



struct bpf_testmod_struct_arg_1 {

	int a;
@@ -498,6 +510,237 @@ __bpf_kfunc void bpf_kfunc_call_test_sleepable(void) 
{

}



__bpf_kfunc int bpf_kfunc_init_sock(struct init_sock_args *args)

{

	int proto;

	int err;



	mutex_lock(&sock_lock);



	if (sock) {

		pr_err("%s called without releasing old sock", __func__);

		err = -EPERM;

		goto out;

	}



	switch (args->af) {

	case AF_INET:

	case AF_INET6:

		proto = args->type == SOCK_STREAM ? IPPROTO_TCP : IPPROTO_UDP;

		break;

	case AF_UNIX:

		proto = PF_UNIX;

		break;

	default:

		pr_err("invalid address family %d\n", args->af);

		err = -EINVAL;

		goto out;

	}



	err = sock_create_kern(current->nsproxy->net_ns, args->af, args->type,

			       proto, &sock);



	if (!err)

		/* Set timeout for call to kernel_connect() to prevent it from hanging,

		 * and consider the connection attempt failed if it returns

		 * -EINPROGRESS.

		 */

		sock->sk->sk_sndtimeo = CONNECT_TIMEOUT_SEC * HZ;

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc void bpf_kfunc_close_sock(void)

{

	mutex_lock(&sock_lock);



	if (sock) {

		sock_release(sock);

		sock = NULL;

	}



	mutex_unlock(&sock_lock);

}



__bpf_kfunc int bpf_kfunc_call_kernel_connect(struct addr_args *args)

{

	int err;



	if (args->addrlen > sizeof(args->addr))

		return -EINVAL;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_connect(sock, (struct sockaddr *)&args->addr,

			     args->addrlen, 0);

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_kernel_bind(struct addr_args *args)

{

	int err;



	if (args->addrlen > sizeof(args->addr))

		return -EINVAL;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_bind(sock, (struct sockaddr *)&args->addr, args->addrlen);

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_kernel_listen(void)

{

	int err;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_listen(sock, 128);

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_kernel_sendmsg(struct sendmsg_args *args)

{

	struct msghdr msg = {

		.msg_name	= &args->addr.addr,

		.msg_namelen	= args->addr.addrlen,

	};

	struct kvec iov;

	int err;



	if (args->addr.addrlen > sizeof(args->addr.addr) ||

	    args->msglen > sizeof(args->msg))

		return -EINVAL;



	iov.iov_base = args->msg;

	iov.iov_len  = args->msglen;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_sendmsg(sock, &msg, &iov, 1, args->msglen);

	args->addr.addrlen = msg.msg_namelen;

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_sock_sendmsg(struct sendmsg_args *args)

{

	struct msghdr msg = {

		.msg_name	= &args->addr.addr,

		.msg_namelen	= args->addr.addrlen,

	};

	struct kvec iov;

	int err;



	if (args->addr.addrlen > sizeof(args->addr.addr) ||

	    args->msglen > sizeof(args->msg))

		return -EINVAL;



	iov.iov_base = args->msg;

	iov.iov_len  = args->msglen;



	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, args->msglen);

	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = sock_sendmsg(sock, &msg);

	args->addr.addrlen = msg.msg_namelen;

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_kernel_getsockname(struct addr_args *args)

{

	int err;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_getsockname(sock, (struct sockaddr *)&args->addr);

	if (err < 0)

		goto out;



	args->addrlen = err;

	err = 0;

out:

	mutex_unlock(&sock_lock);



	return err;

}



__bpf_kfunc int bpf_kfunc_call_kernel_getpeername(struct addr_args *args)

{

	int err;



	mutex_lock(&sock_lock);



	if (!sock) {

		pr_err("%s called without initializing sock", __func__);

		err = -EPERM;

		goto out;

	}



	err = kernel_getpeername(sock, (struct sockaddr *)&args->addr);

	if (err < 0)

		goto out;



	args->addrlen = err;

	err = 0;

out:

	mutex_unlock(&sock_lock);



	return err;

}



BTF_KFUNCS_START(bpf_testmod_check_kfunc_ids)

BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)

BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
@@ -525,6 +768,15 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE) 
BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg)

BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)

BTF_ID_FLAGS(func, bpf_kfunc_call_test_sleepable, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_init_sock, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_close_sock, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_connect, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_bind, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_listen, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_sendmsg, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_sock_sendmsg, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_getsockname, KF_SLEEPABLE)

BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_getpeername, KF_SLEEPABLE)

BTF_KFUNCS_END(bpf_testmod_check_kfunc_ids)



static int bpf_testmod_ops_init(struct btf *btf)
@@ -655,6 +907,8 @@ static int bpf_testmod_init(void) 
		return ret;

	if (bpf_fentry_test1(0) < 0)

		return -EINVAL;

	sock = NULL;

	mutex_init(&sock_lock);

	return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);

}
@@ -668,6 +922,7 @@ static void bpf_testmod_exit(void) 
	while (refcount_read(&prog_test_struct.cnt) > 1)

		msleep(20);



	bpf_kfunc_close_sock();

	sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);

}

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h

+27 −0
Original line number Diff line number Diff line
@@ -64,6 +64,22 @@ struct prog_test_fail3 { 
	char arr2[];

};



struct init_sock_args {

	int af;

	int type;

};



struct addr_args {

	char addr[sizeof(struct __kernel_sockaddr_storage)];

	int addrlen;

};



struct sendmsg_args {

	struct addr_args addr;

	char msg[10];

	int msglen;

};



struct prog_test_ref_kfunc *

bpf_kfunc_call_test_acquire(unsigned long *scalar_ptr) __ksym;

void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
@@ -107,4 +123,15 @@ void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p); 
void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len);



void bpf_kfunc_common_test(void) __ksym;



int bpf_kfunc_init_sock(struct init_sock_args *args) __ksym;

void bpf_kfunc_close_sock(void) __ksym;

int bpf_kfunc_call_kernel_connect(struct addr_args *args) __ksym;

int bpf_kfunc_call_kernel_bind(struct addr_args *args) __ksym;

int bpf_kfunc_call_kernel_listen(void) __ksym;

int bpf_kfunc_call_kernel_sendmsg(struct sendmsg_args *args) __ksym;

int bpf_kfunc_call_sock_sendmsg(struct sendmsg_args *args) __ksym;

int bpf_kfunc_call_kernel_getsockname(struct addr_args *args) __ksym;

int bpf_kfunc_call_kernel_getpeername(struct addr_args *args) __ksym;



#endif /* _BPF_TESTMOD_KFUNC_H */