This patch adds a set of kfuncs to bpf_testmod that can be used to manipulate a socket from kernel space.
Signed-off-by: Jordan Rife jrife@google.com --- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 255 ++++++++++++++++++ .../bpf/bpf_testmod/bpf_testmod_kfunc.h | 27 ++ 2 files changed, 282 insertions(+)
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index eb2b78552ca29..e93013fc7bf4d 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -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); }
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h index ce5cd763561ca..b0d586a6751fa 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h @@ -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 */