Merge "Use the module bpf_syscall_wrappers for BPF system calls"

This commit is contained in:
Maciej Żenczykowski 2021-01-14 07:36:50 +00:00 committed by Gerrit Code Review
commit 6fadbcf91a
2 changed files with 3 additions and 119 deletions

View file

@ -26,6 +26,8 @@ cc_library_headers {
},
},
sdk_version: "30",
header_libs: ["bpf_syscall_wrappers"],
export_header_lib_headers: ["bpf_syscall_wrappers"],
}
cc_library {

View file

@ -17,9 +17,7 @@
#ifndef BPF_BPFUTILS_H
#define BPF_BPFUTILS_H
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/unistd.h>
#include <net/if.h>
#include <stdlib.h>
#include <string.h>
@ -27,16 +25,7 @@
#include <string>
#ifdef BPF_FD_JUST_USE_INT
#define BPF_FD_TYPE int
#define BPF_FD_TO_U32(x) static_cast<__u32>(x)
#else
#include <android-base/unique_fd.h>
#define BPF_FD_TYPE base::unique_fd&
#define BPF_FD_TO_U32(x) static_cast<__u32>((x).get())
#endif
#define ptr_to_u64(x) ((uint64_t)(uintptr_t)(x))
#include "BpfSyscallWrappers.h"
namespace android {
namespace bpf {
@ -61,113 +50,6 @@ constexpr const uint64_t NONEXISTENT_COOKIE = 0;
constexpr const int MINIMUM_API_REQUIRED = 28;
/* Note: bpf_attr is a union which might have a much larger size then the anonymous struct portion
* of it that we are using. The kernel's bpf() system call will perform a strict check to ensure
* all unused portions are zero. It will fail with E2BIG if we don't fully zero bpf_attr.
*/
inline int bpf(int cmd, const bpf_attr& attr) {
return syscall(__NR_bpf, cmd, &attr, sizeof(attr));
}
inline int createMap(bpf_map_type map_type, uint32_t key_size, uint32_t value_size,
uint32_t max_entries, uint32_t map_flags) {
return bpf(BPF_MAP_CREATE, {
.map_type = map_type,
.key_size = key_size,
.value_size = value_size,
.max_entries = max_entries,
.map_flags = map_flags,
});
}
inline int writeToMapEntry(const BPF_FD_TYPE map_fd, const void* key, const void* value,
uint64_t flags) {
return bpf(BPF_MAP_UPDATE_ELEM, {
.map_fd = BPF_FD_TO_U32(map_fd),
.key = ptr_to_u64(key),
.value = ptr_to_u64(value),
.flags = flags,
});
}
inline int findMapEntry(const BPF_FD_TYPE map_fd, const void* key, void* value) {
return bpf(BPF_MAP_LOOKUP_ELEM, {
.map_fd = BPF_FD_TO_U32(map_fd),
.key = ptr_to_u64(key),
.value = ptr_to_u64(value),
});
}
inline int deleteMapEntry(const BPF_FD_TYPE map_fd, const void* key) {
return bpf(BPF_MAP_DELETE_ELEM, {
.map_fd = BPF_FD_TO_U32(map_fd),
.key = ptr_to_u64(key),
});
}
inline int getNextMapKey(const BPF_FD_TYPE map_fd, const void* key, void* next_key) {
return bpf(BPF_MAP_GET_NEXT_KEY, {
.map_fd = BPF_FD_TO_U32(map_fd),
.key = ptr_to_u64(key),
.next_key = ptr_to_u64(next_key),
});
}
inline int getFirstMapKey(const BPF_FD_TYPE map_fd, void* firstKey) {
return getNextMapKey(map_fd, NULL, firstKey);
}
inline int bpfFdPin(const BPF_FD_TYPE map_fd, const char* pathname) {
return bpf(BPF_OBJ_PIN, {
.pathname = ptr_to_u64(pathname),
.bpf_fd = BPF_FD_TO_U32(map_fd),
});
}
inline int bpfFdGet(const char* pathname, uint32_t flag) {
return bpf(BPF_OBJ_GET, {
.pathname = ptr_to_u64(pathname),
.file_flags = flag,
});
}
inline int mapRetrieve(const char* pathname, uint32_t flag) {
return bpfFdGet(pathname, flag);
}
inline int mapRetrieveRW(const char* pathname) {
return mapRetrieve(pathname, 0);
}
inline int mapRetrieveRO(const char* pathname) {
return mapRetrieve(pathname, BPF_F_RDONLY);
}
inline int mapRetrieveWO(const char* pathname) {
return mapRetrieve(pathname, BPF_F_WRONLY);
}
inline int retrieveProgram(const char* pathname) {
return bpfFdGet(pathname, BPF_F_RDONLY);
}
inline int attachProgram(bpf_attach_type type, const BPF_FD_TYPE prog_fd,
const BPF_FD_TYPE cg_fd) {
return bpf(BPF_PROG_ATTACH, {
.target_fd = BPF_FD_TO_U32(cg_fd),
.attach_bpf_fd = BPF_FD_TO_U32(prog_fd),
.attach_type = type,
});
}
inline int detachProgram(bpf_attach_type type, const BPF_FD_TYPE cg_fd) {
return bpf(BPF_PROG_DETACH, {
.target_fd = BPF_FD_TO_U32(cg_fd),
.attach_type = type,
});
}
uint64_t getSocketCookie(int sockFd);
int synchronizeKernelRCU();
int setrlimitForTest();