1/*
2 * Copyright (c) 2022, Netflix, Inc.
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Rewritten from the original host_syscall.h Copyright (C) 2014 Nathan Whitehorn
7 */
8
9#ifndef _HOST_SYSCALL_H
10#define _HOST_SYSCALL_H
11
12#include <stand.h>
13#include <assert.h>
14
15long host_syscall(int number, ...);
16
17/*
18 * Sizes taken from musl's include/alltypes.h.in and expanded for LP64 hosts
19 */
20typedef uint64_t host_dev_t;
21typedef uint64_t host_ino_t;
22typedef unsigned int host_mode_t;
23typedef unsigned int host_uid_t;
24typedef unsigned int host_gid_t;
25typedef int64_t host_off_t;
26typedef long host_blksize_t;
27typedef int64_t host_blkcnt_t;
28
29#include "stat_arch.h"
30
31/*
32 * stat flags
33 * These are arch independent and match the values in nolib and uapi headers
34 * with HOST_ prepended.
35 */
36#define	HOST_S_IFMT	0170000
37#define	HOST_S_IFIFO	0010000
38#define	HOST_S_IFCHR	0020000
39#define	HOST_S_IFDIR	0040000
40#define	HOST_S_IFBLK	0060000
41#define	HOST_S_IFREG	0100000
42#define	HOST_S_IFLNK	0120000
43#define	HOST_S_IFSOCK	0140000
44
45#define	HOST_S_ISBLK(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFBLK)
46#define	HOST_S_ISCHR(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFCHR)
47#define	HOST_S_ISDIR(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFDIR)
48#define	HOST_S_ISFIFO(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFIFO)
49#define	HOST_S_ISLNK(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFLNK)
50#define	HOST_S_ISREG(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFREG)
51#define	HOST_S_ISSOCK(mode)	(((mode) & HOST_S_IFMT) == HOST_S_IFSOCK)
52
53/*
54 * Constants for open, fcntl, etc
55 *
56 * Note: Some of these are arch dependent on Linux, but are the same for
57 * powerpc, x86, arm*, and riscv. We should be futureproof, though, since these
58 * are the 'generic' values and only older architectures (no longer supported by
59 * FreeBSD) vary.
60 *
61 * These are from tools/include/uapi/asm-generic/fcntl.h and use the octal
62 * notation. Beware, hex is used in other places creating potential confsion.
63 */
64#define HOST_O_RDONLY		    0
65#define HOST_O_WRONLY		    1
66#define HOST_O_RDWR		    2
67#define HOST_O_CREAT		00100
68#define HOST_O_EXCL		00200
69#define HOST_O_NOCTTY		00400
70#define HOST_O_TRUNC		01000
71#define HOST_O_APPEND		02000
72#define HOST_O_NONBLOCK		04000
73
74#define HOST_AT_FDCWD		-100            /* Relative to current directory */
75
76/*
77 * Data types
78 */
79struct old_utsname {
80	char sysname[65];
81	char nodename[65];
82	char release[65];
83	char version[65];
84	char machine[65];
85};
86
87struct host_timeval {
88	time_t tv_sec;
89	long tv_usec;
90};
91
92/*
93 * Must match Linux's values see linux/tools/include/uapi/asm-generic/mman-common.h
94 * and linux/tools/include/linux/mman.h
95 *
96 * And pre-pend HOST_ here.
97 */
98#define HOST_PROT_READ	0x1
99#define HOST_PROT_WRITE	0x2
100#define HOST_PROT_EXEC	0x4
101
102#define HOST_MAP_SHARED		0x01
103#define	HOST_MAP_PRIVATE	0x02
104#define HOST_MAP_FIXED		0x10
105#define HOST_MAP_ANONYMOUS	0x20
106
107#define HOST_MAP_FAILED		((void *)-1)
108
109/* Mount flags from uapi */
110#define MS_RELATIME (1 << 21)
111
112#define HOST_REBOOT_MAGIC1	0xfee1dead
113#define HOST_REBOOT_MAGIC2	672274793
114#define HOST_REBOOT_CMD_KEXEC	0x45584543
115
116/*
117 * Values from linux/tools/include/uapi/linux/kexec.h
118 */
119
120/*
121 * Values match ELF architecture types.
122 */
123#define HOST_KEXEC_ARCH_X86_64  (62 << 16)
124#define HOST_KEXEC_ARCH_PPC64   (21 << 16)
125#define HOST_KEXEC_ARCH_ARM     (40 << 16)
126#define HOST_KEXEC_ARCH_AARCH64 (183 << 16)
127#define HOST_KEXEC_ARCH_RISCV   (243 << 16)
128
129/* Arbitrary cap on segments */
130#define HOST_KEXEC_SEGMENT_MAX 16
131
132struct host_kexec_segment {
133	void *buf;
134	int bufsz;
135	void *mem;
136	int memsz;
137};
138
139struct host_dirent64 {
140	uint64_t	d_ino;		/* 64-bit inode number */
141	int64_t		d_off;		/* 64-bit offset to next structure */
142	unsigned short	d_reclen;	/* Size of this dirent */
143	unsigned char	d_type;		/* File type */
144	char		d_name[];	/* Filename (null-terminated) */
145};
146
147/* d_type values */
148#define HOST_DT_UNKNOWN		 0
149#define HOST_DT_FIFO		 1
150#define HOST_DT_CHR		 2
151#define HOST_DT_DIR		 4
152#define HOST_DT_BLK		 6
153#define HOST_DT_REG		 8
154#define HOST_DT_LNK		10
155#define HOST_DT_SOCK		12
156#define HOST_DT_WHT		14
157
158/*
159 * System Calls
160 */
161int host_close(int fd);
162int host_dup(int fd);
163int host_exit(int code);
164int host_fstat(int fd, struct host_kstat *sb);
165int host_getdents64(int fd, void *dirp, int count);
166int host_getpid(void);
167int host_gettimeofday(struct host_timeval *a, void *b);
168int host_ioctl(int fd, unsigned long request, unsigned long arg);
169int host_kexec_load(unsigned long entry, unsigned long nsegs, struct host_kexec_segment *segs, unsigned long flags);
170ssize_t host_llseek(int fd, int32_t offset_high, int32_t offset_lo, uint64_t *result, int whence);
171int host_mkdir(const char *, host_mode_t);
172void *host_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t off);
173int host_mount(const char *src, const char *target, const char *type,
174    unsigned long flags, void *data);
175int host_munmap(void *addr, size_t len);
176int host_open(const char *path, int flags, int mode);
177ssize_t host_read(int fd, void *buf, size_t nbyte);
178int host_reboot(int, int, int, uintptr_t);
179int host_select(int nfds, long *readfds, long *writefds, long *exceptfds,
180    struct host_timeval *timeout);
181int host_stat(const char *path, struct host_kstat *sb);
182int host_symlink(const char *path1, const char *path2);
183int host_uname(struct old_utsname *);
184ssize_t host_write(int fd, const void *buf, size_t nbyte);
185
186/*
187 * Wrappers / one-liners
188 */
189#define host_getmem(size) \
190	host_mmap(0, size, HOST_PROT_READ | HOST_PROT_WRITE, \
191	    HOST_MAP_PRIVATE | HOST_MAP_ANONYMOUS, -1, 0);
192
193/*
194 * Since we have to interface with the 'raw' system call, we have to cope with
195 * Linux's conventions. To run on the most architectures possible, they don't
196 * return errors through some CPU flag, but instead, return a negative value for
197 * an error, and a positive one for success. However, there's some issues since
198 * addresses have to be returned, some of which are also negative, so Linus
199 * declared that no successful result could be -4096 to 0. This implements
200 * that quirk so we can check return values easily.
201 */
202static __inline bool
203is_linux_error(long e)
204{
205	return (e < 0 && e >= -4096);
206}
207
208/*
209 * Translate Linux errno to FreeBSD errno. The two system have idenitcal errors
210 * for 1-34. After that, they differ. Linux also has errno that don't map
211 * exactly to FreeBSD's errno, plus the Linux errno are arch dependent >
212 * 34. Since we just need to do this for simple cases, use the simple mapping
213 * function where -1 to -34 are translated to 1 to 34 and all others are EINVAL.
214 * Pass the linux return value, which will be the -errno. Linux returns these
215 * values as a 'long' which has to align to CPU register size, so accept that
216 * size as the error so the assert can catch more values.
217 */
218static __inline int
219host_to_stand_errno(long e)
220{
221	assert(is_linux_error(e));
222
223	return((-e) > 34 ? EINVAL : (-e));
224}
225#endif
226