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
15 long host_syscall(int number, ...);
16
17 /*
18 * Sizes taken from musl's include/alltypes.h.in and expanded for LP64 hosts
19 */
20 typedef uint64_t host_dev_t;
21 typedef uint64_t host_ino_t;
22 typedef unsigned int host_mode_t;
23 typedef unsigned int host_uid_t;
24 typedef unsigned int host_gid_t;
25 typedef int64_t host_off_t;
26 typedef long host_blksize_t;
27 typedef 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 */
79 struct old_utsname {
80 char sysname[65];
81 char nodename[65];
82 char release[65];
83 char version[65];
84 char machine[65];
85 };
86
87 struct 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
132 struct host_kexec_segment {
133 void *buf;
134 int bufsz;
135 void *mem;
136 int memsz;
137 };
138
139 struct 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 */
161 int host_close(int fd);
162 int host_dup(int fd);
163 int host_exit(int code);
164 int host_fstat(int fd, struct host_kstat *sb);
165 int host_getdents64(int fd, void *dirp, int count);
166 int host_getpid(void);
167 int host_gettimeofday(struct host_timeval *a, void *b);
168 int host_ioctl(int fd, unsigned long request, unsigned long arg);
169 int host_kexec_load(unsigned long entry, unsigned long nsegs, struct host_kexec_segment *segs, unsigned long flags);
170 ssize_t host_llseek(int fd, int32_t offset_high, int32_t offset_lo, uint64_t *result, int whence);
171 int host_mkdir(const char *, host_mode_t);
172 void *host_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t off);
173 int host_mount(const char *src, const char *target, const char *type,
174 unsigned long flags, void *data);
175 int host_munmap(void *addr, size_t len);
176 int host_open(const char *path, int flags, int mode);
177 ssize_t host_read(int fd, void *buf, size_t nbyte);
178 int host_reboot(int, int, int, uintptr_t);
179 int host_select(int nfds, long *readfds, long *writefds, long *exceptfds,
180 struct host_timeval *timeout);
181 int host_stat(const char *path, struct host_kstat *sb);
182 int host_symlink(const char *path1, const char *path2);
183 int host_uname(struct old_utsname *);
184 ssize_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 */
202 static __inline bool
is_linux_error(long e)203 is_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 */
218 static __inline int
host_to_stand_errno(long e)219 host_to_stand_errno(long e)
220 {
221 assert(is_linux_error(e));
222
223 return((-e) > 34 ? EINVAL : (-e));
224 }
225 #endif
226