Improve quality of uname/gethostname/getdomainname

This commit is contained in:
Justine Tunney 2022-09-03 19:07:19 -07:00
parent c5c4dfcd21
commit b66bd064d8
13 changed files with 334 additions and 151 deletions

View file

@ -12,8 +12,10 @@
#include "libc/stdio/stdio.h"
int main(int argc, char *argv[]) {
char hostname[254];
CHECK_NE(-1, gethostname(hostname, sizeof(hostname)));
puts(hostname);
char name[254];
CHECK_NE(-1, gethostname(name, sizeof(name)));
printf("gethostname() → %`'s\n", name);
CHECK_NE(-1, getdomainname(name, sizeof(name)));
printf("getdomainname() → %`'s\n", name);
return 0;
}

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@ -14,11 +14,11 @@
int main(int argc, char *argv[]) {
struct utsname names;
if (uname(&names)) return 1;
printf("%-10s %s\n", "sysname", names.sysname);
printf("%-10s %s\n", "nodename", names.nodename);
printf("%-10s %s\n", "release", names.release);
printf("%-10s %s\n", "version", names.version);
printf("%-10s %s\n", "machine", names.machine);
printf("%-10s %s\n", "domainname", names.domainname);
printf("%-10s %`'s\n", "sysname", names.sysname);
printf("%-10s %`'s\n", "release", names.release);
printf("%-10s %`'s\n", "version", names.version);
printf("%-10s %`'s\n", "machine", names.machine);
printf("%-10s %`'s\n", "nodename", names.nodename);
printf("%-10s %`'s\n", "domainname", names.domainname);
return 0;
}

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@ -0,0 +1,33 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/struct/utsname-linux.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
int getdomainname_linux(char *name, size_t len) {
struct utsname_linux uts;
if (!sys_uname_linux(&uts)) {
if (memccpy(name, uts.domainname, '\0', len)) {
return 0;
} else {
return enametoolong();
}
}
return -1;
}

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@ -17,37 +17,65 @@
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/utsname.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/syscall_support-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/kprintf.h"
#include "libc/macros.internal.h"
#include "libc/nt/enum/computernameformat.h"
#include "libc/nt/errors.h"
#include "libc/nt/runtime.h"
#include "libc/nt/systeminfo.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
#define KERN_DOMAINNAME 22
/**
* Returns domain of current host.
*
* For example, if the fully-qualified hostname is "host.domain.example"
* then this SHOULD return "domain.example" however, it might not be the
* case; it depends on how the host machine is configured.
*
* The nul / mutation semantics are tricky. Here is some safe copypasta:
*
* char domain[254];
* if (getdomainname(domain, sizeof(domain))) {
* strcpy(domain, "(none)");
* }
*
* On Linux this is the same as `/proc/sys/kernel/domainname`. However,
* we turn the weird `"(none)"` string into empty string.
*
* @param name receives output name, which is guaranteed to be complete
* and have a nul-terminator if this function return zero
* @param len is size of `name` consider using `DNS_NAME_MAX + 1` (254)
* @raise EINVAL if `len` is negative
* @raise EFAULT if `name` is an invalid address
* @raise ENAMETOOLONG if the underlying system call succeeded, but the
* returned hostname had a length equal to or greater than `len` in
* which case this error is raised and the buffer is modified, with
* as many bytes of hostname as possible excluding a nul-terminator
* @return 0 on success, or -1 w/ errno
*/
int getdomainname(char *name, size_t len) {
uint32_t nSize;
struct utsname u;
char16_t name16[256];
if (len < 1) return einval();
if (!name) return efault();
if (!IsWindows()) {
if (uname(&u) == -1) return -1;
if (!memccpy(name, u.domainname[0] ? u.domainname : u.nodename, '\0',
len)) {
name[len - 1] = '\0';
}
return 0;
int rc;
if (len < 0) {
rc = einval();
} else if (!len) {
rc = 0;
} else if (!name) {
rc = efault();
} else if (IsLinux()) {
rc = getdomainname_linux(name, len);
} else if (IsBsd()) {
rc = gethostname_bsd(name, len, KERN_DOMAINNAME);
} else if (IsWindows()) {
rc = gethostname_nt(name, len, kNtComputerNamePhysicalDnsDomain);
} else {
nSize = ARRAYLEN(name16);
if (GetComputerNameEx(kNtComputerNameDnsFullyQualified, name16, &nSize)) {
tprecode16to8(name, len, name16);
return 0;
} else {
return __winerr();
}
rc = enosys();
}
if (!rc && len && !strcmp(name, "(none)")) {
name[0] = 0;
}
STRACE("getdomainname([%#.*s], %'zu) → %d% m", len, name, len, rc);
return rc;
}

View file

@ -17,26 +17,19 @@
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/calls.h"
#include "libc/calls/syscall_support-sysv.internal.h"
#include "libc/errno.h"
#include "libc/str/str.h"
#define CTL_KERN 1
#define KERN_HOSTNAME 10
#define CTL_KERN 1
int gethostname_bsd(char *name, size_t len) {
char *p;
int cmd[2];
char buf[254];
size_t buflen;
cmd[0] = CTL_KERN;
cmd[1] = KERN_HOSTNAME;
buflen = sizeof(buf);
if (sysctl(cmd, 2, buf, &buflen, NULL, 0) == -1) {
if (errno == ENOMEM) errno = ENAMETOOLONG;
int gethostname_bsd(char *name, size_t len, int kind) {
int cmd[2] = {CTL_KERN, kind};
if (sysctl(cmd, 2, name, &len, 0, 0) != -1) {
return 0;
} else {
if (errno == ENOMEM) {
errno = ENAMETOOLONG;
}
return -1;
}
strncpy(name, buf, len);
name[len - 1] = '\0';
if ((p = strchr(name, '.'))) *p = '\0';
return 0;
}

View file

@ -16,15 +16,19 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/utsname.h"
#include "libc/calls/struct/utsname-linux.internal.h"
#include "libc/calls/syscall_support-sysv.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
int gethostname_linux(char *name, size_t len) {
struct utsname u;
if (uname(&u) == -1) return -1;
memccpy(name, u.nodename, '\0', len);
name[len - 1] = '\0';
return 0;
struct utsname_linux uts;
if (!sys_uname_linux(&uts)) {
if (memccpy(name, uts.nodename, '\0', len)) {
return 0;
} else {
return enametoolong();
}
}
return -1;
}

View file

@ -22,13 +22,22 @@
#include "libc/nt/enum/computernameformat.h"
#include "libc/nt/systeminfo.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
// Guarantees NUL-terminator, if zero is returned.
// Mutates on ENAMETOOLONG without nul-terminator.
textwindows int gethostname_nt(char *name, size_t len, int kind) {
uint32_t nSize;
char name8[256];
char16_t name16[256];
nSize = ARRAYLEN(name16);
if (GetComputerNameEx(kind, name16, &nSize)) {
tprecode16to8(name, len, name16);
tprecode16to8(name8, sizeof(name8), name16);
if (memccpy(name, name8, '\0', len)) {
return 0;
} else {
return enametoolong();
}
return 0;
} else {
return __winerr();

View file

@ -17,29 +17,60 @@
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/calls.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/syscall_support-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/kprintf.h"
#include "libc/nt/enum/computernameformat.h"
#include "libc/sysv/errfuns.h"
#define KERN_HOSTNAME 10
/**
* Returns name of host system, e.g.
* Returns name of current host.
*
* pheidippides.domain.example
* ^^^^^^^^^^^^
* For example, if the fully-qualified hostname is "host.domain.example"
* then this SHOULD return "host" however that might not be the case; it
* depends on how the host machine is configured. It's fair to say if it
* has a dot, it's a FQDN, otherwise it's a node.
*
* @return 0 on success or -1 w/ errno
* The nul / mutation semantics are tricky. Here is some safe copypasta:
*
* char host[254];
* if (gethostname(host, sizeof(host))) {
* strcpy(host, "localhost");
* }
*
* On Linux this is the same as `/proc/sys/kernel/hostname`.
*
* @param name receives output name, which is guaranteed to be complete
* and have a nul-terminator if this function return zero
* @param len is size of `name` consider using `DNS_NAME_MAX + 1` (254)
* @raise EINVAL if `len` is negative
* @raise EFAULT if `name` is an invalid address
* @raise ENAMETOOLONG if the underlying system call succeeded, but the
* returned hostname had a length equal to or greater than `len` in
* which case this error is raised and the buffer is modified, with
* as many bytes of hostname as possible excluding a nul-terminator
* @return 0 on success, or -1 w/ errno
*/
int gethostname(char *name, size_t len) {
if (len < 1) return einval();
if (!name) return efault();
if (!IsWindows()) {
if (!IsBsd()) {
return gethostname_linux(name, len);
} else {
return gethostname_bsd(name, len);
}
int rc;
if (len < 0) {
rc = einval();
} else if (!len) {
rc = 0;
} else if (!name) {
rc = efault();
} else if (IsLinux()) {
rc = gethostname_linux(name, len);
} else if (IsBsd()) {
rc = gethostname_bsd(name, len, KERN_HOSTNAME);
} else if (IsWindows()) {
rc = gethostname_nt(name, len, kNtComputerNamePhysicalDnsHostname);
} else {
return gethostname_nt(name, len, kNtComputerNamePhysicalDnsHostname);
rc = enosys();
}
STRACE("gethostname([%#.*s], %'zu) → %d% m", len, name, len, rc);
return rc;
}

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@ -0,0 +1,19 @@
#ifndef COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_LINUX_INTERNAL_H_
#define COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_LINUX_INTERNAL_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
struct utsname_linux {
char sysname[65];
char nodename[65];
char release[65];
char version[65];
char machine[65];
char domainname[65];
};
int sys_uname_linux(struct utsname_linux *) asm("sys_uname");
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_LINUX_INTERNAL_H_ */

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@ -1,16 +0,0 @@
#ifndef COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_NETBSD_INTERNAL_H_
#define COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_NETBSD_INTERNAL_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
struct utsname_netbsd {
char sysname[256]; /* name of os */
char nodename[256]; /* name of network node */
char release[256]; /* release level */
char version[256]; /* version level */
char machine[256]; /* hardware type */
};
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_CALLS_STRUCT_UTSNAME_NETBSD_INTERNAL_H_ */

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@ -7,12 +7,12 @@
COSMOPOLITAN_C_START_
struct utsname {
char sysname[SYS_NMLN];
char nodename[SYS_NMLN];
char release[SYS_NMLN];
char version[SYS_NMLN];
char machine[SYS_NMLN];
char domainname[SYS_NMLN];
char sysname[SYS_NMLN]; /* name of os */
char nodename[SYS_NMLN]; /* name of network node */
char release[SYS_NMLN]; /* release level */
char version[SYS_NMLN]; /* version level */
char machine[SYS_NMLN]; /* hardware type */
char domainname[SYS_NMLN]; /* domain name */
};
int uname(struct utsname *);

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@ -7,11 +7,14 @@ COSMOPOLITAN_C_START_
*/
bool __is_linux_2_6_23(void) hidden;
bool32 sys_isatty_metal(int);
int __fixupnewfd(int, int) hidden;
int __notziposat(int, const char *);
int gethostname_bsd(char *, size_t) hidden;
int getdomainname_linux(char *, size_t) hidden;
int gethostname_bsd(char *, size_t, int) hidden;
int gethostname_linux(char *, size_t) hidden;
int gethostname_nt(char *, size_t, int) hidden;
int sys_msyscall(void *, size_t);
long sys_bogus(void);
void *__vdsosym(const char *, const char *) hidden;
void __onfork(void) hidden;
@ -19,7 +22,6 @@ void __restore_rt() hidden;
void __restore_rt_netbsd(void) hidden;
void cosmo2flock(uintptr_t);
void flock2cosmo(uintptr_t);
bool32 sys_isatty_metal(int);
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

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@ -16,93 +16,171 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/intrin/weaken.h"
#include "libc/calls/calls.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/struct/utsname-netbsd.internal.h"
#include "libc/calls/struct/utsname-linux.internal.h"
#include "libc/calls/struct/utsname.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/calls/syscall_support-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/log/log.h"
#include "libc/macros.internal.h"
#include "libc/nt/enum/computernameformat.h"
#include "libc/nt/struct/teb.h"
#include "libc/nt/systeminfo.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/errfuns.h"
static inline textwindows noasan int NtGetMajorVersion(void) {
#define CTL_KERN 1
#define KERN_OSTYPE 1
#define KERN_OSRELEASE 2
#define KERN_VERSION 4
#define KERN_HOSTNAME 10
#define KERN_DOMAINNAME 22
#define CTL_HW 6
#define HW_MACHINE 1
// Gets BSD sysctl() string, guaranteeing NUL-terminator.
// We ignore errors since this syscall mutates on ENOMEM.
// In that case, sysctl() doesn't guarantee the nul term.
static void GetBsdStr(int c0, int c1, char *s) {
char *p;
int e = errno;
size_t n = SYS_NMLN;
int cmd[2] = {c0, c1};
bzero(s, n), --n;
sysctl(cmd, 2, s, &n, NULL, 0);
errno = e;
// sysctl kern.version is too verbose for uname
if ((p = strchr(s, '\n'))) {
*p = 0;
}
}
// Gets NT name ignoring errors with guaranteed NUL-terminator.
static textwindows void GetNtName(char *name, int kind) {
uint32_t n = SYS_NMLN;
char16_t name16[256];
uint32_t size = ARRAYLEN(name16);
if (GetComputerNameEx(kind, name16, &size)) {
tprecode16to8(name, SYS_NMLN, name16);
} else {
name[0] = 0;
}
}
static inline textwindows noasan int GetNtMajorVersion(void) {
return NtGetPeb()->OSMajorVersion;
}
static inline textwindows noasan int NtGetMinorVersion(void) {
static inline textwindows noasan int GetNtMinorVersion(void) {
return NtGetPeb()->OSMinorVersion;
}
static inline textwindows noasan int NtGetBuildNumber(void) {
static inline textwindows noasan int GetNtBuildNumber(void) {
return NtGetPeb()->OSBuildNumber;
}
static textwindows void GetNtVersion(char *p) {
p = FormatUint32(p, GetNtMajorVersion()), *p++ = '.';
p = FormatUint32(p, GetNtMinorVersion()), *p++ = '-';
p = FormatUint32(p, GetNtBuildNumber());
}
static const char *Str(int rc, const char *s) {
return !rc ? s : "n/a";
}
/**
* Asks kernel to give us the `uname -a` data.
* Asks kernel to give us `uname -a` data.
*
* - `machine` should be one of:
*
* - `x86_64`
* - `amd64`
*
* - `sysname` should be one of:
*
* - `Linux`
* - `FreeBSD`
* - `NetBSD`
* - `OpenBSD`
* - `Darwin`
* - `Windows`
*
* - `version` contains the distro name, version, and release date. On
* FreeBSD/NetBSD/OpenBSD this may contain newline characters, which
* this polyfill hides by setting the first newline character to nul
* although the information can be restored by putting newline back.
* BSDs usually repeat the `sysname` and `release` in the `version`.
*
* - `nodename` *may* be the first label of the fully qualified hostname
* of the current host. This is equivalent to gethostname(), except we
* guarantee a NUL-terminator here with truncation, which should never
* happen unless the machine violates the DNS standard. If it has dots
* then it's fair to assume it's an FQDN. On Linux this is the same as
* the content of `/proc/sys/kernel/hostname`.
*
* - `domainname` *may* be the higher-order labels of the FQDN for this
* host. This is equivalent to getdomainname(), except we guarantee a
* NUL-terminator here with truncation, which should never happen w/o
* violating the DNS standard. If this field is not present, it'll be
* coerced to empty string. On Linux, this is the same as the content
* of `/proc/sys/kernel/domainname`.
*
* The returned fields are guaranteed to be nul-terminated.
*
* @return 0 on success, or -1 w/ errno
* @raise EFAULT if `buf` isn't valid
* @raise ENOSYS on metal
*/
int uname(struct utsname *lool) {
int uname(struct utsname *uts) {
int rc;
char *out, *p;
size_t i, j, len;
if (!lool) return efault();
if (!lool || (IsAsan() && !__asan_is_valid(lool, sizeof(*lool)))) {
if (!uts || (IsAsan() && !__asan_is_valid(uts, sizeof(*uts)))) {
rc = efault();
} else {
if (!IsWindows()) {
if (IsLinux() || IsFreebsd()) {
char tmp[sizeof(struct utsname)];
bzero(tmp, sizeof(tmp));
if ((rc = sys_uname(tmp)) != -1) {
out = (char *)lool;
for (i = j = 0;;) {
len = strlen(&tmp[j]);
if (len >= sizeof(struct utsname) - i) break;
memcpy(&out[i], &tmp[j], len + 1);
i += SYS_NMLN;
j += len;
while (j < sizeof(tmp) && tmp[j] == '\0') ++j;
if (j == sizeof(tmp)) break;
}
}
} else if (IsXnu()) {
strcpy(lool->sysname, "XNU's Not UNIX!");
gethostname_bsd(lool->nodename, sizeof(lool->nodename));
rc = 0;
} else if (IsOpenbsd()) {
strcpy(lool->sysname, "OpenBSD");
gethostname_bsd(lool->nodename, sizeof(lool->nodename));
rc = 0;
} else if (IsNetbsd()) {
strcpy(lool->sysname, "NetBSD");
gethostname_bsd(lool->nodename, sizeof(lool->nodename));
rc = 0;
} else {
rc = enosys();
} else if (IsLinux()) {
struct utsname_linux linux;
if (!(rc = sys_uname_linux(&linux))) {
stpcpy(uts->sysname, linux.sysname);
stpcpy(uts->nodename, linux.nodename);
stpcpy(uts->release, linux.release);
stpcpy(uts->version, linux.version);
stpcpy(uts->machine, linux.machine);
stpcpy(uts->domainname, linux.domainname);
if (!strcmp(uts->domainname, "(none)")) {
uts->domainname[0] = 0;
}
} else {
p = lool->release;
p = FormatUint32(p, NtGetMajorVersion()), *p++ = '.';
p = FormatUint32(p, NtGetMinorVersion()), *p++ = '-';
p = FormatUint32(p, NtGetBuildNumber());
strcpy(lool->sysname, "The New Technology");
strcpy(lool->machine, "x86_64");
rc = gethostname_nt(lool->nodename, sizeof(lool->nodename),
kNtComputerNamePhysicalDnsHostname);
rc |= gethostname_nt(lool->domainname, sizeof(lool->domainname),
kNtComputerNamePhysicalDnsDomain);
}
} else if (IsBsd()) {
GetBsdStr(CTL_KERN, KERN_OSTYPE, uts->sysname);
GetBsdStr(CTL_KERN, KERN_HOSTNAME, uts->nodename);
GetBsdStr(CTL_KERN, KERN_DOMAINNAME, uts->domainname);
GetBsdStr(CTL_KERN, KERN_OSRELEASE, uts->release);
GetBsdStr(CTL_KERN, KERN_VERSION, uts->version);
GetBsdStr(CTL_HW, HW_MACHINE, uts->machine);
rc = 0;
} else if (IsWindows()) {
stpcpy(uts->sysname, "Windows");
stpcpy(uts->machine, "x86_64");
GetNtVersion(stpcpy(uts->version, "Windows "));
GetNtVersion(uts->release);
GetNtName(uts->nodename, kNtComputerNamePhysicalDnsHostname);
GetNtName(uts->domainname, kNtComputerNamePhysicalDnsDomain);
rc = 0;
} else {
rc = enosys();
}
STRACE("uname([%s, %s, %s, %s, %s, %s]) → %d% m", lool->sysname,
lool->nodename, lool->release, lool->version, lool->machine,
lool->domainname, rc);
STRACE("uname([{%#s, %#s, %#s, %#s, %#s, %#s}]) → %d% m",
Str(rc, uts->sysname), Str(rc, uts->nodename), Str(rc, uts->release),
Str(rc, uts->version), Str(rc, uts->machine), Str(rc, uts->domainname),
rc);
return rc;
}