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os.c
489 lines (438 loc) · 15.5 KB
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os.c
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/*
Serval DNA operating system services
Copyright (C) 2010 Paul Gardner-Stephen
Copyright (C) 2012-2015 Serval Project Inc.
Copyright (C) 2016-2018 Flinders University
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#define __SERVAL_DNA__OS_INLINE
#include "constants.h"
#include "os.h"
#include "mem.h"
#include "str.h"
#include "log.h"
#include "strbuf_helpers.h"
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <fcntl.h>
#include <alloca.h>
#include <dirent.h>
#include <time.h>
#include <string.h>
#ifdef __APPLE__
#include <mach-o/dyld.h>
#include <inttypes.h> // PRIu32
#endif
void log_info_mkdir(struct __sourceloc __whence, const char *path, mode_t mode, void *UNUSED(context))
{
INFOF("mkdir %s (mode %04o)", alloca_str_toprint(path), mode);
}
int _mkdirs(struct __sourceloc __whence, const char *path, mode_t mode, MKDIR_LOG_FUNC *logger, void *log_context)
{
return _mkdirsn(__whence, path, strlen(path), mode, logger, log_context);
}
int _emkdirs(struct __sourceloc __whence, const char *path, mode_t mode, MKDIR_LOG_FUNC *logger, void *log_context)
{
if (_mkdirs(__whence, path, mode, logger, log_context) == -1)
return WHYF_perror("mkdirs(%s,%o)", alloca_str_toprint(path), mode);
return 0;
}
int _emkdirsn(struct __sourceloc __whence, const char *path, size_t len, mode_t mode, MKDIR_LOG_FUNC *logger, void *log_context)
{
if (_mkdirsn(__whence, path, len, mode, logger, log_context) == -1)
return WHYF_perror("mkdirsn(%s,%lu,%o)", alloca_toprint(-1, path, len), (unsigned long)len, mode);
return 0;
}
/* This variant must not log anything itself, because it is called by the logging subsystem, and
* that would cause infinite recursion!
*
* The path need not be NUL terminated.
*
* The logger function pointer is usually NULL, for no logging, but may be any function the caller
* supplies (for example, log_info_mkdir).
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
int _mkdirsn(struct __sourceloc whence, const char *path, size_t len, mode_t mode, MKDIR_LOG_FUNC *logger, void *log_context)
{
if (len == 0)
errno = EINVAL;
else {
char *pathfrag = alloca(len + 1);
strncpy(pathfrag, path, len)[len] = '\0';
if (mkdir(pathfrag, mode) != -1) {
if (logger)
logger(whence, pathfrag, mode, log_context);
return 0;
}
if (errno == EEXIST) {
DIR *d = opendir(pathfrag);
if (d) {
closedir(d);
return 0;
}
}
else if (errno == ENOENT) {
const char *lastsep = path + len - 1;
while (lastsep != path && *--lastsep != '/')
;
while (lastsep != path && *--lastsep == '/')
;
if (lastsep != path) {
if (_mkdirsn(whence, path, lastsep - path + 1, mode, logger, log_context) == -1)
return -1;
if (mkdir(pathfrag, mode) == -1) {
if (errno == EEXIST)
return 0;
return -1;
}
if (logger)
logger(whence, pathfrag, mode, log_context);
return 0;
}
}
}
return -1;
}
static int copy_file_bytes(struct __sourceloc __whence, const char *oldpath, const char *newpath, int mode){
int read_fd = open(oldpath, O_RDONLY);
if (read_fd == -1)
return WHYF_perror("open(%s)", alloca_str_toprint(oldpath));
int write_fd = open(newpath, O_WRONLY | O_CREAT | O_EXCL, mode);
if (write_fd == -1){
close(read_fd);
return WHYF_perror("open(%s)", alloca_str_toprint(newpath));
}
uint8_t buff[16*1024];
ssize_t r;
ssize_t w=0;
while(w>=0 && (r = read(read_fd, buff, sizeof buff))>0){
off_t offset = 0;
while(offset < r && (w = write(write_fd, buff + offset, r - offset))>0)
offset+=w;
if (w<0)
WHY_perror("write()");
}
if (r<0)
WHY_perror("read()");
close(write_fd);
close(read_fd);
if (r<0 || w<0){
unlink(newpath);
return -1;
}
return 0;
}
static int move_bytes_recursive(struct __sourceloc __whence, const char *oldpath, const char *newpath, int log_level){
struct stat st;
if (stat(oldpath, &st)==-1)
return WHYF_perror("stat(%s)", alloca_str_toprint(oldpath));
if (S_ISDIR(st.st_mode)){
DIR *dir;
struct dirent *dp;
if (mkdir(newpath, st.st_mode)==-1 && errno!=EEXIST)
return WHYF_perror("mkdir(%s)", newpath);
if (log_level != LOG_LEVEL_SILENT)
LOGF(log_level, "mkdir %s (mode %04o)", alloca_str_toprint(newpath), st.st_mode);
if ((dir = opendir(oldpath)) == NULL)
return WHYF_perror("opendir(%s)", alloca_str_toprint(oldpath));
errno=0;
size_t old_len = strlen(oldpath);
size_t new_len = strlen(newpath);
// use static buffers for temporary path construction to reduce stack usage.
static char old_buf[400];
static char new_buf[400];
if (oldpath!=old_buf){
strcpy(old_buf, oldpath);
strcpy(new_buf, newpath);
}
if (old_buf[old_len - 1]!='/')
old_buf[old_len++]='/';
old_buf[old_len]='\0';
if (new_buf[new_len - 1]!='/')
new_buf[new_len++]='/';
new_buf[new_len]='\0';
int r=0;
while (r==0 && (dp = readdir(dir)) != NULL) {
if (strcmp(dp->d_name,".")==0 || strcmp(dp->d_name,"..")==0)
continue;
strcpy(&old_buf[old_len], dp->d_name);
strcpy(&new_buf[new_len], dp->d_name);
r = move_bytes_recursive(__whence, old_buf, new_buf, log_level);
}
closedir(dir);
if (r==0)
rmdir(oldpath);
return r;
}
if (copy_file_bytes(__whence, oldpath, newpath, st.st_mode)==-1)
return -1;
unlink(oldpath);
if (log_level != LOG_LEVEL_SILENT)
LOGF(log_level, "moved %s -> %s", alloca_str_toprint(oldpath), alloca_str_toprint(newpath));
return 0;
}
int _erename(struct __sourceloc __whence, const char *oldpath, const char *newpath, int log_level)
{
if (rename(oldpath, newpath) != -1){
if (log_level != LOG_LEVEL_SILENT)
LOGF(log_level, "renamed %s -> %s", alloca_str_toprint(oldpath), alloca_str_toprint(newpath));
return 0;
}
if (errno != EXDEV)
return WHYF_perror("rename(%s,%s)", alloca_str_toprint(oldpath), alloca_str_toprint(newpath));
// rename() doesn't move files between filesystems, stream the bytes across the hard way...
// TODO test this code path as it occurs on android
return move_bytes_recursive(__whence, oldpath, newpath, log_level);
}
time_ms_t gettime_ms()
{
struct timeval nowtv;
// If gettimeofday() fails or returns an invalid value, all else is lost!
if (gettimeofday(&nowtv, NULL) == -1)
FATAL_perror("gettimeofday");
if (nowtv.tv_sec < 0 || nowtv.tv_usec < 0 || nowtv.tv_usec >= 1000000)
FATALF("gettimeofday returned tv_sec=%ld tv_usec=%ld", (long)nowtv.tv_sec, (long)nowtv.tv_usec);
return nowtv.tv_sec * 1000LL + nowtv.tv_usec / 1000;
}
time_s_t gettime()
{
struct timeval nowtv;
// If gettimeofday() fails or returns an invalid value, all else is lost!
if (gettimeofday(&nowtv, NULL) == -1)
FATAL_perror("gettimeofday");
if (nowtv.tv_sec < 0 || nowtv.tv_usec < 0 || nowtv.tv_usec >= 1000000)
FATALF("gettimeofday returned tv_sec=%ld tv_usec=%ld", (long)nowtv.tv_sec, (long)nowtv.tv_usec);
return nowtv.tv_sec;
}
// Returns sleep time remaining.
time_ms_t sleep_ms(time_ms_t milliseconds)
{
if (milliseconds <= 0)
return 0;
struct timespec delay;
struct timespec remain;
delay.tv_sec = milliseconds / 1000;
delay.tv_nsec = (milliseconds % 1000) * 1000000;
if (nanosleep(&delay, &remain) == -1 && errno != EINTR)
FATALF_perror("nanosleep(tv_sec=%ld, tv_nsec=%ld)", delay.tv_sec, delay.tv_nsec);
return remain.tv_sec * 1000ull + remain.tv_nsec / 1000000;
}
struct timeval time_ms_to_timeval(time_ms_t milliseconds)
{
struct timeval tv;
tv.tv_sec = milliseconds / 1000;
tv.tv_usec = (milliseconds % 1000) * 1000;
return tv;
}
ssize_t read_symlink(const char *path, char *buf, size_t len)
{
if (len == 0) {
struct stat stat;
if (lstat(path, &stat) == -1)
return WHYF_perror("lstat(%s)", alloca_str_toprint(path));
return stat.st_size + 1; // allow for terminating nul
}
ssize_t nr = readlink(path, buf, len);
if (nr == -1)
return WHYF_perror("readlink(%s,%p,%zu)", alloca_str_toprint(path), buf, len);
if ((size_t)nr >= len)
return WHYF("buffer overrun from readlink(%s, len=%zu)", alloca_str_toprint(path), len);
buf[nr] = '\0';
return nr;
}
ssize_t read_whole_file(const char *path, unsigned char *buffer, size_t buffer_size)
{
assert(buffer != NULL);
assert(buffer_size != 0);
if (malloc_read_whole_file(path, &buffer, &buffer_size) == -1)
return -1;
return buffer_size;
}
int malloc_read_whole_file(const char *path, unsigned char **bufp, size_t *sizp)
{
int fd = open(path, O_RDONLY);
if (fd == -1)
return WHYF_perror("open(%d,%s,O_RDONLY)", fd, alloca_str_toprint(path));
ssize_t ret;
struct stat stat;
if (fstat(fd, &stat) == -1)
ret = WHYF_perror("fstat(%d)", fd);
else if (*bufp != NULL && (size_t)stat.st_size > *sizp)
ret = WHYF("file %s (size %zu) is larger than available buffer (%zu)", alloca_str_toprint(path), (size_t)stat.st_size, *sizp);
else if (*bufp == NULL && *sizp && (size_t)stat.st_size > *sizp)
ret = WHYF("file %s (size %zu) is larger than maximum buffer (%zu)", alloca_str_toprint(path), (size_t)stat.st_size, *sizp);
else {
*sizp = (size_t)stat.st_size;
if (*bufp == NULL && (*bufp = emalloc(*sizp)) == NULL)
ret = WHYF("file %s (size %zu) does not fit into memory", alloca_str_toprint(path), *sizp);
else {
assert(*bufp != NULL);
ret = read(fd, *bufp, *sizp);
if (ret == -1)
ret = WHYF_perror("read(%d,%s,%zu)", fd, alloca_str_toprint(path), *sizp);
}
}
if (close(fd) == -1)
ret = WHYF_perror("close(%d)", fd);
return ret;
}
int get_file_meta(const char *path, struct file_meta *metap)
{
struct stat st;
if (stat(path, &st) == -1) {
if (errno != ENOENT)
return WHYF_perror("stat(%s)", path);
*metap = FILE_META_NONEXIST;
} else {
metap->mode = st.st_mode;
metap->size = st.st_size;
metap->mtime.tv_sec = st.st_mtime;
// Truncate to whole seconds to ensure that this code will work on file systems that only have
// whole-second time stamp resolution.
metap->mtime.tv_nsec = 0;
}
return 0;
}
static int cmp_timespec(const struct timespec *a, const struct timespec *b)
{
return a->tv_sec < b->tv_sec ? -1 : a->tv_sec > b->tv_sec ? 1 : a->tv_nsec < b->tv_nsec ? -1 : a->tv_nsec > b->tv_nsec ? 1 : 0;
}
static void add_timespec(struct timespec *tv, long sec, long nsec)
{
const long NANO = 1000000000;
tv->tv_sec += sec;
// Bring nsec into range -NANO < nsec < NANO.
if (nsec >= NANO) {
sec = nsec / NANO;
tv->tv_sec += sec;
nsec -= sec * NANO;
} else if (nsec <= -NANO) {
// The C standard does not define whether negative integer division truncates towards negative
// infinity or rounds towards zero. So we have to use positive integer division, which always
// truncates towards zero.
sec = -nsec / NANO;
tv->tv_sec -= sec;
nsec += sec * NANO;
}
assert(nsec > -NANO);
assert(nsec < NANO);
tv->tv_nsec += nsec;
// Bring tv_nsec into range 0 <= tv_nsec < NANO.
if (tv->tv_nsec >= NANO) {
sec = tv->tv_nsec / NANO;
tv->tv_sec += sec;
tv->tv_nsec -= sec * NANO;
} else if (tv->tv_nsec < 0) {
sec = (-tv->tv_nsec + NANO - 1) / NANO;
tv->tv_sec -= sec;
tv->tv_nsec += sec * NANO;
}
assert(tv->tv_nsec >= 0);
assert(tv->tv_nsec < NANO);
}
int cmp_file_meta(const struct file_meta *a, const struct file_meta *b)
{
int c = cmp_timespec(&a->mtime, &b->mtime);
return c ? c : a->size < b->size ? -1 : a->size > b->size ? 1 : 0;
}
/* Post-update file meta adjustment.
*
* If a file's meta information is used to detect changes to the file by polling at regular
* intervals, then every update to the file must guarantee to never produce the same meta
* information as any prior update. The typical case is several updates in rapid succession during
* one second that do not change the size of the file. The second and subsequent of these will not
* change the file's meta information (size or last-modified time stamp) on file systems that only
* have one-second timestamp resolution.
*
* This function can be called immediately after updating such a file, supplying the meta
* information from just prior to the update. It will alter the file's meta information (last
* modified time stamp) to ensure that it differs from the prior meta information. This typically
* involves advancing the file's last-modification time stamp.
*
* Returns -1 if an error occurs, 1 if it alters the file's meta information, 0 if the current meta
* information is already different and did not need alteration.
*
* @author Andrew Bettison <andrew@servalproject.com>
*/
int alter_file_meta(const char *path, const struct file_meta *origp, struct file_meta *metap)
{
long nsec = 1;
long sec = 0;
// If the file's current last-modified timestamp is not greater than its original, try bumping the
// original timestamp by one nanosecond, and if that does not alter the timestamp, the file system
// does not support nanosecond timestamps, so try bumping it by one second.
while (sec <= 1) {
struct file_meta meta;
if (get_file_meta(path, &meta) == -1)
return -1;
if (metap)
*metap = meta;
if (is_file_meta_nonexist(&meta) || cmp_timespec(&origp->mtime, &meta.mtime) < 0)
return 0;
meta.mtime = origp->mtime;
add_timespec(&meta.mtime, sec, nsec);
struct timeval times[2];
times[0] = time_ms_to_timeval(gettime_ms());
times[1].tv_sec = meta.mtime.tv_sec;
times[1].tv_usec = meta.mtime.tv_nsec / 1000;
if (utimes(path, times) == -1)
return WHYF_perror("utimes(%s,[%s,%s])", alloca_str_toprint(path), alloca_timeval(×[0]), alloca_timeval(×[1]));
nsec = 0;
++sec;
}
return 1;
}
int file_exists(const char *path)
{
struct file_meta meta;
return get_file_meta(path, &meta) != -1 && is_file_meta_exists(&meta);
}
int file_exists_is_regular(const char *path)
{
struct file_meta meta;
return get_file_meta(path, &meta) != -1 && is_file_meta_regular(&meta);
}
int file_exists_is_directory(const char *path)
{
struct file_meta meta;
return get_file_meta(path, &meta) != -1 && !is_file_meta_directory(&meta);
}
ssize_t get_self_executable_path(char *buf, size_t len)
{
#if defined(linux)
return read_symlink("/proc/self/exe", buf, len);
#elif defined (__sun__)
return read_symlink("/proc/self/path/a.out", buf, len);
#elif defined (__APPLE__)
// Ensure that len is not too large.
assert(((int32_t)len)>=0);
uint32_t bufsize = len;
ssize_t s = _NSGetExecutablePath(buf, &bufsize);
// Ensure that _NSGetExecutablePath doesn't return a gigantic value in bufsize that would be
// negative when cast.
assert(((int32_t)bufsize)>=0);
if (len == 0) {
if (s != -1)
return WHYF("_NSGetExecutablePath(%p, &%zd) returned %zd, expecting -1", buf, len, s);
return bufsize;
}
if (s == -1)
return WHYF("_NSGetExecutablePath(%p, &%zd) returned %zd, bufsize=%"PRIu32, buf, len, s, bufsize);
return strlen(buf) + 1; // include terminating nul
#else
#error Unable to find executable path
#endif
}