97 lines
1.6 KiB
C
97 lines
1.6 KiB
C
#include <gint/fs.h>
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#include <gint/defs/attributes.h>
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#include <unistd.h>
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#include <errno.h>
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/* File descriptor table */
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static fs_descriptor_t fdtable[FS_FD_MAX] = { 0 };
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fs_descriptor_t const *fs_get_descriptor(int fd)
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{
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if((unsigned)fd >= FS_FD_MAX)
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return NULL;
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if(fdtable[fd].type == NULL)
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return NULL;
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return &fdtable[fd];
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}
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int fs_create_descriptor(fs_descriptor_t const *data)
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{
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if(data->type == NULL)
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return -1;
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/* Leave 0/1/2 for stdin, stdout and stderr */
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for(int i = 3; i < FS_FD_MAX; i++) {
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if(fdtable[i].type == NULL) {
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fdtable[i] = *data;
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return i;
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}
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}
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return -1;
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}
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void fs_free_descriptor(int fd)
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{
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if((unsigned)fd >= FS_FD_MAX)
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return;
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fdtable[fd].type = NULL;
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fdtable[fd].data = NULL;
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}
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int open_generic(fs_descriptor_type_t *type, void *data, int fd)
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{
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if(!type) {
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errno = EINVAL;
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return -1;
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}
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fs_descriptor_t d = {
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.type = type,
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.data = data
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};
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/* Re-use file descriptor mode */
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if(fd >= 0) {
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if(fd >= FS_FD_MAX) {
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errno = EBADF;
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return -1;
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}
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if(fdtable[fd].type) {
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errno = ENFILE;
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return -1;
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}
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fdtable[fd] = d;
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return fd;
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}
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/* Normal allocation mode */
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else {
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return fs_create_descriptor(&d);
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}
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}
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/* Standard streams */
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static fs_descriptor_type_t devnull = {
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.read = NULL,
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.pread = NULL,
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.write = NULL,
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.lseek = NULL,
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.close = NULL,
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};
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GCONSTRUCTOR static void init_standard_streams(void)
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{
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fdtable[STDIN_FILENO].type = &devnull;
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fdtable[STDIN_FILENO].data = NULL;
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fdtable[STDOUT_FILENO].type = &devnull;
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fdtable[STDOUT_FILENO].data = NULL;
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fdtable[STDERR_FILENO].type = &devnull;
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fdtable[STDERR_FILENO].data = NULL;
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}
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