diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/sys/os/os_filedes.c | 72 |
1 files changed, 69 insertions, 3 deletions
diff --git a/src/sys/os/os_filedes.c b/src/sys/os/os_filedes.c index 11cf058..817bd47 100644 --- a/src/sys/os/os_filedes.c +++ b/src/sys/os/os_filedes.c @@ -89,6 +89,69 @@ fd_alloc(struct proc *procp, struct filedesc **fd_res) return -EMFILE; } +/* + * Look up a file descriptor that belongs to a specific + * process by using its fd number + * + * @procp: Process to look up + * @fd: File descriptor number + * + * Returns the file descriptor pointer on success, + * otherwise a less than zero value on failure + */ +static struct filedesc * +fd_get(struct proc *procp, int fd) +{ + struct filedesc *fdp; + + if (procp == NULL) { + return NULL; + } + + for (int i = 0; i < FD_MAX; ++i) { + if ((fdp = procp->fdtab[i]) == NULL) { + continue; + } + + break; + } + + return fdp; +} + + +/* + * Duplicate a file descriptor + */ +struct filedesc * +fd_dup(struct proc *procp, int fd) +{ + struct filedesc *new, *old; + int error; + + old = fd_get(procp, fd); + if (new == NULL) { + return NULL; + } + + /* We need the old vnode too */ + if (old->vp == NULL) { + return NULL; + } + + /* Allocate an even newer file descriptor */ + error = fd_alloc(procp, &new); + if (error != 0) { + return NULL; + } + + /* Grab a ref and copy */ + vnode_ref(old->vp); + new->mode = old->mode; + new->vp = old->vp; + return new; +} + int fd_open(const char *path, mode_t mode) { @@ -137,6 +200,8 @@ fd_open(const char *path, mode_t mode) int fdtab_init(struct proc *procp) { + struct filedesc *fd; + if (procp == NULL) { return -EINVAL; } @@ -147,9 +212,10 @@ fdtab_init(struct proc *procp) return -1; } - fd_alloc(procp, NULL); /* stdin */ - fd_alloc(procp, NULL); /* stdout */ - fd_alloc(procp, NULL); /* stderr */ + fd_alloc(procp, &fd); /* stdin */ + fd->mode = O_RDWR; /* all can read */ + fd_dup(procp, 0); /* stdout */ + fd_dup(procp, 0); /* stderr */ return 0; } |