diff options
Diffstat (limited to 'sysfile.c')
| -rw-r--r-- | sysfile.c | 328 |
1 files changed, 142 insertions, 186 deletions
@@ -15,120 +15,117 @@ #include "file.h" #include "fcntl.h" -int -sys_pipe(void) +// Fetch the nth word-sized system call argument as a file descriptor +// and return both the descriptor and the corresponding struct file. +static int +argfd(int argno, int *pfd, struct file **pf) { - struct file *rfd = 0, *wfd = 0; - int f1 = -1, f2 = -1; + int fd; + struct file *f; struct proc *p = curproc[cpu()]; - uint fdp; - - if(pipe_alloc(&rfd, &wfd) < 0) - goto oops; - if((f1 = fdalloc()) < 0) - goto oops; - p->ofile[f1] = rfd; - if((f2 = fdalloc()) < 0) - goto oops; - p->ofile[f2] = wfd; - if(fetcharg(0, &fdp) < 0) - goto oops; - if(putint(p, fdp, f1) < 0) - goto oops; - if(putint(p, fdp+4, f2) < 0) - goto oops; + + if(argint(argno, &fd) < 0) + return -1; + if(fd < 0 || fd >= NOFILE || (f=p->ofile[fd]) == 0) + return -1; + if(pfd) + *pfd = fd; + if(pf) + *pf = f; return 0; +} - oops: - if(rfd) - fileclose(rfd); - if(wfd) - fileclose(wfd); - if(f1 >= 0) - p->ofile[f1] = 0; - if(f2 >= 0) - p->ofile[f2] = 0; +// Allocate a file descriptor for the given file. +// Takes over file reference from caller on success. +static int +fdalloc(struct file *f) +{ + int fd; + struct proc *p = curproc[cpu()]; + for(fd = 0; fd < NOFILE; fd++){ + if(p->ofile[fd] == 0){ + p->ofile[fd] = f; + return fd; + } + } return -1; } int -sys_write(void) +sys_pipe(void) { - int fd, n, ret; - uint addr; + int *fd; + struct file *rf = 0, *wf = 0; + int fd0, fd1; struct proc *p = curproc[cpu()]; - if(fetcharg(0, &fd) < 0 || - fetcharg(1, &addr) < 0 || - fetcharg(2, &n) < 0) - return -1; - if(fd < 0 || fd >= NOFILE) + if(argptr(0, (void*)&fd, 2*sizeof fd[0]) < 0) return -1; - if(p->ofile[fd] == 0) + if(pipe_alloc(&rf, &wf) < 0) return -1; - if(addr + n > p->sz) + fd0 = -1; + if((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0){ + if(fd0 >= 0) + p->ofile[fd0] = 0; + fileclose(rf); + fileclose(wf); return -1; + } + return 0; +} + +int +sys_write(void) +{ + struct file *f; + int n; + char *cp; - ret = filewrite(p->ofile[fd], p->mem + addr, n); - return ret; + if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &cp, n) < 0) + return -1; + return filewrite(f, cp, n); } int sys_read(void) { - int fd, n, ret; - uint addr; - struct proc *p = curproc[cpu()]; + struct file *f; + int n; + char *cp; - if(fetcharg(0, &fd) < 0 || - fetcharg(1, &addr) < 0 || - fetcharg(2, &n) < 0) - return -1; - if(fd < 0 || fd >= NOFILE) - return -1; - if(p->ofile[fd] == 0) + if(argfd(0, 0, &f) < 0 || argint(2, &n) < 0 || argptr(1, &cp, n) < 0) return -1; - if(addr + n > p->sz) - return -1; - ret = fileread(p->ofile[fd], p->mem + addr, n); - return ret; + return fileread(f, cp, n); } int sys_close(void) { int fd; - struct proc *p = curproc[cpu()]; - - if(fetcharg(0, &fd) < 0) - return -1; - if(fd < 0 || fd >= NOFILE) + struct file *f; + + if(argfd(0, &fd, &f) < 0) return -1; - if(p->ofile[fd] == 0) - return -1; - fileclose(p->ofile[fd]); - p->ofile[fd] = 0; + curproc[cpu()]->ofile[fd] = 0; + fileclose(f); return 0; } int sys_open(void) { - struct proc *cp = curproc[cpu()]; struct inode *ip, *dp; - uint arg0, arg1; - int ufd; - struct file *fd; - int l; + char *path; + int omode; + int fd; + struct file *f; char *last; - if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0) - return -1; - if((l = checkstring(arg0)) < 0) + if(argstr(0, &path) < 0 || argint(1, &omode) < 0) return -1; - if(arg1 & O_CREATE){ - dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, &ip); + if(omode & O_CREATE){ + dp = namei(path, NAMEI_CREATE, 0, &last, &ip); if(dp){ ip = mknod1(dp, last, T_FILE, 0, 0); iput(dp); @@ -141,86 +138,77 @@ sys_open(void) return -1; } } else { - ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0); + ip = namei(path, NAMEI_LOOKUP, 0, 0, 0); if(ip == 0) return -1; } - if(ip->type == T_DIR && ((arg1 & O_RDWR) || (arg1 & O_WRONLY))){ + if(ip->type == T_DIR && ((omode & O_RDWR) || (omode & O_WRONLY))){ iput(ip); return -1; } - if((fd = filealloc()) == 0){ + if((f = filealloc()) == 0){ iput(ip); return -1; } - if((ufd = fdalloc()) < 0){ + if((fd = fdalloc(f)) < 0){ iput(ip); - fileclose(fd); + fileclose(f); return -1; } iunlock(ip); - fd->type = FD_FILE; - if(arg1 & O_RDWR) { - fd->readable = 1; - fd->writable = 1; - } else if(arg1 & O_WRONLY) { - fd->readable = 0; - fd->writable = 1; + f->type = FD_FILE; + if(omode & O_RDWR) { + f->readable = 1; + f->writable = 1; + } else if(omode & O_WRONLY) { + f->readable = 0; + f->writable = 1; } else { - fd->readable = 1; - fd->writable = 0; + f->readable = 1; + f->writable = 0; } - fd->ip = ip; - fd->off = 0; - cp->ofile[ufd] = fd; + f->ip = ip; + f->off = 0; - return ufd; + return fd; } int sys_mknod(void) { - struct proc *cp = curproc[cpu()]; struct inode *nip; - uint arg0, arg1, arg2, arg3; - int l; - - if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0 || - fetcharg(2, &arg2) < 0 || fetcharg(3, &arg3) < 0) + char *path; + int len; + int type, major, minor; + + if((len=argstr(0, &path)) < 0 || argint(1, &type) < 0 || + argint(2, &major) < 0 || argint(3, &minor) < 0) return -1; - if((l = checkstring(arg0)) < 0) + if(len >= DIRSIZ) return -1; - if(l >= DIRSIZ) + if((nip = mknod(path, type, major, minor)) == 0) return -1; - - nip = mknod(cp->mem + arg0, (short) arg1, (short) arg2, (short) arg3); - if(nip) - iput(nip); - return (nip == 0) ? -1 : 0; + iput(nip); + return 0; } int sys_mkdir(void) { - struct proc *cp = curproc[cpu()]; struct inode *nip; struct inode *dp; - uint arg0; - int l; + char *path; struct dirent de; char *last; - if(fetcharg(0, &arg0) < 0) - return -1; - - if((l = checkstring(arg0)) < 0) + if(argstr(0, &path) < 0) return -1; - dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, 0); + dp = namei(path, NAMEI_CREATE, 0, &last, 0); if(dp == 0) return -1; @@ -248,25 +236,20 @@ sys_mkdir(void) return 0; } - int sys_chdir(void) { - struct proc *cp = curproc[cpu()]; + struct proc *p = curproc[cpu()]; struct inode *ip; - uint arg0; - int l; - - if(fetcharg(0, &arg0) < 0) - return -1; + char *path; - if((l = checkstring(arg0)) < 0) + if(argstr(0, &path) < 0) return -1; - if((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0)) == 0) + if((ip = namei(path, NAMEI_LOOKUP, 0, 0, 0)) == 0) return -1; - if(ip == cp->cwd) { + if(ip == p->cwd) { iput(ip); return 0; } @@ -276,100 +259,74 @@ sys_chdir(void) return -1; } - idecref(cp->cwd); - cp->cwd = ip; - iunlock(cp->cwd); + idecref(p->cwd); + p->cwd = ip; + iunlock(p->cwd); return 0; } int sys_unlink(void) { - struct proc *cp = curproc[cpu()]; - uint arg0; - int r; - - if(fetcharg(0, &arg0) < 0) + char *path; + + if(argstr(0, &path) < 0) return -1; - if(checkstring(arg0) < 0) - return -1; - r = unlink(cp->mem + arg0); - return r; + return unlink(path); } int sys_fstat(void) { - struct proc *cp = curproc[cpu()]; - uint fd, addr; - int r; - - if(fetcharg(0, &fd) < 0) - return -1; - if(fetcharg(1, &addr) < 0) - return -1; - if(fd < 0 || fd >= NOFILE) - return -1; - if(cp->ofile[fd] == 0) - return -1; - if(addr + sizeof(struct stat) > cp->sz) + struct file *f; + struct stat *st; + + if(argfd(0, 0, &f) < 0 || argptr(1, (void*)&st, sizeof *st) < 0) return -1; - r = filestat(cp->ofile[fd], (struct stat*)(cp->mem + addr)); - return r; + return filestat(f, st); } int sys_dup(void) { - struct proc *cp = curproc[cpu()]; - uint fd, ufd1; - - if(fetcharg(0, &fd) < 0) - return -1; - if(fd < 0 || fd >= NOFILE) - return -1; - if(cp->ofile[fd] == 0) + struct file *f; + int fd; + + if(argfd(0, 0, &f) < 0) return -1; - if((ufd1 = fdalloc()) < 0) + if((fd=fdalloc(f)) < 0) return -1; - cp->ofile[ufd1] = cp->ofile[fd]; - fileincref(cp->ofile[ufd1]); - return ufd1; + fileincref(f); + return fd; } int sys_link(void) { - struct proc *cp = curproc[cpu()]; - uint name1, name2; - int r; - - if(fetcharg(0, &name1) < 0 || checkstring(name1) < 0) - return -1; - if(fetcharg(1, &name2) < 0 || checkstring(name2) < 0) + char *old, *new; + + if(argstr(0, &old) < 0 || argstr(1, &new) < 0) return -1; - r = link(cp->mem + name1, cp->mem + name2); - return r; + return link(old, new); } int sys_exec(void) { struct proc *cp = curproc[cpu()]; - uint arg0, arg1, sz=0, ap, sp, p1, p2; + uint sz=0, ap, sp, p1, p2; int i, nargs, argbytes, len; struct inode *ip; struct elfhdr elf; struct proghdr ph; char *mem = 0; - - if(fetcharg(0, &arg0) < 0) - return -1; - if(fetcharg(1, &arg1) < 0) + char *path, *s; + uint argv; + + if(argstr(0, &path) < 0 || argint(1, (int*)&argv) < 0) return -1; - if(checkstring(arg0) < 0) - return -1; - ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0); + + ip = namei(path, NAMEI_LOOKUP, 0, 0, 0); if(ip == 0) return -1; @@ -399,15 +356,14 @@ sys_exec(void) goto bad; memset(mem, 0, sz); - // arg1 is a pointer to an array of pointers to string. nargs = 0; argbytes = 0; - for(i = 0; ; i++){ - if(fetchint(cp, arg1 + 4*i, &ap) < 0) + for(i = 0;; i++){ + if(fetchint(cp, argv + 4*i, (int*)&ap) < 0) goto bad; if(ap == 0) break; - len = checkstring(ap); + len = fetchstr(cp, ap, &s); if(len < 0) goto bad; nargs++; @@ -432,9 +388,9 @@ sys_exec(void) p1 = sp + 12; p2 = sp + 12 + (nargs + 1) * 4; for(i = 0; i < nargs; i++){ - fetchint(cp, arg1 + 4*i, &ap); - len = checkstring(ap); - memmove(mem + p2, cp->mem + ap, len + 1); + fetchint(cp, argv + 4*i, (int*)&ap); + len = fetchstr(cp, ap, &s); + memmove(mem + p2, s, len + 1); *(uint*)(mem + p1) = p2; p1 += 4; p2 += len + 1; |