static NTSTATUS cmd_write(struct vfs_state *vfs, TALLOC_CTX *mem_ctx, int argc, const char **argv) { int fd, size, wsize; if (argc != 3) { printf("Usage: write <fd> <size>\n"); return NT_STATUS_OK; } /* some error checking should go here */ fd = atoi(argv[1]); size = atoi(argv[2]); if (vfs->data == NULL) { printf("write: error=-1 (buffer empty, please populate it before writing)"); return NT_STATUS_UNSUCCESSFUL; } if (vfs->data_size < size) { printf("write: error=-1 (buffer too small, please put some more data in)"); return NT_STATUS_UNSUCCESSFUL; } wsize = SMB_VFS_WRITE(vfs->files[fd], fd, vfs->data, size); if (wsize == -1) { printf("write: error=%d (%s)\n", errno, strerror(errno)); return NT_STATUS_UNSUCCESSFUL; } printf("write: ok\n"); return NT_STATUS_OK; }
ssize_t vfs_write_data(struct smb_request *req, files_struct *fsp, const char *buffer, size_t N) { size_t total=0; ssize_t ret; if (req && req->unread_bytes) { SMB_ASSERT(req->unread_bytes == N); /* VFS_RECVFILE must drain the socket * before returning. */ req->unread_bytes = 0; return SMB_VFS_RECVFILE(smbd_server_fd(), fsp, (SMB_OFF_T)-1, N); } while (total < N) { ret = SMB_VFS_WRITE(fsp, buffer + total, N - total); if (ret == -1) return -1; if (ret == 0) return total; total += ret; } return (ssize_t)total; }
static int strict_allocate_ftruncate(vfs_handle_struct *handle, files_struct *fsp, int fd, SMB_OFF_T len) { SMB_STRUCT_STAT st; SMB_OFF_T currpos = SMB_VFS_LSEEK(fsp, fd, 0, SEEK_CUR); unsigned char zero_space[4096]; SMB_OFF_T space_to_write; if (currpos == -1) return -1; if (SMB_VFS_FSTAT(fsp, fd, &st) == -1) return -1; space_to_write = len - st.st_size; #ifdef S_ISFIFO if (S_ISFIFO(st.st_mode)) return 0; #endif if (st.st_size == len) return 0; /* Shrink - just ftruncate. */ if (st.st_size > len) return sys_ftruncate(fd, len); /* Write out the real space on disk. */ if (SMB_VFS_LSEEK(fsp, fd, st.st_size, SEEK_SET) != st.st_size) return -1; space_to_write = len - st.st_size; memset(zero_space, '\0', sizeof(zero_space)); while ( space_to_write > 0) { SMB_OFF_T retlen; SMB_OFF_T current_len_to_write = MIN(sizeof(zero_space),space_to_write); retlen = SMB_VFS_WRITE(fsp,fsp->fh->fd,(char *)zero_space,current_len_to_write); if (retlen <= 0) return -1; space_to_write -= retlen; } /* Seek to where we were */ if (SMB_VFS_LSEEK(fsp, fd, currpos, SEEK_SET) != currpos) return -1; return 0; }
ssize_t vfswrap_pwrite(vfs_handle_struct *handle, files_struct *fsp, int fd, const void *data, size_t n, SMB_OFF_T offset) { ssize_t result; #if defined(HAVE_PWRITE) || defined(HAVE_PRWITE64) START_PROFILE_BYTES(syscall_pwrite, n); result = sys_pwrite(fd, data, n, offset); END_PROFILE(syscall_pwrite); if (result == -1 && errno == ESPIPE) { /* Maintain the fiction that pipes can be sought on. */ result = SMB_VFS_WRITE(fsp, fd, data, n); } #else /* HAVE_PWRITE */ SMB_OFF_T curr; int lerrno; curr = SMB_VFS_LSEEK(fsp, fd, 0, SEEK_CUR); if (curr == -1) { return -1; } if (SMB_VFS_LSEEK(fsp, fd, offset, SEEK_SET) == -1) { return -1; } result = SMB_VFS_WRITE(fsp, fd, data, n); lerrno = errno; SMB_VFS_LSEEK(fsp, fd, curr, SEEK_SET); errno = lerrno; #endif /* HAVE_PWRITE */ return result; }
ssize_t vfs_write_data(files_struct *fsp,const char *buffer,size_t N) { size_t total=0; ssize_t ret; while (total < N) { ret = SMB_VFS_WRITE(fsp,fsp->fh->fd,buffer + total,N - total); if (ret == -1) return -1; if (ret == 0) return total; total += ret; } return (ssize_t)total; }
int vfswrap_ftruncate(vfs_handle_struct *handle, files_struct *fsp, int fd, SMB_OFF_T len) { int result = -1; SMB_STRUCT_STAT st; char c = 0; SMB_OFF_T currpos; START_PROFILE(syscall_ftruncate); if (lp_strict_allocate(SNUM(fsp->conn))) { result = strict_allocate_ftruncate(handle, fsp, fd, len); END_PROFILE(syscall_ftruncate); return result; } /* we used to just check HAVE_FTRUNCATE_EXTEND and only use sys_ftruncate if the system supports it. Then I discovered that you can have some filesystems that support ftruncate expansion and some that don't! On Linux fat can't do ftruncate extend but ext2 can. */ result = sys_ftruncate(fd, len); if (result == 0) goto done; /* According to W. R. Stevens advanced UNIX prog. Pure 4.3 BSD cannot extend a file with ftruncate. Provide alternate implementation for this */ currpos = SMB_VFS_LSEEK(fsp, fd, 0, SEEK_CUR); if (currpos == -1) { goto done; } /* Do an fstat to see if the file is longer than the requested size in which case the ftruncate above should have succeeded or shorter, in which case seek to len - 1 and write 1 byte of zero */ if (SMB_VFS_FSTAT(fsp, fd, &st) == -1) { goto done; } #ifdef S_ISFIFO if (S_ISFIFO(st.st_mode)) { result = 0; goto done; } #endif if (st.st_size == len) { result = 0; goto done; } if (st.st_size > len) { /* the sys_ftruncate should have worked */ goto done; } if (SMB_VFS_LSEEK(fsp, fd, len-1, SEEK_SET) != len -1) goto done; if (SMB_VFS_WRITE(fsp, fd, &c, 1)!=1) goto done; /* Seek to where we were */ if (SMB_VFS_LSEEK(fsp, fd, currpos, SEEK_SET) != currpos) goto done; result = 0; done: END_PROFILE(syscall_ftruncate); return result; }