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- /*
- * The Qubes OS Project, http://www.qubes-os.org
- *
- * Copyright (C) 2010 Rafal Wojtczuk <rafal@invisiblethingslab.com>
- *
- * 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.
- *
- */
- #include <sys/types.h>
- #include <pwd.h>
- #include <stdio.h>
- #include <unistd.h>
- #include <sys/inotify.h>
- #include <fcntl.h>
- #include <stdlib.h>
- #include <xs.h>
- #include <syslog.h>
- #include <sys/stat.h>
- #include <string.h>
- #include "dvm.h"
- int parse_events(char *buf, int len)
- {
- int i = 0;
- while (i < len) {
- struct inotify_event *ev =
- (struct inotify_event *) (buf + i);
- if ((ev->mask & IN_UNMOUNT) || (ev->mask & IN_IGNORED))
- return 1;
- i += sizeof(struct inotify_event) + ev->len;
- }
- return 0;
- }
- #define BUFLEN 1024
- void wait_for_umount(char *name)
- {
- char buf[BUFLEN];
- int fd = inotify_init();
- int len;
- int ret = inotify_add_watch(fd, name, IN_ATTRIB);
- if (ret < 0) {
- perror("inotify_add_watch");
- return;
- }
- for (;;) {
- len = read(fd, buf, BUFLEN - 1);
- if (len <= 0) {
- perror("read inotify");
- return;
- }
- if (parse_events(buf, len))
- return;
- }
- }
- void background()
- {
- int i, fd;
- for (i = 0; i < 256; i++)
- close(i);
- fd = open("/dev/null", O_RDWR);
- for (i = 0; i <= 2; i++)
- dup2(fd, i);
- switch (fork()) {
- case -1:
- exit(1);
- case 0:
- break;
- default:
- exit(0);
- }
- }
- int check_legal_filename(char *name)
- {
- if (index(name, '/')) {
- syslog(LOG_DAEMON | LOG_ERR,
- "the received filename contains /");
- return 0;
- }
- return 1;
- }
- void drop_to_user()
- {
- struct passwd *pw = getpwnam("user");
- if (pw)
- setuid(pw->pw_uid);
- }
- int copy_from_xvdh(int destfd, int srcfd, unsigned long long count)
- {
- int n, size;
- char buf[4096];
- unsigned long long total = 0;
- while (total < count) {
- if (count - total > sizeof(buf))
- size = sizeof(buf);
- else
- size = count - total;
- n = read(srcfd, buf, size);
- if (n != size) {
- syslog(LOG_DAEMON | LOG_ERR, "reading xvdh");
- return 0;
- }
- if (write(destfd, buf, size) != size) {
- syslog(LOG_DAEMON | LOG_ERR, "writing file");
- return 0;
- }
- total += size;
- }
- return 1;
- }
- void redirect_stderr()
- {
- int fd =
- open("/var/log/dvm.log", O_CREAT | O_TRUNC | O_WRONLY, 0600);
- if (fd < 0) {
- syslog(LOG_DAEMON | LOG_ERR, "open dvm.log");
- exit(1);
- }
- dup2(fd, 2);
- }
- void suicide(struct xs_handle *xs)
- {
- xs_write(xs, XBT_NULL, "device/qpen", "killme", 6);
- xs_daemon_close(xs);
- exit(1);
- }
- // we are DVM, AppVM sends us a document to work on
- // /dev/xvdh contains the dvm_header and document data
- void dvm_transaction_request(char *seq, struct xs_handle *xs)
- {
- char filename[1024], cmdbuf[1024];
- struct dvm_header header;
- int xvdh_fd, file_fd;
- char *src_vm;
- unsigned int len;
- struct stat stat_pre, stat_post;
- xvdh_fd = open("/dev/xvdh", O_RDONLY);
- if (read(xvdh_fd, &header, sizeof(header)) != sizeof(header)) {
- syslog(LOG_DAEMON | LOG_ERR, "read dvm_header");
- suicide(xs);
- }
- header.name[sizeof(header.name) - 1] = 0;
- if (!check_legal_filename(header.name))
- suicide(xs);
- snprintf(filename, sizeof(filename), "/tmp/%s", header.name);
- drop_to_user();
- file_fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
- if (file_fd < 0) {
- syslog(LOG_DAEMON | LOG_ERR, "open file");
- suicide(xs);
- }
- if (!copy_from_xvdh(file_fd, xvdh_fd, header.file_size))
- suicide(xs);
- close(xvdh_fd);
- close(file_fd);
- if (stat(filename, &stat_pre)) {
- syslog(LOG_DAEMON | LOG_ERR, "stat pre");
- suicide(xs);
- }
- snprintf(cmdbuf, sizeof(cmdbuf),
- "HOME=/home/user DISPLAY=:0 /usr/bin/mimeopen -n -M '/tmp/%s' 2>&1 > /tmp/kde-open.log", header.name);
- if (system(cmdbuf))
- system("HOME=/home/user DISPLAY=:0 /usr/bin/kdialog --sorry 'Unable to handle mimetype of the requested file!'");
- if (stat(filename, &stat_post)) {
- syslog(LOG_DAEMON | LOG_ERR, "stat post");
- suicide(xs);
- }
- src_vm = xs_read(xs, XBT_NULL, "qubes_blocksrc", &len);
- xs_write(xs, XBT_NULL, "device/qpen", "umount", 6);
- if (stat_pre.st_mtime == stat_post.st_mtime)
- suicide(xs);
- xs_daemon_close(xs);
- // if the modify timestamp of the document file has changed, write back the
- // modified content to the requestor AppVM
- execl("/usr/lib/qubes/qvm-dvm-transfer", "qvm-dvm-transfer", src_vm,
- filename, seq, NULL);
- syslog(LOG_DAEMON | LOG_ERR, "execl qvm-dvm-transfer");
- suicide(xs);
- }
- // we are AppVM, DVM sends us a modified document
- // /dev/xvdh contains the dvm_header and document data
- void dvm_transaction_return(char *seq_string, struct xs_handle *xs)
- {
- int seq = strtoul(seq_string, 0, 10);
- char db_name[1024];
- char file_name[1024];
- int db_fd, file_fd, xvdh_fd;
- struct dvm_header header;
- xvdh_fd = open("/dev/xvdh", O_RDONLY);
- if (xvdh_fd < 0) {
- syslog(LOG_DAEMON | LOG_ERR, "open xvdh");
- goto out_err;
- }
- if (read(xvdh_fd, &header, sizeof(header)) != sizeof(header)) {
- syslog(LOG_DAEMON | LOG_ERR, "read dvm_header");
- goto out_err;
- }
- drop_to_user();
- // read the file name for which the open-in-dvm with transaction=="seq" was started
- snprintf(db_name, sizeof(db_name), DBDIR "/%d", seq);
- db_fd = open(db_name, O_RDONLY);
- if (!db_fd) {
- syslog(LOG_DAEMON | LOG_ERR, "open db");
- goto out_err;
- }
- if (read(db_fd, file_name, sizeof(file_name)) < 0) {
- syslog(LOG_DAEMON | LOG_ERR, "read db");
- goto out_err;
- }
- close(db_fd);
- file_fd = open(file_name, O_WRONLY | O_TRUNC);
- if (file_fd < 0) {
- syslog(LOG_DAEMON | LOG_ERR, "open filename");
- goto out_err;
- }
- copy_from_xvdh(file_fd, xvdh_fd, header.file_size);
- close(xvdh_fd);
- close(file_fd);
- out_err:
- xs_write(xs, XBT_NULL, "device/qpen", "umount", 6);
- xs_daemon_close(xs);
- }
- void dvm_transaction(char *seq, struct xs_handle *xs)
- {
- struct stat st;
- redirect_stderr();
- if (stat("/etc/this_is_dvm", &st))
- dvm_transaction_return(seq, xs);
- else
- dvm_transaction_request(seq, xs);
- }
- #define MOUNTDIR "/mnt/incoming"
- int main()
- {
- struct xs_handle *xs;
- char *seq;
- unsigned int len;
- background();
- openlog("qubes_add_pendrive_script", LOG_CONS | LOG_PID,
- LOG_DAEMON);
- xs = xs_domain_open();
- if (!xs) {
- syslog(LOG_DAEMON | LOG_ERR, "xs_domain_open");
- exit(1);
- }
- seq = xs_read(xs, XBT_NULL, "qubes_transaction_seq", &len);
- if (seq && len > 0 && strcmp(seq, "0")) {
- dvm_transaction(seq, xs);
- exit(0);
- }
- if (!system("su - user -c 'mount " MOUNTDIR "'"))
- wait_for_umount(MOUNTDIR "/.");
- xs_write(xs, XBT_NULL, "device/qpen", "umount", 6);
- xs_daemon_close(xs);
- return 0;
- }
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