core-admin/dom0/restore/qubes_restore.c
2010-07-21 12:56:43 +02:00

420 lines
9.0 KiB
C

#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <signal.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <xs.h>
char xmlrpc_header[] =
"POST /RPC2 HTTP/1.0\r\n"
"Host: \r\n"
"User-Agent: xmlrpclib.py/1.0.1 (by www.pythonware.com)\r\n"
"Content-Type: text/xml\r\n" "Content-Length: %d\r\n" "\r\n";
char xmlrpc_body_restore[] =
"<?xml version='1.0'?>\n"
"<methodCall>\n"
"<methodName>xend.domain.restore</methodName>\n"
"<params>\n"
"<param>\n"
"<value><string>%s</string></value>\n"
"</param>\n"
"<param>\n"
"<value><boolean>0</boolean></value>\n"
"</param>\n" "</params>\n" "</methodCall>\n";
char xmlrpc_body_setmem[] =
"<?xml version='1.0'?>\n<methodCall>\n<methodName>xend.domain.setMemoryTarget</methodName>\n<params>\n<param>\n<value><string>%d</string></value>\n</param>\n<param>\n<value><int>%d</int></value>\n</param>\n</params>\n</methodCall>\n";
void send_raw(int fd, char *body)
{
char *header;
asprintf(&header, xmlrpc_header, strlen(body));
if (write(fd, header, strlen(header)) != strlen(header)) {
perror("write xend");
exit(1);
}
if (write(fd, body, strlen(body)) != strlen(body)) {
perror("write xend");
exit(1);
}
shutdown(fd, SHUT_WR);
}
void send_req_restore(int fd, char *name)
{
char *body;
asprintf(&body, xmlrpc_body_restore, name);
send_raw(fd, body);
}
void send_req_setmem(int fd, int domid, int mem)
{
char *body;
asprintf(&body, xmlrpc_body_setmem, domid, mem);
send_raw(fd, body);
}
char *recv_resp(int fd)
{
#define RESPSIZE 65536
static char buf[RESPSIZE];
int total = 0;
int n;
for (;;) {
n = read(fd, buf + total, RESPSIZE - total);
if (n == 0) {
buf[total] = 0;
close(fd);
return buf;
}
if (n < 0) {
perror("xend read");
exit(1);
}
total += n;
}
}
void bad_resp(char *resp)
{
fprintf(stderr, "Error; Xend response:\n%s\n", resp);
exit(1);
}
int parse_resp(char *resp)
{
char *domid;
if (strstr(resp, "<fault>"))
bad_resp(resp);
if (!strstr(resp, "domid"))
bad_resp(resp);
domid = strstr(resp, "<int>");
if (!domid)
bad_resp(resp);
return strtoul(domid + 5, NULL, 0);
}
char *gettime()
{
static char retbuf[60];
struct timeval tv;
gettimeofday(&tv, NULL);
snprintf(retbuf, sizeof(retbuf), "%lld.%lld",
(long long) tv.tv_sec, (long long) tv.tv_usec);
return retbuf;
}
int actually_do_unlink = 1;
#define FAST_FLAG_PATH "/var/run/qubes/fast_block_attach"
void set_fast_flag()
{
int fd = open(FAST_FLAG_PATH, O_CREAT | O_RDONLY, 0600);
if (fd < 0) {
perror("set_fast_flag");
exit(1);
}
close(fd);
}
void rm_fast_flag()
{
if (actually_do_unlink)
unlink(FAST_FLAG_PATH);
}
#define BUFSIZE (512*1024)
void do_read(int fd)
{
static char buf[BUFSIZE];
int n;
while ((n = read(fd, buf, BUFSIZE))) {
if (n < 0) {
perror("read savefile");
exit(1);
}
}
}
void preload_cache(int fd)
{
signal(SIGCHLD, SIG_IGN);
switch (fork()) {
case -1:
perror("fork");
exit(1);
case 0:
actually_do_unlink = 0;
do_read(fd);
fprintf(stderr, "time=%s, fs cache preload complete\n",
gettime());
exit(0);
default:
close(fd);
}
}
int xend_connect()
{
struct sockaddr_un server;
int s;
s = socket(AF_UNIX, SOCK_STREAM, 0);
if (s < 0) {
perror("socket af_unix");
exit(1);
}
server.sun_family = AF_UNIX;
strcpy(server.sun_path, "/var/run/xend/xmlrpc.sock");
if (connect
(s, (struct sockaddr *) &server,
strlen(server.sun_path) + sizeof(server.sun_family))) {
perror("connext xend");
exit(1);
}
return s;
}
void start_guid(int domid, int argc, char **argv)
{
char dstr[40];
snprintf(dstr, sizeof(dstr), "%d", domid);
if (argc == 2)
execl("/usr/bin/qubes_guid", "guid", "-d", dstr, "-c",
"red", "-i", "red", NULL);
else
execl("/usr/bin/qubes_guid", "guid", "-d", dstr, "-c",
"red", "-i", "red", "-e", argv[2], NULL);
perror("execl");
}
void fix_savefile(int fd, char *buf, char *pattern, char *val)
{
int i, len = strlen(val), origlen;
char *bracket;
char *loc = strstr(buf + 20, pattern) + strlen(pattern);
if (!loc)
return;
bracket = index(loc, ')');
if (!bracket)
return;
origlen = (long) bracket - (long) loc;
if (origlen < len) {
fprintf(stderr, "too long string %s\n", val);
exit(1);
}
for (i = 0; i < origlen - len; i++)
loc[i] = ' ';
memcpy(loc + i, val, strlen(val));
lseek(fd, (long) loc - (long) buf, SEEK_SET);
write(fd, loc, origlen);
}
#define NAME_PATTERN "/root-cow.img"
char *fix_savefile_and_get_vmname(int fd, int dispid)
{
static char buf[4096];
char *name;
char *slash;
char val[256];
if (read(fd, buf, sizeof(buf)) != sizeof(buf)) {
perror("read savefile");
exit(1);
}
buf[sizeof(buf) - 1] = 0;
snprintf(val, sizeof(val),
"064cd14c-95ad-4fc2-a4c9-cf9f522e5b%02x", dispid);
fix_savefile(fd, buf, "(uuid ", val);
snprintf(val, sizeof(val), "disp%02d", dispid);
fix_savefile(fd, buf, "(name ", val);
snprintf(val, sizeof(val), "00:16:3e:7c:8b:%02x", dispid);
fix_savefile(fd, buf, "(mac ", val);
lseek(fd, 0, SEEK_SET);
name = strstr(buf + 20, NAME_PATTERN);
if (!name) {
fprintf(stderr,
"cannot find 'root-cow.img' in savefile\n");
exit(1);
}
*name = 0;
slash = name - 1;
while (slash[0] && slash[0] != '/')
slash--;
if (!*slash) {
fprintf(stderr, "cannot find / in savefile\n");
exit(1);
}
return slash + 1;
}
void unpack_cows(char *name)
{
char vmdir[4096];
char tarfile[4096];
int status;
snprintf(vmdir, sizeof(vmdir), "/var/lib/qubes/appvms/%s", name);
snprintf(tarfile, sizeof(tarfile),
"/var/lib/qubes/appvms/%s/saved_cows.tar", name);
switch (fork()) {
case -1:
fprintf(stderr, "fork");
exit(1);
case 0:
execl("/bin/tar", "tar", "-C", vmdir, "-Sxf",
tarfile, NULL);
perror("execl");
exit(1);
default:
wait(&status);
if (WEXITSTATUS(status)) {
fprintf(stderr, "tar exited with status=0x%x\n",
status);
exit(1);
}
fprintf(stderr, "time=%s, cows restored\n", gettime());
}
}
void write_xs_single(struct xs_handle *xs, int domid, char *name,
char *val)
{
char key[256];
snprintf(key, sizeof(key), "/local/domain/%d/%s", domid, name);
if (!xs_write(xs, XBT_NULL, key, val, strlen(val))) {
fprintf(stderr, "xs_write");
exit(1);
}
}
void setup_xenstore(int domid, char *name)
{
char val[256];
char netvm_id_path[256];
int fd, n;
char netvm_id[256];
struct xs_handle *xs = xs_daemon_open();
if (!xs) {
perror("xs_daemon_open");
exit(1);
}
snprintf(netvm_id_path, sizeof(netvm_id_path),
"/var/lib/qubes/appvms/%s/netvm_id.txt", name);
fd = open(netvm_id_path, O_RDONLY);
if (fd < 0) {
perror("open netvm_id");
exit(1);
}
n = read(fd, netvm_id, sizeof(netvm_id) - 1);
close(fd);
netvm_id[n] = 0;
snprintf(val, sizeof(val), "10.%s.%d.%d", netvm_id,
domid / 254 + 200, (domid % 254) + 1);
write_xs_single(xs, domid, "qubes_ip", val);
write_xs_single(xs, domid, "qubes_netmask", "255.255.0.0");
snprintf(val, sizeof(val), "10.%s.0.1", netvm_id);
write_xs_single(xs, domid, "qubes_gateway", val);
snprintf(val, sizeof(val), "10.%s.255.254", netvm_id);
write_xs_single(xs, domid, "qubes_secondary_dns", val);
write_xs_single(xs, domid, "qubes_vm_type", "AppVM");
xs_daemon_close(xs);
}
int get_next_disposable_id()
{
int seq = 0;
int fd = open("/var/run/qubes/dispVM_seq", O_RDWR);
if (fd < 0) {
perror("open dispVM_seq");
exit(1);
}
read(fd, &seq, sizeof(seq));
seq++;
lseek(fd, 0, SEEK_SET);
write(fd, &seq, sizeof(seq));
close(fd);
return seq;
}
void write_varrun_domid(int domid)
{
FILE *f = fopen("/var/run/qubes/dispVM_xid", "w");
if (!f) {
perror("fopen dispVM_xid");
exit(1);
}
fprintf(f, "%d", domid);
fclose(f);
}
void redirect_stderr()
{
int fd =
open("/var/run/qubes/qubes_restore.log", O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (fd < 0) {
syslog(LOG_DAEMON | LOG_ERR, "open dvm.log");
exit(1);
}
dup2(fd, 2);
}
int main(int argc, char **argv)
{
int fd, domid, dispid;
char *resp;
char *name;
if (argc != 2 && argc != 3) {
fprintf(stderr, "usage: %s savefile [cmd] \n", argv[0]);
exit(1);
}
redirect_stderr();
fprintf(stderr, "time=%s, starting\n", gettime());
set_fast_flag();
atexit(rm_fast_flag);
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("open savefile");
exit(1);
}
dispid = get_next_disposable_id();
name = fix_savefile_and_get_vmname(fd, dispid);
// printf("name=%s\n", name);
unpack_cows(name);
// no preloading for now, assume savefile in shm
// preload_cache(fd);
fd = xend_connect();
send_req_restore(fd, argv[1]);
resp = recv_resp(fd);
domid = parse_resp(resp);
write_varrun_domid(domid);
fprintf(stderr,
"time=%s, created domid=%d, executing set_mem 400\n",
gettime(), domid);
fd = xend_connect();
send_req_setmem(fd, domid, 400);
resp = recv_resp(fd);
// printf("%s\n", resp);
fprintf(stderr, "time=%s, creating xenstore entries\n", gettime());
setup_xenstore(domid, name);
fprintf(stderr, "time=%s, starting qubes_guid\n", gettime());
rm_fast_flag();
start_guid(domid, argc, argv);
return 0;
}