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df36d82e3fc91bee2ff1681fd438c815fa324b6a
xen/tools/misc/xen-livepatch.c
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Ross Lagerwall ca01e58212 tools/livepatch: Exit with 2 if a timeout occurs 
Exit with 0 for success.
Exit with 1 for an error.
Exit with 2 if the operation should be retried for any reason (e.g. a
timeout or because another operation was in progress).

This allows a program or script driving xen-livepatch to determine if
the operation should be retried without parsing the output.

Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
2016-12-14 15:27:19 -05:00

526 lines
13 KiB
C
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/*
* Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
*/
#include <fcntl.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
#include <xenctrl.h>
#include <xenstore.h>
#include <xen/errno.h>
#include <xen-tools/libs.h>
static xc_interface *xch;
void show_help(void)
{
fprintf(stderr,
"xen-livepatch: live patching tool\n"
"Usage: xen-livepatch <command> [args]\n"
" <name> An unique name of payload. Up to %d characters.\n"
"Commands:\n"
" help display this help\n"
" upload <name> <file> upload file <file> with <name> name\n"
" list list payloads uploaded.\n"
" apply <name> apply <name> patch.\n"
" revert <name> revert name <name> patch.\n"
" replace <name> apply <name> patch and revert all others.\n"
" unload <name> unload name <name> patch.\n"
" load <file> upload and apply <file>.\n"
" name is the <file> name\n",
XEN_LIVEPATCH_NAME_SIZE);
}
/* wrapper function */
static int help_func(int argc, char *argv[])
{
show_help();
return 0;
}
#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
static const char *state2str(unsigned int state)
{
#define STATE(x) [LIVEPATCH_STATE_##x] = #x
static const char *const names[] = {
STATE(CHECKED),
STATE(APPLIED),
};
#undef STATE
if (state >= ARRAY_SIZE(names) || !names[state])
return "unknown";
return names[state];
}
/* This value was choosen adhoc. It could be 42 too. */
#define MAX_LEN 11
static int list_func(int argc, char *argv[])
{
unsigned int idx, done, left, i;
xen_livepatch_status_t *info = NULL;
char *name = NULL;
uint32_t *len = NULL;
int rc = ENOMEM;
if ( argc )
{
show_help();
return -1;
}
idx = left = 0;
info = malloc(sizeof(*info) * MAX_LEN);
if ( !info )
return rc;
name = malloc(sizeof(*name) * XEN_LIVEPATCH_NAME_SIZE * MAX_LEN);
if ( !name )
{
free(info);
return rc;
}
len = malloc(sizeof(*len) * MAX_LEN);
if ( !len ) {
free(name);
free(info);
return rc;
}
do {
done = 0;
/* The memset is done to catch errors. */
memset(info, 'A', sizeof(*info) * MAX_LEN);
memset(name, 'B', sizeof(*name) * MAX_LEN * XEN_LIVEPATCH_NAME_SIZE);
memset(len, 'C', sizeof(*len) * MAX_LEN);
rc = xc_livepatch_list(xch, MAX_LEN, idx, info, name, len, &done, &left);
if ( rc )
{
rc = errno;
fprintf(stderr, "Failed to list %d/%d.\n"
"Error %d: %s\n",
idx, left, rc, strerror(rc));
break;
}
if ( !idx )
fprintf(stdout," ID | status\n"
"----------------------------------------+------------\n");
for ( i = 0; i < done; i++ )
{
unsigned int j;
uint32_t sz;
char *str;
sz = len[i];
str = name + (i * XEN_LIVEPATCH_NAME_SIZE);
for ( j = sz; j < XEN_LIVEPATCH_NAME_SIZE; j++ )
str[j] = '\0';
printf("%-40s| %s", str, state2str(info[i].state));
if ( info[i].rc )
printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc));
else
puts("");
}
idx += done;
} while ( left );
free(name);
free(info);
free(len);
return rc;
}
#undef MAX_LEN
static int get_name(int argc, char *argv[], char *name)
{
ssize_t len = strlen(argv[0]);
if ( len > XEN_LIVEPATCH_NAME_SIZE )
{
fprintf(stderr, "ID must be no more than %d characters.\n",
XEN_LIVEPATCH_NAME_SIZE);
errno = EINVAL;
return errno;
}
/* Don't want any funny strings from the stack. */
memset(name, 0, XEN_LIVEPATCH_NAME_SIZE);
strncpy(name, argv[0], len);
return 0;
}
static int upload_func(int argc, char *argv[])
{
char *filename;
char name[XEN_LIVEPATCH_NAME_SIZE];
int fd = 0, rc;
struct stat buf;
unsigned char *fbuf;
ssize_t len;
if ( argc != 2 )
{
show_help();
return -1;
}
if ( get_name(argc, argv, name) )
return EINVAL;
filename = argv[1];
fd = open(filename, O_RDONLY);
if ( fd < 0 )
{
int saved_errno = errno;
fprintf(stderr, "Could not open %s.\n"
"Error %d: %s\n",
filename, saved_errno, strerror(saved_errno));
return saved_errno;
}
if ( stat(filename, &buf) != 0 )
{
int saved_errno = errno;
fprintf(stderr, "Could not get size of %s.\n"
"Error %d: %s\n",
filename, saved_errno, strerror(saved_errno));
close(fd);
return saved_errno;
}
len = buf.st_size;
fbuf = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0);
if ( fbuf == MAP_FAILED )
{
int saved_errno = errno;
fprintf(stderr, "Could not map %s.\n"
"Error %d: %s\n",
filename, saved_errno, strerror(saved_errno));
close (fd);
return saved_errno;
}
printf("Uploading %s... ", filename);
rc = xc_livepatch_upload(xch, name, fbuf, len);
if ( rc )
{
rc = errno;
printf("failed\n");
fprintf(stderr, "Error %d: %s\n", rc, strerror(rc));
}
else
printf("completed\n");
if ( munmap( fbuf, len) )
{
fprintf(stderr, "Could not unmap %s.\n"
"Error %d: %s\n",
filename, errno, strerror(errno));
}
close(fd);
return rc;
}
/* These MUST match to the 'action_options[]' array slots. */
enum {
ACTION_APPLY = 0,
ACTION_REVERT = 1,
ACTION_UNLOAD = 2,
ACTION_REPLACE = 3,
};
struct {
int allow; /* State it must be in to call function. */
int expected; /* The state to be in after the function. */
const char *name;
const char *verb;
int (*function)(xc_interface *xch, char *name, uint32_t timeout);
} action_options[] = {
{ .allow = LIVEPATCH_STATE_CHECKED,
.expected = LIVEPATCH_STATE_APPLIED,
.name = "apply",
.verb = "Applying",
.function = xc_livepatch_apply,
},
{ .allow = LIVEPATCH_STATE_APPLIED,
.expected = LIVEPATCH_STATE_CHECKED,
.name = "revert",
.verb = "Reverting",
.function = xc_livepatch_revert,
},
{ .allow = LIVEPATCH_STATE_CHECKED,
.expected = -XEN_ENOENT,
.name = "unload",
.verb = "Unloading",
.function = xc_livepatch_unload,
},
{ .allow = LIVEPATCH_STATE_CHECKED,
.expected = LIVEPATCH_STATE_APPLIED,
.name = "replace",
.verb = "Replacing all live patches with",
.function = xc_livepatch_replace,
},
};
/* The hypervisor timeout for the live patching operation is 30 msec,
* but it could take some time for the operation to start, so wait twice
* that period. */
#define HYPERVISOR_TIMEOUT_NS 30000000
#define DELAY (2 * HYPERVISOR_TIMEOUT_NS)
static void nanosleep_retry(long ns)
{
struct timespec req, rem;
int rc;
rem.tv_sec = 0;
rem.tv_nsec = ns;
do {
req = rem;
rc = nanosleep(&req, &rem);
} while ( rc == -1 && errno == EINTR );
}
int action_func(int argc, char *argv[], unsigned int idx)
{
char name[XEN_LIVEPATCH_NAME_SIZE];
int rc;
xen_livepatch_status_t status;
if ( argc != 1 )
{
show_help();
return -1;
}
if ( idx >= ARRAY_SIZE(action_options) )
return -1;
if ( get_name(argc, argv, name) )
return EINVAL;
/* Check initial status. */
rc = xc_livepatch_get(xch, name, &status);
if ( rc )
{
int saved_errno = errno;
fprintf(stderr, "Failed to get status of %s.\n"
"Error %d: %s\n",
name, saved_errno, strerror(saved_errno));
return saved_errno;
}
if ( status.rc == -XEN_EAGAIN )
{
fprintf(stderr,
"Cannot execute %s.\n"
"Operation already in progress.\n", action_options[idx].name);
return EAGAIN;
}
if ( status.state == action_options[idx].expected )
{
printf("No action needed.\n");
return 0;
}
/* Perform action. */
if ( action_options[idx].allow & status.state )
{
printf("%s %s... ", action_options[idx].verb, name);
rc = action_options[idx].function(xch, name, HYPERVISOR_TIMEOUT_NS);
if ( rc )
{
int saved_errno = errno;
printf("failed\n");
fprintf(stderr, "Error %d: %s\n",
saved_errno, strerror(saved_errno));
return saved_errno;
}
}
else
{
fprintf(stderr, "%s is in the wrong state.\n"
"Current state: %s\n"
"Expected state: %s\n",
name, state2str(status.state),
state2str(action_options[idx].allow));
return -1;
}
nanosleep_retry(DELAY);
rc = xc_livepatch_get(xch, name, &status);
if ( rc )
rc = -errno;
else if ( status.rc )
rc = status.rc;
if ( rc == -XEN_EAGAIN )
{
printf("failed\n");
fprintf(stderr, "Operation didn't complete.\n");
return EAGAIN;
}
if ( rc == 0 )
rc = status.state;
if ( action_options[idx].expected == rc )
printf("completed\n");
else if ( rc < 0 )
{
printf("failed\n");
fprintf(stderr, "Error %d: %s\n", -rc, strerror(-rc));
return -rc;
}
else
{
printf("failed\n");
fprintf(stderr, "%s is in the wrong state.\n"
"Current state: %s\n"
"Expected state: %s\n",
name, state2str(rc),
state2str(action_options[idx].expected));
return -1;
}
return 0;
}
static int load_func(int argc, char *argv[])
{
int rc;
char *new_argv[2];
char *path, *name, *lastdot;
if ( argc != 1 )
{
show_help();
return -1;
}
/* <file> */
new_argv[1] = argv[0];
/* Synthesize the <id> */
path = strdup(argv[0]);
name = basename(path);
lastdot = strrchr(name, '.');
if ( lastdot != NULL )
*lastdot = '\0';
new_argv[0] = name;
rc = upload_func(2 /* <id> <file> */, new_argv);
if ( rc )
return rc;
rc = action_func(1 /* only <id> */, new_argv, ACTION_APPLY);
if ( rc )
action_func(1, new_argv, ACTION_UNLOAD);
free(path);
return rc;
}
/*
* These are also functions in action_options that are called in case
* none of the ones in main_options match.
*/
struct {
const char *name;
int (*function)(int argc, char *argv[]);
} main_options[] = {
{ "help", help_func },
{ "list", list_func },
{ "upload", upload_func },
{ "load", load_func },
};
int main(int argc, char *argv[])
{
int i, j = 0, ret;
/*
* Set stdout to be unbuffered to avoid having to fflush when
* printing without a newline.
*/
setvbuf(stdout, NULL, _IONBF, 0);
if ( argc <= 1 )
{
show_help();
return 0;
}
for ( i = 0; i < ARRAY_SIZE(main_options); i++ )
if (!strncmp(main_options[i].name, argv[1], strlen(argv[1])))
break;
if ( i == ARRAY_SIZE(main_options) )
{
for ( j = 0; j < ARRAY_SIZE(action_options); j++ )
if (!strncmp(action_options[j].name, argv[1], strlen(argv[1])))
break;
if ( j == ARRAY_SIZE(action_options) )
{
fprintf(stderr, "Unrecognised command '%s' -- try "
"'xen-livepatch help'\n", argv[1]);
return 1;
}
}
xch = xc_interface_open(0,0,0);
if ( !xch )
{
fprintf(stderr, "failed to get the handler\n");
return 0;
}
if ( i == ARRAY_SIZE(main_options) )
ret = action_func(argc -2, argv + 2, j);
else
ret = main_options[i].function(argc -2, argv + 2);
xc_interface_close(xch);
/*
* Exitcode 0 for success.
* Exitcode 1 for an error.
* Exitcode 2 if the operation should be retried for any reason (e.g. a
* timeout or because another operation was in progress).
*/
#define EXIT_TIMEOUT (EXIT_FAILURE + 1)
BUILD_BUG_ON(EXIT_SUCCESS != 0);
BUILD_BUG_ON(EXIT_FAILURE != 1);
BUILD_BUG_ON(EXIT_TIMEOUT != 2);
switch ( ret )
{
case 0:
return EXIT_SUCCESS;
case EAGAIN:
case EBUSY:
return EXIT_TIMEOUT;
default:
return EXIT_FAILURE;
}
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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