1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273
|
/* guestfish - the filesystem interactive shell
* Copyright (C) 2011 Red Hat Inc.
*
* 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 <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
#include <libintl.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <guestfs.h>
#include "hash.h"
#include "hash-pjw.h"
#include "fish.h"
/* The hash table maps names to multiple (linked list of) event handlers. */
static Hash_table *event_handlers;
struct entry {
struct entry *next; /* Next entry in linked list. */
char *name; /* Event name. */
char *command; /* Shell script / command that runs. */
uint64_t event_bitmask; /* Events this is registered for. */
int eh; /* Event handle (from guestfs_set_event_callback). */
};
static void
entry_free (void *x)
{
if (x) {
struct entry *p = x;
entry_free (p->next);
free (p->name);
free (p->command);
free (p);
}
}
static size_t
entry_hash (void const *x, size_t table_size)
{
struct entry const *p = x;
return hash_pjw (p->name, table_size);
}
static bool
entry_compare (void const *x, void const *y)
{
struct entry const *p = x;
struct entry const *q = y;
return STREQ (p->name, q->name);
}
void
init_event_handlers (void)
{
assert (event_handlers == NULL);
event_handlers =
hash_initialize (64, NULL, entry_hash, entry_compare, entry_free);
}
void
free_event_handlers (void)
{
assert (event_handlers != NULL);
hash_free (event_handlers);
event_handlers = NULL;
}
static void
do_event_handler (guestfs_h *g,
void *opaque,
uint64_t event,
int event_handle,
int flags,
const char *buf, size_t buf_len,
const uint64_t *array, size_t array_len)
{
pid_t pid;
const char *argv[8 + array_len];
const char *shell;
struct entry *entry = opaque;
size_t i, j;
char *s;
pid = fork ();
if (pid == -1) {
perror ("event handler: fork");
return;
}
if (pid == 0) { /* Child process. */
shell = getenv ("SHELL");
if (!shell)
shell = "/bin/sh";
setenv ("EVENT", event_name_of_event_bitmask (event), 1);
/* Construct the command and arguments. */
i = 0;
argv[i++] = shell;
argv[i++] = "-c";
argv[i++] = entry->command;
argv[i++] = ""; /* $0 */
if (buf != NULL)
/* XXX: So far, buf is always ASCII NUL-terminated. There is no
* way to pass arbitrary 8 bit buffers.
*/
argv[i++] = buf;
for (j = 0; j < array_len; ++j) {
if (asprintf (&s, "%" PRIu64, array[j]) == -1) {
perror ("event handler: asprintf");
_exit (EXIT_FAILURE);
}
argv[i++] = s;
}
argv[i++] = NULL;
execvp (argv[0], (void *) argv);
perror (argv[0]);
_exit (EXIT_FAILURE);
}
if (waitpid (pid, NULL, 0) == -1)
perror ("event handler: waitpid");
}
int
run_event (const char *cmd, size_t argc, char *argv[])
{
int r;
struct entry *entry = NULL, *old_entry;
if (argc != 3) {
fprintf (stderr,
_("use 'event <name> <eventset> <script>' to register an event handler\n"));
goto error;
}
entry = calloc (1, sizeof *entry);
if (entry == NULL) {
perror ("calloc");
goto error;
}
entry->eh = -1;
r = event_bitmask_of_event_set (argv[1], &entry->event_bitmask);
if (r == -1)
goto error;
entry->name = strdup (argv[0]);
if (entry->name == NULL) {
perror ("strdup");
goto error;
}
entry->command = strdup (argv[2]);
if (entry->command == NULL) {
perror ("strdup");
goto error;
}
entry->eh =
guestfs_set_event_callback (g, do_event_handler,
entry->event_bitmask, 0, entry);
if (entry->eh == -1)
goto error;
r = hash_insert_if_absent (event_handlers, entry, (const void **) &old_entry);
if (r == -1)
goto error;
if (r == 0) { /* old_entry set to existing entry */
entry->next = old_entry->next;
/* XXX are we allowed to update the old entry? */
old_entry->next = entry;
}
return 0;
error:
if (entry) {
if (entry->eh >= 0)
guestfs_delete_event_callback (g, entry->eh);
free (entry->name);
free (entry->command);
free (entry);
}
return -1;
}
int
run_delete_event (const char *cmd, size_t argc, char *argv[])
{
if (argc != 1) {
fprintf (stderr,
_("use 'delete-event <name>' to delete an event handler\n"));
return -1;
}
const struct entry key = { .name = bad_cast (argv[0]) };
struct entry *entry, *p;
entry = hash_delete (event_handlers, &key);
if (!entry) {
fprintf (stderr, _("delete-event: %s: no such event handler\n"), argv[0]);
return -1;
}
/* Delete them from the handle. */
p = entry;
while (p) {
guestfs_delete_event_callback (g, p->eh);
p = p->next;
}
/* Free the structures. */
entry_free (entry);
return 0;
}
static bool
list_event (void *x, void *data)
{
struct entry *entry = x;
while (entry) {
printf ("\"%s\" (%d): ", entry->name, entry->eh);
print_event_set (entry->event_bitmask, stdout);
printf (": %s\n", entry->command);
entry = entry->next;
}
return 1;
}
int
run_list_events (const char *cmd, size_t argc, char *argv[])
{
if (argc != 0) {
fprintf (stderr,
_("use 'list-events' to list event handlers\n"));
return -1;
}
hash_do_for_each (event_handlers, list_event, NULL);
return 0;
}
|