u-tools/apps/busybox/procps/fuser.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * tiny fuser implementation
   4  *
   5  * Copyright 2004 Tony J. White
   6  *
   7  * May be distributed under the conditions of the
   8  * GNU Library General Public License
   9  */
  10
  11 #include "libbb.h"
  12
  13 #define MAX_LINE 255
  14
  15 #define OPTION_STRING "mks64"
  16 enum {
  17         OPT_MOUNT  = (1 << 0),
  18         OPT_KILL   = (1 << 1),
  19         OPT_SILENT = (1 << 2),
  20         OPT_IP6    = (1 << 3),
  21         OPT_IP4    = (1 << 4),
  22 };
  23
  24 typedef struct inode_list {
  25         struct inode_list *next;
  26         ino_t inode;
  27         dev_t dev;
  28 } inode_list;
  29
  30 typedef struct pid_list {
  31         struct pid_list *next;
  32         pid_t pid;
  33 } pid_list;
  34
  35 static dev_t find_socket_dev(void)
  36 {
  37         int fd = socket(AF_INET, SOCK_DGRAM, 0);
  38         if (fd >= 0) {
  39                 struct stat buf;
  40                 int r = fstat(fd, &buf);
  41                 close(fd);
  42                 if (r == 0)
  43                         return buf.st_dev;
  44         }
  45         return 0;
  46 }
  47
  48 static int file_to_dev_inode(const char *filename, dev_t *dev, ino_t *inode)
  49 {
  50         struct stat f_stat;
  51         if (stat(filename, &f_stat))
  52                 return 0;
  53         *inode = f_stat.st_ino;
  54         *dev = f_stat.st_dev;
  55         return 1;
  56 }
  57
  58 static char *parse_net_arg(const char *arg, unsigned *port)
  59 {
  60         char path[20], tproto[5];
  61
  62         if (sscanf(arg, "%u/%4s", port, tproto) != 2)
  63                 return NULL;
  64         sprintf(path, "/proc/net/%s", tproto);
  65         if (access(path, R_OK) != 0)
  66                 return NULL;
  67         return xstrdup(tproto);
  68 }
  69
  70 static pid_list *add_pid(pid_list *plist, pid_t pid)
  71 {
  72         pid_list *curr = plist;
  73         while (curr != NULL) {
  74                 if (curr->pid == pid)
  75                         return plist;
  76                 curr = curr->next;
  77         }
  78         curr = xmalloc(sizeof(pid_list));
  79         curr->pid = pid;
  80         curr->next = plist;
  81         return curr;
  82 }
  83
  84 static inode_list *add_inode(inode_list *ilist, dev_t dev, ino_t inode)
  85 {
  86         inode_list *curr = ilist;
  87         while (curr != NULL) {
  88                 if (curr->inode == inode && curr->dev == dev)
  89                         return ilist;
  90                 curr = curr->next;
  91         }
  92         curr = xmalloc(sizeof(inode_list));
  93         curr->dev = dev;
  94         curr->inode = inode;
  95         curr->next = ilist;
  96         return curr;
  97 }
  98
  99 static inode_list *scan_proc_net(const char *proto,
 100                                 unsigned port, inode_list *ilist)
 101 {
 102         char path[20], line[MAX_LINE + 1];
 103         ino_t tmp_inode;
 104         dev_t tmp_dev;
 105         long long uint64_inode;
 106         unsigned tmp_port;
 107         FILE *f;
 108
 109         tmp_dev = find_socket_dev();
 110
 111         sprintf(path, "/proc/net/%s", proto);
 112         f = fopen_for_read(path);
 113         if (!f)
 114                 return ilist;
 115
 116         while (fgets(line, MAX_LINE, f)) {
 117                 char addr[68];
 118                 if (sscanf(line, "%*d: %64[0-9A-Fa-f]:%x %*x:%*x %*x %*x:%*x "
 119                                 "%*x:%*x %*x %*d %*d %llu",
 120                                 addr, &tmp_port, &uint64_inode) == 3
 121                 ) {
 122                         int len = strlen(addr);
 123                         if (len == 8 && (option_mask32 & OPT_IP6))
 124                                 continue;
 125                         if (len > 8 && (option_mask32 & OPT_IP4))
 126                                 continue;
 127                         if (tmp_port == port) {
 128                                 tmp_inode = uint64_inode;
 129                                 ilist = add_inode(ilist, tmp_dev, tmp_inode);
 130                         }
 131                 }
 132         }
 133         fclose(f);
 134         return ilist;
 135 }
 136
 137 static int search_dev_inode(inode_list *ilist, dev_t dev, ino_t inode)
 138 {
 139         while (ilist) {
 140                 if (ilist->dev == dev) {
 141                         if (option_mask32 & OPT_MOUNT)
 142                                 return 1;
 143                         if (ilist->inode == inode)
 144                                 return 1;
 145                 }
 146                 ilist = ilist->next;
 147         }
 148         return 0;
 149 }
 150
 151 static pid_list *scan_pid_maps(const char *fname, pid_t pid,
 152                                 inode_list *ilist, pid_list *plist)
 153 {
 154         FILE *file;
 155         char line[MAX_LINE + 1];
 156         int major, minor;
 157         ino_t inode;
 158         long long uint64_inode;
 159         dev_t dev;
 160
 161         file = fopen_for_read(fname);
 162         if (!file)
 163                 return plist;
 164         while (fgets(line, MAX_LINE, file)) {
 165                 if (sscanf(line, "%*s %*s %*s %x:%x %llu", &major, &minor, &uint64_inode) != 3)
 166                         continue;
 167                 inode = uint64_inode;
 168                 if (major == 0 && minor == 0 && inode == 0)
 169                         continue;
 170                 dev = makedev(major, minor);
 171                 if (search_dev_inode(ilist, dev, inode))
 172                         plist = add_pid(plist, pid);
 173         }
 174         fclose(file);
 175         return plist;
 176 }
 177
 178 static pid_list *scan_link(const char *lname, pid_t pid,
 179                                 inode_list *ilist, pid_list *plist)
 180 {
 181         ino_t inode;
 182         dev_t dev;
 183
 184         if (!file_to_dev_inode(lname, &dev, &inode))
 185                 return plist;
 186         if (search_dev_inode(ilist, dev, inode))
 187                 plist = add_pid(plist, pid);
 188         return plist;
 189 }
 190
 191 static pid_list *scan_dir_links(const char *dname, pid_t pid,
 192                                 inode_list *ilist, pid_list *plist)
 193 {
 194         DIR *d;
 195         struct dirent *de;
 196         char *lname;
 197
 198         d = opendir(dname);
 199         if (!d)
 200                 return plist;
 201         while ((de = readdir(d)) != NULL) {
 202                 lname = concat_subpath_file(dname, de->d_name);
 203                 if (lname == NULL)
 204                         continue;
 205                 plist = scan_link(lname, pid, ilist, plist);
 206                 free(lname);
 207         }
 208         closedir(d);
 209         return plist;
 210 }
 211
 212 /* NB: does chdir internally */
 213 static pid_list *scan_proc_pids(inode_list *ilist)
 214 {
 215         DIR *d;
 216         struct dirent *de;
 217         pid_t pid;
 218         pid_list *plist;
 219
 220         xchdir("/proc");
 221         d = opendir("/proc");
 222         if (!d)
 223                 return NULL;
 224
 225         plist = NULL;
 226         while ((de = readdir(d)) != NULL) {
 227                 pid = (pid_t)bb_strtou(de->d_name, NULL, 10);
 228                 if (errno)
 229                         continue;
 230                 if (chdir(de->d_name) < 0)
 231                         continue;
 232                 plist = scan_link("cwd", pid, ilist, plist);
 233                 plist = scan_link("exe", pid, ilist, plist);
 234                 plist = scan_link("root", pid, ilist, plist);
 235                 plist = scan_dir_links("fd", pid, ilist, plist);
 236                 plist = scan_dir_links("lib", pid, ilist, plist);
 237                 plist = scan_dir_links("mmap", pid, ilist, plist);
 238                 plist = scan_pid_maps("maps", pid, ilist, plist);
 239                 xchdir("/proc");
 240         }
 241         closedir(d);
 242         return plist;
 243 }
 244
 245 static int print_pid_list(pid_list *plist)
 246 {
 247         while (plist != NULL) {
 248                 printf("%u ", (unsigned)plist->pid);
 249                 plist = plist->next;
 250         }
 251         bb_putchar('\n');
 252         return 1;
 253 }
 254
 255 static int kill_pid_list(pid_list *plist, int sig)
 256 {
 257         pid_t mypid = getpid();
 258         int success = 1;
 259
 260         while (plist != NULL) {
 261                 if (plist->pid != mypid) {
 262                         if (kill(plist->pid, sig) != 0) {
 263                                 bb_perror_msg("kill pid %u", (unsigned)plist->pid);
 264                                 success = 0;
 265                         }
 266                 }
 267                 plist = plist->next;
 268         }
 269         return success;
 270 }
 271
 272 int fuser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 273 int fuser_main(int argc UNUSED_PARAM, char **argv)
 274 {
 275         pid_list *plist;
 276         inode_list *ilist;
 277         char **pp;
 278         dev_t dev;
 279         ino_t inode;
 280         unsigned port;
 281         int opt;
 282         int success;
 283         int killsig;
 284 /*
 285 fuser [options] FILEs or PORT/PROTOs
 286 Find processes which use FILEs or PORTs
 287         -m      Find processes which use same fs as FILEs
 288         -4      Search only IPv4 space
 289         -6      Search only IPv6 space
 290         -s      Silent: just exit with 0 if any processes are found
 291         -k      Kill found processes (otherwise display PIDs)
 292         -SIGNAL Signal to send (default: TERM)
 293 */
 294         /* Handle -SIGNAL. Oh my... */
 295         killsig = SIGTERM;
 296         pp = argv;
 297         while (*++pp) {
 298                 char *arg = *pp;
 299                 if (arg[0] != '-')
 300                         continue;
 301                 if (arg[1] == '-' && arg[2] == '\0') /* "--" */
 302                         break;
 303                 if ((arg[1] == '4' || arg[1] == '6') && arg[2] == '\0')
 304                         continue; /* it's "-4" or "-6" */
 305                 opt = get_signum(&arg[1]);
 306                 if (opt < 0)
 307                         continue;
 308                 /* "-SIGNAL" option found. Remove it and bail out */
 309                 killsig = opt;
 310                 do {
 311                         pp[0] = arg = pp[1];
 312                         pp++;
 313                 } while (arg);
 314                 break;
 315         }
 316
 317         opt = getopt32(argv, OPTION_STRING);
 318         argv += optind;
 319
 320         ilist = NULL;
 321         pp = argv;
 322         while (*pp) {
 323                 char *proto = parse_net_arg(*pp, &port);
 324                 if (proto) { /* PORT/PROTO */
 325                         ilist = scan_proc_net(proto, port, ilist);
 326                         free(proto);
 327                 } else { /* FILE */
 328                         if (!file_to_dev_inode(*pp, &dev, &inode))
 329                                 bb_perror_msg_and_die("can't open %s", *pp);
 330                         ilist = add_inode(ilist, dev, inode);
 331                 }
 332                 pp++;
 333         }
 334
 335         plist = scan_proc_pids(ilist); /* changes dir to "/proc" */
 336
 337         if (!plist)
 338                 return EXIT_FAILURE;
 339         success = 1;
 340         if (opt & OPT_KILL) {
 341                 success = kill_pid_list(plist, killsig);
 342         } else if (!(opt & OPT_SILENT)) {
 343                 success = print_pid_list(plist);
 344         }
 345         return (success != 1); /* 0 == success */
 346 }