1 /* Copyright libuv project contributors. All rights reserved.
2  *
3  * Permission is hereby granted, free of charge, to any person obtaining a copy
4  * of this software and associated documentation files (the "Software"), to
5  * deal in the Software without restriction, including without limitation the
6  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7  * sell copies of the Software, and to permit persons to whom the Software is
8  * furnished to do so, subject to the following conditions:
9  *
10  * The above copyright notice and this permission notice shall be included in
11  * all copies or substantial portions of the Software.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19  * IN THE SOFTWARE.
20  */
21 
22 
23 #include "os390-syscalls.h"
24 #include <errno.h>
25 #include <stdlib.h>
26 #include <search.h>
27 #include <termios.h>
28 #include <sys/msg.h>
29 
30 static QUEUE global_epoll_queue;
31 static uv_mutex_t global_epoll_lock;
32 static uv_once_t once = UV_ONCE_INIT;
33 
scandir(const char * maindir,struct dirent *** namelist,int (* filter)(const struct dirent *),int (* compar)(const struct dirent **,const struct dirent **))34 int scandir(const char* maindir, struct dirent*** namelist,
35             int (*filter)(const struct dirent*),
36             int (*compar)(const struct dirent**,
37             const struct dirent **)) {
38   struct dirent** nl;
39   struct dirent** nl_copy;
40   struct dirent* dirent;
41   unsigned count;
42   size_t allocated;
43   DIR* mdir;
44 
45   nl = NULL;
46   count = 0;
47   allocated = 0;
48   mdir = opendir(maindir);
49   if (!mdir)
50     return -1;
51 
52   for (;;) {
53     dirent = readdir(mdir);
54     if (!dirent)
55       break;
56     if (!filter || filter(dirent)) {
57       struct dirent* copy;
58       copy = uv__malloc(sizeof(*copy));
59       if (!copy)
60         goto error;
61       memcpy(copy, dirent, sizeof(*copy));
62 
63       nl_copy = uv__realloc(nl, sizeof(*copy) * (count + 1));
64       if (nl_copy == NULL) {
65         uv__free(copy);
66         goto error;
67       }
68 
69       nl = nl_copy;
70       nl[count++] = copy;
71     }
72   }
73 
74   qsort(nl, count, sizeof(struct dirent *),
75        (int (*)(const void *, const void *)) compar);
76 
77   closedir(mdir);
78 
79   *namelist = nl;
80   return count;
81 
82 error:
83   while (count > 0) {
84     dirent = nl[--count];
85     uv__free(dirent);
86   }
87   uv__free(nl);
88   closedir(mdir);
89   errno = ENOMEM;
90   return -1;
91 }
92 
93 
next_power_of_two(unsigned int val)94 static unsigned int next_power_of_two(unsigned int val) {
95   val -= 1;
96   val |= val >> 1;
97   val |= val >> 2;
98   val |= val >> 4;
99   val |= val >> 8;
100   val |= val >> 16;
101   val += 1;
102   return val;
103 }
104 
105 
maybe_resize(uv__os390_epoll * lst,unsigned int len)106 static void maybe_resize(uv__os390_epoll* lst, unsigned int len) {
107   unsigned int newsize;
108   unsigned int i;
109   struct pollfd* newlst;
110   struct pollfd event;
111 
112   if (len <= lst->size)
113     return;
114 
115   if (lst->size == 0)
116     event.fd = -1;
117   else {
118     /* Extract the message queue at the end. */
119     event = lst->items[lst->size - 1];
120     lst->items[lst->size - 1].fd = -1;
121   }
122 
123   newsize = next_power_of_two(len);
124   newlst = uv__reallocf(lst->items, newsize * sizeof(lst->items[0]));
125 
126   if (newlst == NULL)
127     abort();
128   for (i = lst->size; i < newsize; ++i)
129     newlst[i].fd = -1;
130 
131   /* Restore the message queue at the end */
132   newlst[newsize - 1] = event;
133 
134   lst->items = newlst;
135   lst->size = newsize;
136 }
137 
138 
init_message_queue(uv__os390_epoll * lst)139 static void init_message_queue(uv__os390_epoll* lst) {
140   struct {
141     long int header;
142     char body;
143   } msg;
144 
145   /* initialize message queue */
146   lst->msg_queue = msgget(IPC_PRIVATE, 0600 | IPC_CREAT);
147   if (lst->msg_queue == -1)
148     abort();
149 
150   /*
151      On z/OS, the message queue will be affiliated with the process only
152      when a send is performed on it. Once this is done, the system
153      can be queried for all message queues belonging to our process id.
154   */
155   msg.header = 1;
156   if (msgsnd(lst->msg_queue, &msg, sizeof(msg.body), 0) != 0)
157     abort();
158 
159   /* Clean up the dummy message sent above */
160   if (msgrcv(lst->msg_queue, &msg, sizeof(msg.body), 0, 0) != sizeof(msg.body))
161     abort();
162 }
163 
164 
before_fork(void)165 static void before_fork(void) {
166   uv_mutex_lock(&global_epoll_lock);
167 }
168 
169 
after_fork(void)170 static void after_fork(void) {
171   uv_mutex_unlock(&global_epoll_lock);
172 }
173 
174 
child_fork(void)175 static void child_fork(void) {
176   QUEUE* q;
177   uv_once_t child_once = UV_ONCE_INIT;
178 
179   /* reset once */
180   memcpy(&once, &child_once, sizeof(child_once));
181 
182   /* reset epoll list */
183   while (!QUEUE_EMPTY(&global_epoll_queue)) {
184     uv__os390_epoll* lst;
185     q = QUEUE_HEAD(&global_epoll_queue);
186     QUEUE_REMOVE(q);
187     lst = QUEUE_DATA(q, uv__os390_epoll, member);
188     uv__free(lst->items);
189     lst->items = NULL;
190     lst->size = 0;
191   }
192 
193   uv_mutex_unlock(&global_epoll_lock);
194   uv_mutex_destroy(&global_epoll_lock);
195 }
196 
197 
epoll_init(void)198 static void epoll_init(void) {
199   QUEUE_INIT(&global_epoll_queue);
200   if (uv_mutex_init(&global_epoll_lock))
201     abort();
202 
203   if (pthread_atfork(&before_fork, &after_fork, &child_fork))
204     abort();
205 }
206 
207 
epoll_create1(int flags)208 uv__os390_epoll* epoll_create1(int flags) {
209   uv__os390_epoll* lst;
210 
211   lst = uv__malloc(sizeof(*lst));
212   if (lst != NULL) {
213     /* initialize list */
214     lst->size = 0;
215     lst->items = NULL;
216     init_message_queue(lst);
217     maybe_resize(lst, 1);
218     lst->items[lst->size - 1].fd = lst->msg_queue;
219     lst->items[lst->size - 1].events = POLLIN;
220     lst->items[lst->size - 1].revents = 0;
221     uv_once(&once, epoll_init);
222     uv_mutex_lock(&global_epoll_lock);
223     QUEUE_INSERT_TAIL(&global_epoll_queue, &lst->member);
224     uv_mutex_unlock(&global_epoll_lock);
225   }
226 
227   return lst;
228 }
229 
230 
epoll_ctl(uv__os390_epoll * lst,int op,int fd,struct epoll_event * event)231 int epoll_ctl(uv__os390_epoll* lst,
232               int op,
233               int fd,
234               struct epoll_event *event) {
235   uv_mutex_lock(&global_epoll_lock);
236 
237   if (op == EPOLL_CTL_DEL) {
238     if (fd >= lst->size || lst->items[fd].fd == -1) {
239       uv_mutex_unlock(&global_epoll_lock);
240       errno = ENOENT;
241       return -1;
242     }
243     lst->items[fd].fd = -1;
244   } else if (op == EPOLL_CTL_ADD) {
245 
246     /* Resizing to 'fd + 1' would expand the list to contain at least
247      * 'fd'. But we need to guarantee that the last index on the list
248      * is reserved for the message queue. So specify 'fd + 2' instead.
249      */
250     maybe_resize(lst, fd + 2);
251     if (lst->items[fd].fd != -1) {
252       uv_mutex_unlock(&global_epoll_lock);
253       errno = EEXIST;
254       return -1;
255     }
256     lst->items[fd].fd = fd;
257     lst->items[fd].events = event->events;
258     lst->items[fd].revents = 0;
259   } else if (op == EPOLL_CTL_MOD) {
260     if (fd >= lst->size - 1 || lst->items[fd].fd == -1) {
261       uv_mutex_unlock(&global_epoll_lock);
262       errno = ENOENT;
263       return -1;
264     }
265     lst->items[fd].events = event->events;
266     lst->items[fd].revents = 0;
267   } else
268     abort();
269 
270   uv_mutex_unlock(&global_epoll_lock);
271   return 0;
272 }
273 
274 #define EP_MAX_PFDS (ULONG_MAX / sizeof(struct pollfd))
275 #define EP_MAX_EVENTS (INT_MAX / sizeof(struct epoll_event))
276 
epoll_wait(uv__os390_epoll * lst,struct epoll_event * events,int maxevents,int timeout)277 int epoll_wait(uv__os390_epoll* lst, struct epoll_event* events,
278                int maxevents, int timeout) {
279   nmsgsfds_t size;
280   struct pollfd* pfds;
281   int pollret;
282   int reventcount;
283   int nevents;
284   struct pollfd msg_fd;
285   int i;
286 
287   if (!lst || !lst->items || !events) {
288     errno = EFAULT;
289     return -1;
290   }
291 
292   if (lst->size > EP_MAX_PFDS) {
293     errno = EINVAL;
294     return -1;
295   }
296 
297   if (maxevents <= 0 || maxevents > EP_MAX_EVENTS) {
298     errno = EINVAL;
299     return -1;
300   }
301 
302   if (lst->size > 0)
303     _SET_FDS_MSGS(size, 1, lst->size - 1);
304   else
305     _SET_FDS_MSGS(size, 0, 0);
306   pfds = lst->items;
307   pollret = poll(pfds, size, timeout);
308   if (pollret <= 0)
309     return pollret;
310 
311   assert(lst->size > 0);
312 
313   pollret = _NFDS(pollret) + _NMSGS(pollret);
314 
315   reventcount = 0;
316   nevents = 0;
317   msg_fd = pfds[lst->size - 1];
318   for (i = 0;
319        i < lst->size && i < maxevents && reventcount < pollret; ++i) {
320     struct epoll_event ev;
321     struct pollfd* pfd;
322 
323     pfd = &pfds[i];
324     if (pfd->fd == -1 || pfd->revents == 0)
325       continue;
326 
327     ev.fd = pfd->fd;
328     ev.events = pfd->revents;
329     ev.is_msg = 0;
330     if (pfd->revents & POLLIN && pfd->revents & POLLOUT)
331       reventcount += 2;
332     else if (pfd->revents & (POLLIN | POLLOUT))
333       ++reventcount;
334 
335     pfd->revents = 0;
336     events[nevents++] = ev;
337   }
338 
339   if (msg_fd.revents != 0 && msg_fd.fd != -1)
340     if (i == lst->size)
341       events[nevents - 1].is_msg = 1;
342 
343   return nevents;
344 }
345 
346 
epoll_file_close(int fd)347 int epoll_file_close(int fd) {
348   QUEUE* q;
349 
350   uv_once(&once, epoll_init);
351   uv_mutex_lock(&global_epoll_lock);
352   QUEUE_FOREACH(q, &global_epoll_queue) {
353     uv__os390_epoll* lst;
354 
355     lst = QUEUE_DATA(q, uv__os390_epoll, member);
356     if (fd < lst->size && lst->items != NULL && lst->items[fd].fd != -1)
357       lst->items[fd].fd = -1;
358   }
359 
360   uv_mutex_unlock(&global_epoll_lock);
361   return 0;
362 }
363 
epoll_queue_close(uv__os390_epoll * lst)364 void epoll_queue_close(uv__os390_epoll* lst) {
365   /* Remove epoll instance from global queue */
366   uv_mutex_lock(&global_epoll_lock);
367   QUEUE_REMOVE(&lst->member);
368   uv_mutex_unlock(&global_epoll_lock);
369 
370   /* Free resources */
371   msgctl(lst->msg_queue, IPC_RMID, NULL);
372   lst->msg_queue = -1;
373   uv__free(lst->items);
374   lst->items = NULL;
375 }
376 
377 
mkdtemp(char * path)378 char* mkdtemp(char* path) {
379   static const char* tempchars =
380     "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
381   static const size_t num_chars = 62;
382   static const size_t num_x = 6;
383   char *ep, *cp;
384   unsigned int tries, i;
385   size_t len;
386   uint64_t v;
387   int fd;
388   int retval;
389   int saved_errno;
390 
391   len = strlen(path);
392   ep = path + len;
393   if (len < num_x || strncmp(ep - num_x, "XXXXXX", num_x)) {
394     errno = EINVAL;
395     return NULL;
396   }
397 
398   fd = open("/dev/urandom", O_RDONLY);
399   if (fd == -1)
400     return NULL;
401 
402   tries = TMP_MAX;
403   retval = -1;
404   do {
405     if (read(fd, &v, sizeof(v)) != sizeof(v))
406       break;
407 
408     cp = ep - num_x;
409     for (i = 0; i < num_x; i++) {
410       *cp++ = tempchars[v % num_chars];
411       v /= num_chars;
412     }
413 
414     if (mkdir(path, S_IRWXU) == 0) {
415       retval = 0;
416       break;
417     }
418     else if (errno != EEXIST)
419       break;
420   } while (--tries);
421 
422   saved_errno = errno;
423   uv__close(fd);
424   if (tries == 0) {
425     errno = EEXIST;
426     return NULL;
427   }
428 
429   if (retval == -1) {
430     errno = saved_errno;
431     return NULL;
432   }
433 
434   return path;
435 }
436 
437 
os390_readlink(const char * path,char * buf,size_t len)438 ssize_t os390_readlink(const char* path, char* buf, size_t len) {
439   ssize_t rlen;
440   ssize_t vlen;
441   ssize_t plen;
442   char* delimiter;
443   char old_delim;
444   char* tmpbuf;
445   char realpathstr[PATH_MAX + 1];
446 
447   tmpbuf = uv__malloc(len + 1);
448   if (tmpbuf == NULL) {
449     errno = ENOMEM;
450     return -1;
451   }
452 
453   rlen = readlink(path, tmpbuf, len);
454   if (rlen < 0) {
455     uv__free(tmpbuf);
456     return rlen;
457   }
458 
459   if (rlen < 3 || strncmp("/$", tmpbuf, 2) != 0) {
460     /* Straightforward readlink. */
461     memcpy(buf, tmpbuf, rlen);
462     uv__free(tmpbuf);
463     return rlen;
464   }
465 
466   /*
467    * There is a parmlib variable at the beginning
468    * which needs interpretation.
469    */
470   tmpbuf[rlen] = '\0';
471   delimiter = strchr(tmpbuf + 2, '/');
472   if (delimiter == NULL)
473     /* No slash at the end */
474     delimiter = strchr(tmpbuf + 2, '\0');
475 
476   /* Read real path of the variable. */
477   old_delim = *delimiter;
478   *delimiter = '\0';
479   if (realpath(tmpbuf, realpathstr) == NULL) {
480     uv__free(tmpbuf);
481     return -1;
482   }
483 
484   /* realpathstr is not guaranteed to end with null byte.*/
485   realpathstr[PATH_MAX] = '\0';
486 
487   /* Reset the delimiter and fill up the buffer. */
488   *delimiter = old_delim;
489   plen = strlen(delimiter);
490   vlen = strlen(realpathstr);
491   rlen = plen + vlen;
492   if (rlen > len) {
493     uv__free(tmpbuf);
494     errno = ENAMETOOLONG;
495     return -1;
496   }
497   memcpy(buf, realpathstr, vlen);
498   memcpy(buf + vlen, delimiter, plen);
499 
500   /* Done using temporary buffer. */
501   uv__free(tmpbuf);
502 
503   return rlen;
504 }
505 
506 
sem_init(UV_PLATFORM_SEM_T * semid,int pshared,unsigned int value)507 int sem_init(UV_PLATFORM_SEM_T* semid, int pshared, unsigned int value) {
508   UNREACHABLE();
509 }
510 
511 
sem_destroy(UV_PLATFORM_SEM_T * semid)512 int sem_destroy(UV_PLATFORM_SEM_T* semid) {
513   UNREACHABLE();
514 }
515 
516 
sem_post(UV_PLATFORM_SEM_T * semid)517 int sem_post(UV_PLATFORM_SEM_T* semid) {
518   UNREACHABLE();
519 }
520 
521 
sem_trywait(UV_PLATFORM_SEM_T * semid)522 int sem_trywait(UV_PLATFORM_SEM_T* semid) {
523   UNREACHABLE();
524 }
525 
526 
sem_wait(UV_PLATFORM_SEM_T * semid)527 int sem_wait(UV_PLATFORM_SEM_T* semid) {
528   UNREACHABLE();
529 }
530