text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at https://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  #include "test.h"
  
  #ifdef HAVE_SYS_RESOURCE_H
  #include <sys/resource.h>
  #endif
  #ifdef HAVE_FCNTL_H
  #include <fcntl.h>
  #endif
  #include <limits.h>
  
  #include "warnless.h"
  #include "memdebug.h"
  
  #ifndef FD_SETSIZE
  #error "this test requires FD_SETSIZE"
  #endif
  
  #define SAFETY_MARGIN (16)
  #define NUM_OPEN      (FD_SETSIZE + 10)
  #define NUM_NEEDED    (NUM_OPEN + SAFETY_MARGIN)
  
  #if defined(WIN32) || defined(_WIN32) || defined(MSDOS)
  #define DEV_NULL "NUL"
  #else
  #define DEV_NULL "/dev/null"
  #endif
  
  #if defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT)
  
  static int *fd = NULL;
  static struct rlimit num_open;
  static char msgbuff[256];
  
  static void store_errmsg(const char *msg, int err)
  {
    if(!err)
      snprintf(msgbuff, sizeof(msgbuff), "%s", msg);
    else
      snprintf(msgbuff, sizeof(msgbuff), "%s, errno %d, %s", msg,
               err, strerror(err));
  }
  
  static void close_file_descriptors(void)
  {
    for(num_open.rlim_cur = 0;
        num_open.rlim_cur < num_open.rlim_max;
        num_open.rlim_cur++)
      if(fd[num_open.rlim_cur] > 0)
        close(fd[num_open.rlim_cur]);
    free(fd);
    fd = NULL;
  }
  
  static int fopen_works(void)
  {
    FILE *fpa[3];
    int i;
    int ret = 1;
  
    for(i = 0; i < 3; i++) {
      fpa[i] = NULL;
    }
    for(i = 0; i < 3; i++) {
      fpa[i] = fopen(DEV_NULL, FOPEN_READTEXT);
      if(fpa[i] == NULL) {
        store_errmsg("fopen failed", errno);
        fprintf(stderr, "%s\n", msgbuff);
        ret = 0;
        break;
      }
    }
    for(i = 0; i < 3; i++) {
      if(fpa[i] != NULL)
        fclose(fpa[i]);
    }
    return ret;
  }
  
  static int rlimit(int keep_open)
  {
    int nitems, i;
    int *memchunk = NULL;
    char *fmt;
    struct rlimit rl;
    char strbuff[256];
    char strbuff1[81];
    char strbuff2[81];
    char fmt_u[] = "%u";
    char fmt_lu[] = "%lu";
  #ifdef HAVE_LONGLONG
    char fmt_llu[] = "%llu";
  
    if(sizeof(rl.rlim_max) > sizeof(long))
      fmt = fmt_llu;
    else
  #endif
      fmt = (sizeof(rl.rlim_max) < sizeof(long))?fmt_u:fmt_lu;
  
    /* get initial open file limits */
  
    if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
      store_errmsg("getrlimit() failed", errno);
      fprintf(stderr, "%s\n", msgbuff);
      return -1;
    }
  
    /* show initial open file limits */
  
  #ifdef RLIM_INFINITY
    if(rl.rlim_cur == RLIM_INFINITY)
      strcpy(strbuff, "INFINITY");
    else
  #endif
      snprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
    fprintf(stderr, "initial soft limit: %s\n", strbuff);
  
  #ifdef RLIM_INFINITY
    if(rl.rlim_max == RLIM_INFINITY)
      strcpy(strbuff, "INFINITY");
    else
  #endif
      snprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_max);
    fprintf(stderr, "initial hard limit: %s\n", strbuff);
  
    /* show our constants */
  
    fprintf(stderr, "test518 FD_SETSIZE: %d\n", FD_SETSIZE);
    fprintf(stderr, "test518 NUM_OPEN  : %d\n", NUM_OPEN);
    fprintf(stderr, "test518 NUM_NEEDED: %d\n", NUM_NEEDED);
  
    /*
     * if soft limit and hard limit are different we ask the
     * system to raise soft limit all the way up to the hard
     * limit. Due to some other system limit the soft limit
     * might not be raised up to the hard limit. So from this
     * point the resulting soft limit is our limit. Trying to
     * open more than soft limit file descriptors will fail.
     */
  
    if(rl.rlim_cur != rl.rlim_max) {
  
  #ifdef OPEN_MAX
      if((rl.rlim_cur > 0) &&
         (rl.rlim_cur < OPEN_MAX)) {
        fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
        rl.rlim_cur = OPEN_MAX;
        if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
          /* on failure don't abort just issue a warning */
          store_errmsg("setrlimit() failed", errno);
          fprintf(stderr, "%s\n", msgbuff);
          msgbuff[0] = '\0';
        }
      }
  #endif
  
      fprintf(stderr, "raising soft limit up to hard limit\n");
      rl.rlim_cur = rl.rlim_max;
      if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
        /* on failure don't abort just issue a warning */
        store_errmsg("setrlimit() failed", errno);
        fprintf(stderr, "%s\n", msgbuff);
        msgbuff[0] = '\0';
      }
  
      /* get current open file limits */
  
      if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
        store_errmsg("getrlimit() failed", errno);
        fprintf(stderr, "%s\n", msgbuff);
        return -3;
      }
  
      /* show current open file limits */
  
  #ifdef RLIM_INFINITY
      if(rl.rlim_cur == RLIM_INFINITY)
        strcpy(strbuff, "INFINITY");
      else
  #endif
        snprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
      fprintf(stderr, "current soft limit: %s\n", strbuff);
  
  #ifdef RLIM_INFINITY
      if(rl.rlim_max == RLIM_INFINITY)
        strcpy(strbuff, "INFINITY");
      else
  #endif
        snprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_max);
      fprintf(stderr, "current hard limit: %s\n", strbuff);
  
    } /* (rl.rlim_cur != rl.rlim_max) */
  
    /*
     * test 518 is all about testing libcurl functionality
     * when more than FD_SETSIZE file descriptors are open.
     * This means that if for any reason we are not able to
     * open more than FD_SETSIZE file descriptors then test
     * 518 should not be run.
     */
  
    /*
     * verify that soft limit is higher than NUM_NEEDED,
     * which is the number of file descriptors we would
     * try to open plus SAFETY_MARGIN to not exhaust the
     * file descriptor pool
     */
  
    num_open.rlim_cur = NUM_NEEDED;
  
    if((rl.rlim_cur > 0) &&
  #ifdef RLIM_INFINITY
       (rl.rlim_cur != RLIM_INFINITY) &&
  #endif
       (rl.rlim_cur <= num_open.rlim_cur)) {
      snprintf(strbuff2, sizeof(strbuff2), fmt, rl.rlim_cur);
      snprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
      snprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
               strbuff1, strbuff2);
      store_errmsg(strbuff, 0);
      fprintf(stderr, "%s\n", msgbuff);
      return -4;
    }
  
    /*
     * reserve a chunk of memory before opening file descriptors to
     * avoid a low memory condition once the file descriptors are
     * open. System conditions that could make the test fail should
     * be addressed in the precheck phase. This chunk of memory shall
     * be always free()ed before exiting the rlimit() function so
     * that it becomes available to the test.
     */
  
    for(nitems = i = 1; nitems <= i; i *= 2)
      nitems = i;
    if(nitems > 0x7fff)
      nitems = 0x40000;
    do {
      num_open.rlim_max = sizeof(*memchunk) * (size_t)nitems;
      snprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
      fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
      memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
      if(!memchunk) {
        fprintf(stderr, "memchunk, malloc() failed\n");
        nitems /= 2;
      }
    } while(nitems && !memchunk);
    if(!memchunk) {
      store_errmsg("memchunk, malloc() failed", errno);
      fprintf(stderr, "%s\n", msgbuff);
      return -5;
    }
  
    /* initialize it to fight lazy allocation */
  
    fprintf(stderr, "initializing memchunk array\n");
  
    for(i = 0; i < nitems; i++)
      memchunk[i] = -1;
  
    /* set the number of file descriptors we will try to open */
  
    num_open.rlim_max = NUM_OPEN;
  
    /* verify that we won't overflow size_t in malloc() */
  
    if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*fd)) {
      snprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_max);
      snprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
               "file descriptors, would overflow size_t", strbuff1);
      store_errmsg(strbuff, 0);
      fprintf(stderr, "%s\n", msgbuff);
      free(memchunk);
      return -6;
    }
  
    /* allocate array for file descriptors */
  
    snprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
    fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
  
    fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
    if(!fd) {
      store_errmsg("fd, malloc() failed", errno);
      fprintf(stderr, "%s\n", msgbuff);
      free(memchunk);
      return -7;
    }
  
    /* initialize it to fight lazy allocation */
  
    fprintf(stderr, "initializing fd array\n");
  
    for(num_open.rlim_cur = 0;
        num_open.rlim_cur < num_open.rlim_max;
        num_open.rlim_cur++)
      fd[num_open.rlim_cur] = -1;
  
    snprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
    fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
  
    /* open a dummy descriptor */
  
    fd[0] = open(DEV_NULL, O_RDONLY);
    if(fd[0] < 0) {
      snprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
      store_errmsg(strbuff, errno);
      fprintf(stderr, "%s\n", msgbuff);
      free(fd);
      fd = NULL;
      free(memchunk);
      return -8;
    }
  
    /* create a bunch of file descriptors */
  
    for(num_open.rlim_cur = 1;
        num_open.rlim_cur < num_open.rlim_max;
        num_open.rlim_cur++) {
  
      fd[num_open.rlim_cur] = dup(fd[0]);
  
      if(fd[num_open.rlim_cur] < 0) {
  
        fd[num_open.rlim_cur] = -1;
  
        snprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
        snprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
        fprintf(stderr, "%s\n", strbuff);
  
        snprintf(strbuff1, sizeof(strbuff), fmt, num_open.rlim_cur);
        snprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
                 strbuff1);
        fprintf(stderr, "%s\n", strbuff);
  
        num_open.rlim_max = NUM_NEEDED;
  
        snprintf(strbuff2, sizeof(strbuff2), fmt, num_open.rlim_max);
        snprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
        snprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
                 strbuff2, strbuff1);
        store_errmsg(strbuff, 0);
        fprintf(stderr, "%s\n", msgbuff);
  
        for(num_open.rlim_cur = 0;
            fd[num_open.rlim_cur] >= 0;
            num_open.rlim_cur++)
          close(fd[num_open.rlim_cur]);
        free(fd);
        fd = NULL;
        free(memchunk);
        return -9;
  
      }
  
    }
  
    snprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
    fprintf(stderr, "%s file descriptors open\n", strbuff);
  
  #if !defined(HAVE_POLL_FINE)    && \
      !defined(USE_WINSOCK)       && \
      !defined(TPF)
  
    /*
     * when using select() instead of poll() we cannot test
     * libcurl functionality with a socket number equal or
     * greater than FD_SETSIZE. In any case, macro VERIFY_SOCK
     * in lib/select.c enforces this check and protects libcurl
     * from a possible crash. The effect of this protection
     * is that test 518 will always fail, since the actual
     * call to select() never takes place. We skip test 518
     * with an indication that select limit would be exceeded.
     */
  
    num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
    if(num_open.rlim_max > num_open.rlim_cur) {
      snprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
               FD_SETSIZE);
      store_errmsg(strbuff, 0);
      fprintf(stderr, "%s\n", msgbuff);
      close_file_descriptors();
      free(memchunk);
      return -10;
    }
  
    num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
    for(rl.rlim_cur = 0;
        rl.rlim_cur < num_open.rlim_max;
        rl.rlim_cur++) {
      if((fd[rl.rlim_cur] > 0) &&
         ((unsigned int)fd[rl.rlim_cur] > num_open.rlim_cur)) {
        snprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
                 FD_SETSIZE);
        store_errmsg(strbuff, 0);
        fprintf(stderr, "%s\n", msgbuff);
        close_file_descriptors();
        free(memchunk);
        return -11;
      }
    }
  
  #endif /* using a FD_SETSIZE bound select() */
  
    /*
     * Old or 'backwards compatible' implementations of stdio do not allow
     * handling of streams with an underlying file descriptor number greater
     * than 255, even when allowing high numbered file descriptors for sockets.
     * At this point we have a big number of file descriptors which have been
     * opened using dup(), so lets test the stdio implementation and discover
     * if it is capable of fopen()ing some additional files.
     */
  
    if(!fopen_works()) {
      snprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_max);
      snprintf(strbuff, sizeof(strbuff),
               "fopen fails with %s fds open()",
               strbuff1);
      fprintf(stderr, "%s\n", msgbuff);
      snprintf(strbuff, sizeof(strbuff),
               "fopen fails with lots of fds open()");
      store_errmsg(strbuff, 0);
      close_file_descriptors();
      free(memchunk);
      return -12;
    }
  
    /* free the chunk of memory we were reserving so that it
       becomes becomes available to the test */
  
    free(memchunk);
  
    /* close file descriptors unless instructed to keep them */
  
    if(!keep_open) {
      close_file_descriptors();
    }
  
    return 0;
  }
  
  int test(char *URL)
  {
    CURLcode res;
    CURL *curl;
  
    if(!strcmp(URL, "check")) {
      /* used by the test script to ask if we can run this test or not */
      if(rlimit(FALSE)) {
        fprintf(stdout, "rlimit problem: %s\n", msgbuff);
        return 1;
      }
      return 0; /* sure, run this! */
    }
  
    if(rlimit(TRUE)) {
      /* failure */
      return TEST_ERR_MAJOR_BAD;
    }
  
    /* run the test with the bunch of open file descriptors
       and close them all once the test is over */
  
    if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
      fprintf(stderr, "curl_global_init() failed\n");
      close_file_descriptors();
      return TEST_ERR_MAJOR_BAD;
    }
  
    curl = curl_easy_init();
    if(!curl) {
      fprintf(stderr, "curl_easy_init() failed\n");
      close_file_descriptors();
      curl_global_cleanup();
      return TEST_ERR_MAJOR_BAD;
    }
  
    test_setopt(curl, CURLOPT_URL, URL);
    test_setopt(curl, CURLOPT_HEADER, 1L);
  
    res = curl_easy_perform(curl);
  
  test_cleanup:
  
    close_file_descriptors();
    curl_easy_cleanup(curl);
    curl_global_cleanup();
  
    return (int)res;
  }
  
  #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
  
  int test(char *URL)
  {
    (void)URL;
    printf("system lacks necessary system function(s)");
    return 1; /* skip test */
  }
  
  #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
  