Apache Module: mod_randomint

Small Apache module to generate random integers 
  1. #include "httpd.h"
  2. #include "http_config.h"
  3. #include "http_core.h"
  4. #include "http_log.h"
  5. #include "http_protocol.h"
  6.  
  7. #define MAX_COUNT 128
  8. #define DEFAULT_ENCTYPE "application/x-www-form-urlencoded"
  9.  
  10. static int chunk_reader(request_rec *r, const char **rbuf)
  11. {
  12.     int ret;
  13.  
  14.     if(OK != (ret = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR))) {
  15.         return ret;
  16.     }
  17.  
  18.     if(ap_should_client_block(r)) {
  19.         char argsbuffer[HUGE_STRING_LEN];
  20.         int rsize, len_read, rpos=0;
  21.         long length = r->remaining;
  22.  
  23.         *rbuf = apr_pcalloc(r->pool, length + 1);
  24.  
  25.         while(0 < (len_read = ap_get_client_block(r, argsbuffer, sizeof(argsbuffer)))) {
  26.             if ((rpos + len_read) > length) {
  27.                 rsize = length - rpos;
  28.             }
  29.             else {
  30.                 rsize = len_read;
  31.             }
  32.  
  33.             memcpy((char*)*rbuf + rpos, argsbuffer, rsize);
  34.             rpos += rsize;
  35.         }
  36.     }
  37.  
  38.     return ret;
  39. }
  40.  
  41. static int read_post(request_rec *r, apr_table_t **tab)
  42. {
  43.     const char *data;
  44.     const char *key, *val, *type;
  45.     int ret = OK;
  46.  
  47.     if(r->method_number != M_POST) {
  48.         return ret;
  49.     }
  50.  
  51.     type = apr_table_get(r->headers_in, "Content-Type");
  52.  
  53.     if(strcasecmp(type, DEFAULT_ENCTYPE) != 0) {
  54.         return DECLINED;
  55.     }
  56.  
  57.     if((ret = chunk_reader(r, &data)) != OK) {
  58.        return ret;
  59.     }
  60.  
  61.     if(*tab) {
  62.         apr_table_clear(*tab);
  63.     }
  64.     else {
  65.         *tab = apr_table_make(r->pool, 8);
  66.     }
  67.  
  68.     while(*data && (val = ap_getword(r->pool, &data, '&'))) {
  69.         key = ap_getword(r->pool, &val, '=');
  70.         ap_unescape_url((char*)key);
  71.         ap_unescape_url((char*)val);
  72.         apr_table_merge(*tab, key, val);
  73.     }
  74.  
  75.     return OK;
  76. }
  77.  
  78. int get_value(request_rec *r, const char *name)
  79. {
  80.     apr_table_t *post_values = NULL;
  81.     apr_array_header_t *arr;
  82.     apr_table_entry_t *elt;
  83.  
  84.     int i, ret, value;
  85.  
  86.     if(OK != (ret = read_post(r, &post_values))) {
  87.         return -1;
  88.     }
  89.  
  90.     if(NULL == post_values) {
  91.         return -1;
  92.     }
  93.  
  94.     arr = apr_table_elts(post_values);
  95.     elt = (apr_table_entry_t*)arr->elts;
  96.  
  97.     for(i = 0; i < arr->nelts; ++i) {
  98.         if(strcmp(elt[i].key, name) == 0
  99.         && LONG_MIN != (value = strtol(elt[i].val, NULL, 10))) {
  100.             return value;
  101.         }
  102.     }
  103.  
  104.     return -1;
  105. }
  106.  
  107. static int mod_randomint_method_handler (request_rec *r)
  108. {
  109.     int ret = OK, i, count = 8, new_count;
  110.     unsigned int random_value;
  111.  
  112.     if(strcmp(r->handler, "randomint-handler")) {
  113.         return DECLINED;
  114.     }
  115.  
  116.     new_count = get_value(r, "count");
  117.  
  118.     if(new_count > 0 && new_count < MAX_COUNT) {
  119.         count = new_count;
  120.     }
  121.  
  122.     ap_set_content_type(r, "text/plain");
  123.  
  124.     int random_fd = open("/dev/urandom", O_RDONLY);
  125.     for(i = 0; i < count; i ++) {
  126.         read(random_fd, (void*)&random_value, sizeof(random_value));
  127.         ap_rprintf(r, "%u\n", random_value);
  128.     }
  129.     close(random_fd);
  130.  
  131.     // fprintf(stderr, "Count: %d\n", count);
  132.     // fflush(stderr);
  133.  
  134.     return ret;
  135. }
  136.  
  137. static void mod_randomint_register_hooks (apr_pool_t *p)
  138. {
  139.     ap_hook_handler(mod_randomint_method_handler, NULL, NULL,APR_HOOK_LAST);
  140. }
  141.  
  142. module AP_MODULE_DECLARE_DATA randomint_module =
  143. {
  144.     STANDARD20_MODULE_STUFF,
  145.     NULL,
  146.     NULL,
  147.     NULL,
  148.     NULL,
  149.     NULL,
  150.     mod_randomint_register_hooks,    /* callback for registering hooks */
  151. };
  152.  
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