tests/scgi-responder.c

   1 /*
   2  * simple and trivial SCGI server with hard-coded results for use in unit tests
   3  * - listens on STDIN_FILENO (socket on STDIN_FILENO must be set up by caller)
   4  * - processes a single SCGI request at a time
   5  * - arbitrary limitation: reads request headers netstring up to 64k in size
   6  * - expect recv data for request headers netstring every 10ms or less
   7  * - no read timeouts for request body; might block reading request body
   8  * - no write timeouts; might block writing response
   9  */
  10
  11 #include <sys/types.h>
  12 #include <sys/socket.h>
  13 #include <assert.h>
  14 #include <errno.h>
  15 #include <fcntl.h>
  16 #include <limits.h>
  17 #include <poll.h>
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <unistd.h>
  22
  23 #ifndef MSG_DONTWAIT
  24 #define MSG_DONTWAIT 0
  25 #endif
  26
  27 static int finished;
  28 static char buf[65536];
  29
  30
  31 static char *
  32 scgi_getenv(char *r, const unsigned long rlen, const char * const name)
  33 {
  34     /* simple search;
  35      * if many lookups are done, then should use more efficient data structure*/
  36     char * const end = r+rlen;
  37     char *z;
  38     const size_t len = strlen(name);
  39     do {
  40         if (0 == strcmp(r, name)) return r+len+1;
  41
  42         z = memchr(r, '\0', (size_t)(end-r));
  43         if (NULL == z) return NULL;
  44         z = memchr(z+1, '\0', (size_t)(end-r));
  45         if (NULL == z) return NULL;
  46         r = z+1;
  47     } while (r < end);
  48     return NULL;
  49 }
  50
  51
  52 static void
  53 scgi_process (const int fd)
  54 {
  55     ssize_t rd = 0, offset = 0;
  56     int num_requests = 1;
  57     char *p = NULL, *r;
  58     unsigned long rlen;
  59     long long cl;
  60
  61     assert(fd == STDOUT_FILENO); /*(required for response sent with printf())*/
  62     fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
  63
  64     do {
  65         struct pollfd pfd = { fd, POLLIN, 0 };
  66         switch (poll(&pfd, 1, 10)) { /* 10ms timeout */
  67           default: /* 1; the only pfd has revents */
  68             break;
  69           case -1: /* error */
  70           case  0: /* timeout */
  71             pfd.revents |= POLLERR;
  72             break;
  73         }
  74         if (!(pfd.revents & POLLIN))
  75             break;
  76         do {
  77             rd = recv(fd, buf+offset, sizeof(buf)-offset, MSG_DONTWAIT);
  78         } while (rd < 0 && errno == EINTR);
  79         if (rd > 0)
  80             offset += rd;
  81         else if (0 == rd) {
  82             p = memchr(buf, ':', offset);
  83             break;
  84         }
  85         else if (errno == EAGAIN || errno == EWOULDBLOCK)
  86             continue;
  87         else
  88             break;
  89     } while (NULL == (p = memchr(buf,':',offset)) && offset < 21);
  90     if (NULL == p)
  91         return; /* timeout or error receiving start of netstring */
  92     rlen = strtoul(buf, &p, 10);
  93     if (*buf == '-' || *p != ':' || p == buf || rlen == ULONG_MAX)
  94         return; /* invalid netstring (and rlen == ULONG_MAX is too long)*/
  95     if (rlen > sizeof(buf) - (p - buf) - 2)
  96         return; /* netstring longer than arbitrary limit we accept here */
  97     rlen += (p - buf) + 2;
  98
  99     while ((ssize_t)rlen < offset) {
 100         struct pollfd pfd = { fd, POLLIN, 0 };
 101         switch (poll(&pfd, 1, 10)) { /* 10ms timeout */
 102           default: /* 1; the only pfd has revents */
 103             break;
 104           case -1: /* error */
 105           case  0: /* timeout */
 106             pfd.revents |= POLLERR;
 107             break;
 108         }
 109         if (!(pfd.revents & POLLIN))
 110             break;
 111         do {
 112             rd = recv(fd, buf+offset, sizeof(buf)-offset, MSG_DONTWAIT);
 113         } while (rd < 0 && errno == EINTR);
 114         if (rd > 0)
 115             offset += rd;
 116         else if (0 == rd)
 117             break;
 118         else if (errno == EAGAIN || errno == EWOULDBLOCK)
 119             continue;
 120         else
 121             break;
 122     }
 123     if (offset < (ssize_t)rlen)
 124         return; /* timeout or error receiving netstring */
 125     if (buf[rlen-1] != ',')
 126         return; /* invalid netstring */
 127     rlen -= (p - buf) + 2;
 128     r = p+1;
 129
 130     /* not checking for empty headers in SCGI request (empty values allowed) */
 131
 132     /* SCGI request must contain "SCGI" header with value "1" */
 133     p = scgi_getenv(r, rlen, "SCGI");
 134     if (NULL == p || p[0] != '1' || p[1] != '\0')
 135         return; /* missing or invalid SCGI header */
 136
 137     /* CONTENT_LENGTH must be first header in SCGI request; always required */
 138     if (0 != strcmp(r, "CONTENT_LENGTH"))
 139         return; /* missing CONTENT_LENGTH */
 140
 141     errno = 0;
 142     cl = strtoll(r+sizeof("CONTENT_LENGTH"), &p, 10);
 143     if (*p != '\0' || p == r+sizeof("CONTENT_LENGTH") || cl < 0 || 0 != errno)
 144         return; /* invalid CONTENT_LENGTH */
 145
 146     fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
 147
 148     /* read,discard request body (currently ignored in these SCGI unit tests)
 149      * (make basic effort to read body; ignore any timeouts or errors here) */
 150     cl -= (offset - (r+rlen+1 - buf));
 151     while (cl > 0) {
 152         char x[8192];
 153         do {
 154             rd = recv(fd, x, (cl>(long long)sizeof(x)?sizeof(x):(size_t)cl), 0);
 155         } while (rd < 0 && errno == EINTR);
 156         if (rd <= 0)
 157             break;
 158         cl -= rd;
 159     }
 160
 161     /*(from fcgi-responder.c, substituting scgi_getenv() for getenv())*/
 162     {
 163                 if (NULL != (p = scgi_getenv(r, rlen, "QUERY_STRING"))) {
 164                         if (0 == strcmp(p, "lf")) {
 165                                 printf("Status: 200 OK\n\n");
 166                         } else if (0 == strcmp(p, "crlf")) {
 167                                 printf("Status: 200 OK\r\n\r\n");
 168                         } else if (0 == strcmp(p, "slow-lf")) {
 169                                 printf("Status: 200 OK\n");
 170                                 fflush(stdout);
 171                                 printf("\n");
 172                         } else if (0 == strcmp(p,"slow-crlf")) {
 173                                 printf("Status: 200 OK\r\n");
 174                                 fflush(stdout);
 175                                 printf("\r\n");
 176                         } else if (0 == strcmp(p, "die-at-end")) {
 177                                 printf("Status: 200 OK\r\n\r\n");
 178                                 num_requests--;
 179                         } else {
 180                                 printf("Status: 200 OK\r\n\r\n");
 181                         }
 182                 } else {
 183                         printf("Status: 500 Internal Foo\r\n\r\n");
 184                 }
 185
 186                 if (0 == strcmp(p, "path_info")) {
 187                         printf("%s", scgi_getenv(r, rlen, "PATH_INFO"));
 188                 } else if (0 == strcmp(p, "script_name")) {
 189                         printf("%s", scgi_getenv(r, rlen, "SCRIPT_NAME"));
 190                 } else if (0 == strcmp(p, "var")) {
 191                         p = scgi_getenv(r, rlen, "X_LIGHTTPD_FCGI_AUTH");
 192                         printf("%s", p ? p : "(no value)");
 193                 } else {
 194                         printf("test123");
 195                 }
 196     }
 197
 198     fflush(stdout);
 199     if (0 == num_requests) finished = 1;
 200 }
 201
 202
 203 int
 204 main (void)
 205 {
 206     int fd;
 207     fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL) & ~O_NONBLOCK);
 208     close(STDOUT_FILENO); /*(so that accept() returns fd to STDOUT_FILENO)*/
 209
 210     do {
 211         fd = accept(STDIN_FILENO, NULL, NULL);
 212         if (fd < 0)
 213             continue;
 214         assert(fd == STDOUT_FILENO);
 215         scgi_process(fd);
 216     } while (fd > 0 ? 0 == close(fd) && !finished : errno == EINTR);
 217
 218     return 0;
 219 }