/*
 * MicroHTTPD - A minimalistic HTTP daemon.
 *
 * Written 2001 by Thunder from the hill
 */

/*
 * Include files
 */
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>

/*
 * Functions
 */
int sendfile(int Socket, char *filename);	/* Send file */
int http_request(int Socket, char *req);	/* Respond to HTTP request */
void clear(char *set, size_t len);		/* Emtpy array of size len */

/*
 * Variables
 */
int MySock;			/* Socket */
int NewSock;			/* Socket for accept. */
int peer_size = 0;		/* Name stack size for the peer */

struct sockaddr_in addr;	/* Our address */
struct sockaddr_in peer;	/* The peer's address */
struct hostent *hostentry;	/* Hostentry - for anything we need */

char *request;			/* Our HTTP request */
char *BufIn, *BufOut;		/* Input/Output-Buffer */

int BufInLen = 2048, BufOutLen = 2048;

struct arx {
  short port;
  char *basedir;
} args;

void clear(char *set, size_t len) {
  char *sptr;

  realloc(set, len + 1);

  sptr = set;

  for (sptr = set; sptr < set + len; sptr++) {
    *sptr = '\0';
  }
  return;
}

int http_request(int Socket, char *req) {
  char *req_substr;

  req_substr = strtok(req, " ");
  printf("HTTP Request: %s", req_substr);

  if (strlen(req_substr) > 0 && strcmp(req_substr, "GET") == 0) {
    req_substr = strtok(NULL, " ");
    printf(" %s\n", req_substr);
    /* if (strcmp(req_substr, "/") == 0) {
      if (sendfile(Socket, "/index.html") < 0) {
	printf("Error while sending %s in line %i!\n", req_substr, __LINE__ - 1);
	return -1;
      }
      } else */
    if (strstr(req_substr, "/internal/") != NULL) {
      if (strcmp(req_substr, "/internal/uhttpd-logo") == 0) {
	char uhttpd_logo[] = {71, 73, 70, 56, 57, 97, 100, 0, 25, 0, -9, 0, 0,
	  0, 0, -128, 124, 124, -67, -102, -102, -51, -31, -31, -16, -23, -23,
	  -12, -16, -16, -9, -8, -8, -5, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44,
	  0, 0, 0, 0, 100, 0, 25, 0, 71, 8, -4, 0, 1, 8, 28, 72, -80, -96, -63,
	  -125, 8, 19, 42, 92, -56, -80, -95, -61, -127, 5, 34, 70, 76, 56, 96,
	  34, -128, -118, 22, 21, 22, 104, -72, -15, 96, 71, -126, 31, 25,
	  -122, 124, 88, 48, 35, -56, -111, 26, 81, -110, 116, -88, 114, -91,
	  -53, -105, 48, 99, -54, 76, 104, 114, 102, -53, -103, 56, 89, 74,
	  -108, 88, 50, 100, 77, -113, 39, 81, 126, -12, 105, -112, -88, -64,
	  -114, 67, 115, -98, 124, -8, 83, -87, 83, -105, 60, 87, -18, 124, 74,
	  -107, 41, -43, -90, 85, -77, 70, 45, -22, -13, 38, -60, -98, 38, 45,
	  26, 5, 73, -10, -88, -39, -77, 76, -57, 114, -35, -71, -43, -93, -41,
	  -81, 104, -113, -114, 20, -37, 118, 106, -50, -102, 88, -117, 102,
	  -35, -5, -78, 109, 79, -66, -128, 117, -78, 29, 60, 56, -80, 97, -82,
	  56, -13, 30, -66, 123, 117, -79, 86, -118, 22, 49, -66, 5, 48, -103,
	  50, 66, -95, 86, 97, 42, 14, -5, -106, -16, 101, -54, 93, 51, -38,
	  -75, 43, 87, 113, 80, -62, 126, 65, 47, 93, -117, -70, -80, -27, -72,
	  -104, -31, -66, 78, 42, -107, -76, -37, 0, 0, 4, 96, 92, -24, 26, 40,
	  108, -67, -78, -111, -54, -42, -36, -110, 109, -128, -120, 3, 104,
	  86, -106, -71, -100, -71, -48, -26, -51, 29, 59, -1, 88, 81, 100,
	  116, -23, 119, 77, -85, -58, -50, 29, 98, -21, -21, 4, -35, 11, 6, 4,
	  0, 33, -2, -45, 84, 104, 105, 115, 32, 102, 105, 108, 101, 32, 119,
	  97, 115, 32, 99, 114, 101, 97, 116, 101, 100, 32, 98, 121, 13, 13,
	  71, 114, 97, 112, 104, 105, 99, 32, 87, 111, 114, 107, 115, 104, 111,
	  112, -103, 32, 80, 114, 111, 102, 101, 115, 115, 105, 111, 110, 97,
	  108, 32, 50, 46, 48, 97, 13, 13, 102, 114, 111, 109, 32, 65, 108, 99,
	  104, 101, 109, 121, 32, 77, 105, 110, 100, 119, 111, 114, 107, 115,
	  32, 73, 110, 99, 46, 13, 104, 116, 116, 112, 58, 47, 47, 119, 119,
	  119, 46, 109, 105, 110, 100, 119, 111, 114, 107, 115, 104, 111, 112,
	  46, 99, 111, 109, 13, 13, 84, 104, 105, 115, 32, 105, 109, 97, 103,
	  101, 32, 109, 97, 121, 32, 104, 97, 118, 101, 32, 98, 101, 101, 110,
	  32, 99, 114, 101, 97, 116, 101, 100, 32, 98, 121, 13, 97, 32, 112,
	  97, 114, 116, 121, 32, 111, 116, 104, 101, 114, 32, 116, 104, 97,
	  110, 32, 65, 108, 99, 104, 101, 109, 121, 32, 77, 105, 110, 100, 119,
	  111, 114, 107, 115, 32, 73, 110, 99, 46, 13, 13, 85, 115, 101, 32,
	  110, 111, 32, 104, 111, 111, 107, 115, 0, 59, -1, '\0'};

	clear(BufOut, BufOutLen);
	if (BufOutLen < 1536 || BufOutLen > 2560) {
	  realloc(BufOut, 1536);
	  BufOutLen = 1536;
	}

	strcpy(BufOut, uhttpd_logo);
      } else if (strcmp(req_substr, "/internal/uhttpd-version") == 0) {
	clear(BufOut, BufOutLen);
	if (BufOutLen < 2304 || BufOutLen > 2560) {
	  realloc(BufOut, 2304);
	  BufOutLen = 2304;
	}
	strcpy(BufOut, "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">\n<html>\n <head>\n  <title>The MicroHTTPD</title>\n  <meta name=\"AUTHOR\" content=\"Thunder from the hill\">\n  <meta name=\"GENERATOR\" content=\"MicroHTTPD internal data\">\n </head>\n <body bgcolor=\"#040050\" text=\"#FFFFE0\" link=\"#F0F040\" vlink=\"#F0F040\" alink=\"#F0F040\">\n  <table width=\"100%%\"><tr><td align=\"left\"><img src=\"/internal/uhttpd-logo\" alt=\"uhttpd logo\"></td><td align=\"right\">Want something tiny at home instead of huge HTTP servers? We have it: <big>MicroHTTPD</big></td></tr></table>\n  <h1 align=\"center\">MicroHTTPD</h1>\n  <p align=\"justify\">The MicroHTTPD (or evern more short, uhttpd) is a very small OpenSource HTTP daemon. CGIs are not yet supported, but may come later. If you like it, please tell <a href=\"mailto:thunder@ngforever.de\" onMouseover=\"status=\'Click here to send a mail to Thunder from the hill!'; return true;\" onMouseout=\"status=\'\'; return true;\">the author</a>!\n  <h1 align=\"center\">License</h1>\n  <p align=\"justify\">MicroHTTPD v1.0 - a minimalistic HTTP daemon.<br>\n   Copyright (c) 2001, Thunder from the hill.<br><br>\n   This server is free software; you can redistribute and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License or (at your option) any later version.<br><br>\n   This server is distributed in hope that it will be useful, but <b>WITHOUT ANY WARRANTY</b>; without even the implied warranty of <b>MERCHANTABILITY</b> or <b>FITNESS FOR A PARTICULAR PURPOSE</b>. See the GNU General Public License for more details.<br><br>\n   For the license, visit <a href=\"http://www.gnu.org/\">the GNU website</a>!<br><br><br>\n  Thunder from the hill hereby disclaims any copyright interest in the server &raquo;MicroHTTPD&laquo; (a minimalistic web server), written by Thunder from the hill.<br>thunder, April 28, 2001<br>Thunder from the hill, OpenSource Author\n  <p align=\"center\">Visit <a href=\"http://members.tripod.de/fromthehill/uhttpd/\" onMouseover=\"status=\'Click here to visit the MicroHTTPD site!\'; return true;\" onMouseout=\"status=\'\'; return true;\">this site</a> for updates and news!</p>\n </body>\n</html>\n");
      } else if (strcmp(req_substr, "/internal/getuhttpdversion") == 0) {
	clear(BufOut, BufOutLen);
	if (BufOutLen < 16 || BufOutLen > 128) {
	  realloc(BufOut, 16);
	  BufOutLen = 16;
	}

	strcpy(BufOut, "1.0\n");
      } else {
	clear(BufOut, BufOutLen);
	if (BufOutLen < 16 || BufOutLen > 128) {
	  realloc(BufOut, 16);
	  BufOutLen = 16;
	}

	strcpy(BufOut, "HTTP/1.0 404\n");
	printf("Answered 404\n");
      }
      if (send(Socket, BufOut, BufOutLen, 0) < strlen(BufOut)) {
	printf("Error while sending %i bytes in line %i!\n", strlen(BufOut), __LINE__ - 1);
	return -1;
      }
    } else {
      /* req_substr = strtok(NULL, " "); */
      if (sendfile(Socket, req_substr) < 0) {
	printf("Error while sending %s in line %i!\n", req_substr, __LINE__ - 1);
	return -1;
      }
    }
  } else {
    printf("Invalid request method %s.\n", req_substr);
    strcpy(BufOut, "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">\n<html>\n <head>\n <title>Invalid request method</title>\n </head>\n <body>\n  <h1>Invalid request method</h1>\n  <p align=\"justify\">The desired request method was not supported by the server.</p>\n </body>\n</html>\n");
    if (send(Socket, BufOut, 1024, 0) < 0) {
      printf("Error while sending 318 bytes in line %i.\n", __LINE__ - 1);
      return -1;
    }
  }
  return 0;
}

int sendfile(int Socket, char *filename) {
  int fd;				/* File descriptor */
  char *NoQuestPtr;			/* Question marks removed */
  char fn_afterall[strlen(filename) + 20];
					/* What will be left from filename */
  char sbuf[1024];

  int i = 0;

  struct stat _thisfile;		/* Stat structure */
  struct stat *thisfile = &_thisfile;	/* Stat structure pointer */

  NoQuestPtr = strtok(filename, "?");

  if (stat(NoQuestPtr, thisfile) < 0) {
    if (send(Socket, "HTTP/1.0 404\n", 14, 0) < 0) {
      return -1;
    }
    return 0;
  }

  strcpy(fn_afterall, NoQuestPtr);

  if (S_ISDIR(thisfile->st_mode) != 0) {
    char *fn_last = NoQuestPtr + strlen(NoQuestPtr) - 1;

    printf("%s considered to be a directory (%i)\n", NoQuestPtr, S_ISDIR(thisfile->st_mode));

    /* realloc(fn_afterall, strlen(filename) + 20); */
    printf("STUB: realloc() segfaults in sendfile(Socket, \"%s\");\n", NoQuestPtr);

    printf("fn_afterall has address %p and contains string %s.\n", fn_afterall, fn_afterall);

    if (*fn_last != '/')
      strcat(fn_afterall, "/");

    strcat(fn_afterall, "index.html");
  }

  if ((fd = open(fn_afterall, O_RDONLY)) < 0) {
    printf("Access  to %s seems denied.\n", fn_afterall);
    if (send(Socket, "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">\n<html>\n <head>\n  <title>Access to file denied.</title>\n </head>\n <body>\n  <h1>File access error</h1>\n  <p align=\"justify\">File access seems denied: chdir() worked, stat() returned OK, but file access seems denied.</p>\n </body>\n</html>\n", 347, 0) < 0) {
      return -1;
    }
    return 0;
  }

  printf("sbuf has address %p and contains %s. Clearing.\n", sbuf, sbuf);
  for (i = 0; i < 1024; i++) sbuf[i] = '\0';

  while (read(fd, sbuf, 1024) > 0) {
    if (send(Socket, sbuf, strlen(sbuf), 0) < 0) {
      return -1;
    }
  }

  if (close(fd) < 0) {
    printf("Error while closing file descriptor!\n");
  }

  if (chdir("/") < 0) {
    printf("Error when changing back to base dir (/).\n");
  }

  return 0;
}

void usage(void) {
  printf("%s [-d directory] port\n\t-d directory\n\t\tThe web directory (target for chroot).\n\tport\n\t\tThe port to bind the server to.\n", __FILE__);
  return;
}

int main (int argc, char **argv) {
  int argp = 1;

  BufOut = malloc(2048);
  BufIn = malloc(2048);
  args.basedir = malloc(24);
  strcpy(args.basedir, "/usr/local/httpd");

  if (argc < 2 || argc > 4) {
    usage();
    exit (1);
  }

  while (argp < argc) {
    if (strcmp(argv[argp], "-d") == 0) {
      if (argv[argp + 1] != NULL) {
	clear(args.basedir, strlen(args.basedir));
	realloc(args.basedir, strlen(argv[argp + 1]) + 1);
	strcpy(args.basedir, argv[argp + 1]);
	argp++; argp++;
      } else {
	printf("Parameter -d requires a directory to be set.\n");
	usage();
	exit(1);
      }
    } else {
      args.port = (short) atol(argv[argp]);
      argp++;
    }
  }
  printf("\033[2J\t\t\t --- MicroHTTPD ---\n");

  printf("Creating socket: AF_INET, SOCK_STREAM, IPPROTO_TCP.\n");
  MySock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (MySock == (~0)) {
    printf("%s: Error creating server socket.\nErrno was: %i\n", __FILE__,
		errno);
    exit(1);
  }

  printf("Setting up server socket: ");
  addr.sin_family = AF_INET;
  printf("AF_INET");
  addr.sin_port = htons(args.port);
  printf(", Port=%i", args.port);
  addr.sin_addr.s_addr = htonl(INADDR_ANY);
  printf(", any IP.\n");

  if (bind(MySock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
    printf("%s: Error when using bind.\n", __FILE__);
    if (errno == EADDRNOTAVAIL) {
      printf("Address not available.\n");
    } else if (errno == EADDRINUSE) {
      printf("Some other socket is already using the address.\n");
    } else if (errno == EINVAL) {
      printf("The socket already has an address.\n");
    } else if (errno == EACCES) {
      printf("Access to socket denied. (Maybe choose a port > 1024?)\n");
    } else if (errno == EBADF) {
      printf("Bad file descriptor. (???)\n");
    } else {
      printf("Unknown error (errno = %i)\n", errno);
    }
    exit(1);
  }

  printf("\n\t === Server socket started up and bound to port %i ===\n\n", args.port);

  printf("Listening for connections.\n");
  if (listen(MySock, 10) < 0) {
    printf("%s: Listening error. Errno is %i.\n", __FILE__, errno);
    exit(1);
  }

  peer_size = sizeof(peer);

  if (chroot(args.basedir) < 0) {
    printf("chroot() failed!\n");
    exit(1);
  }

  BufIn = malloc(1025);

  while ((NewSock = accept(MySock, (struct sockaddr *)&peer, &peer_size)) !=
		-1) {
    char host_addr[16];

    clear(BufIn, BufInLen);
    clear(BufOut, BufOutLen);

    strcpy(host_addr, inet_ntoa(peer.sin_addr));
    hostentry = gethostbyname(host_addr);
    if (hostentry == NULL) {
      printf("Connection from %s, port %i.\n", host_addr,
	     ntohs(peer.sin_port));
    } else {
      printf("Connection from %s (%s), port %i.\n", hostentry->h_name,
	     inet_ntoa(peer.sin_addr), ntohs(peer.sin_port));
    }

    errno = 0;

    if (recv(NewSock, BufIn, 1024, 0) < 0) {
      printf("%s: recv() failed. ", __FILE__);
      if (errno == EBADF) {
	printf("Bad file descriptor. (???)\n");
      } else if (errno == ENOTSOCK) {
	printf("Not a socket. (???)\n");
      } else if (errno == EWOULDBLOCK) {
	printf("Would block nonblocking mode socket.\n");
      } else if (errno == EINTR) {
	printf("Interrupted by a signal.\n");
      } else if (errno == ENOTCONN) {
	printf("Socket disconnected.\n");
      } else {
	printf("Unknown error (errno = %i)\n", errno);
      }
      errno = 0;
    }

    if (BufIn == NULL) {
      printf("Error: HTTP request was NULL!\n");
      send(NewSock, "HTTP/1.0 505\n", 1024, 0);
    } else if (http_request(NewSock, BufIn) < 0) {
      printf("Socket error %i.\n", errno);
      errno = 0;
    }

    printf("Host disconnected.\n");
    shutdown(NewSock, 2);
    close (NewSock);
  }
  if (NewSock == -1) {
    printf("Exit from bad accept() run (whatever might have happened).\n");
  }

  printf("%s: Cleaning up. Closing socket: ", __FILE__);
  close (MySock);
  printf("OK.\n");

  printf("Server: exit.\n");
  exit(0);
}