📄 httpd.c
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/* * httpd.c - a simple HTTP server *//* * Copyright (C) 2002 Constantin Kaplinsky. All Rights Reserved. * Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved. * * This is free software; you can redistribute it 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. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, * USA. */#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/time.h>#include <sys/socket.h>#include <netinet/in.h>#include <netinet/tcp.h>#include <netdb.h>#include <fcntl.h>#include <errno.h>#include <unistd.h>#include <pwd.h>#include <arpa/inet.h>#ifndef USE_LIBWRAP#define USE_LIBWRAP 0#endif#if USE_LIBWRAP#include <tcpd.h>#include <arpa/inet.h>#endif#include "rfb.h"#define NOT_FOUND_STR "HTTP/1.0 404 Not found\r\n\r\n" \ "<HEAD><TITLE>File Not Found</TITLE></HEAD>\n" \ "<BODY><H1>File Not Found</H1></BODY>\n"#define OK_STR "HTTP/1.0 200 OK\r\n\r\n"static void httpProcessInput();static Bool compareAndSkip(char **ptr, const char *str);static Bool parseParams(const char *request, char *result, int max_bytes);static Bool validateString(char *str);int httpPort = 0;char *httpDir = NULL;int httpListenSock = -1;int httpSock = -1;#define BUF_SIZE 32768static char buf[BUF_SIZE];static size_t buf_filled = 0;/* * httpInitSockets sets up the TCP socket to listen for HTTP connections. */voidhttpInitSockets(){ static Bool done = FALSE; if (done) return; done = TRUE; if (!httpDir) return; if (httpPort == 0) { httpPort = 5800 + atoi(display); } rfbLog("Listening for HTTP connections on TCP port %d\n", httpPort); rfbLog(" URL http://%s:%d\n",rfbThisHost,httpPort); if ((httpListenSock = ListenOnTCPPort(httpPort)) < 0) { rfbLogPerror("ListenOnTCPPort"); exit(1); } AddEnabledDevice(httpListenSock);}/* * httpCheckFds is called from ProcessInputEvents to check for input on the * HTTP socket(s). If there is input to process, httpProcessInput is called. */voidhttpCheckFds(){ int nfds, n; fd_set fds; struct timeval tv; struct sockaddr_in addr; socklen_t addrlen = sizeof(addr); if (!httpDir) return; FD_ZERO(&fds); FD_SET(httpListenSock, &fds); if (httpSock >= 0) { FD_SET(httpSock, &fds); } tv.tv_sec = 0; tv.tv_usec = 0; nfds = select(max(httpSock,httpListenSock) + 1, &fds, NULL, NULL, &tv); if (nfds == 0) { return; } if (nfds < 0) { rfbLogPerror("httpCheckFds: select"); return; } if ((httpSock >= 0) && FD_ISSET(httpSock, &fds)) { httpProcessInput(); } if (FD_ISSET(httpListenSock, &fds)) { int flags; if (httpSock >= 0) close(httpSock); if ((httpSock = accept(httpListenSock, (struct sockaddr *)&addr, &addrlen)) < 0) { rfbLogPerror("httpCheckFds: accept"); return; }#if USE_LIBWRAP if (!hosts_ctl("Xvnc", STRING_UNKNOWN, inet_ntoa(addr.sin_addr), STRING_UNKNOWN)) { rfbLog("Rejected HTTP connection from client %s\n", inet_ntoa(addr.sin_addr)); close(httpSock); httpSock = -1; return; }#endif flags = fcntl (httpSock, F_GETFL); if (flags == -1 || fcntl (httpSock, F_SETFL, flags | O_NONBLOCK) == -1) { rfbLogPerror("httpCheckFds: fcntl"); close (httpSock); httpSock = -1; return; } AddEnabledDevice(httpSock); }}static voidhttpCloseSock(){ close(httpSock); RemoveEnabledDevice(httpSock); httpSock = -1; buf_filled = 0;}/* * httpProcessInput is called when input is received on the HTTP socket. */static voidhttpProcessInput(){ struct sockaddr_in addr; socklen_t addrlen = sizeof(addr); char fullFname[512]; char params[1024]; char *ptr; char *fname; int maxFnameLen; int fd; Bool performSubstitutions = FALSE; char str[256]; struct passwd *user; user = getpwuid(getuid()); if (strlen(httpDir) > 255) { rfbLog("-httpd directory too long\n"); httpCloseSock(); return; } strcpy(fullFname, httpDir); fname = &fullFname[strlen(fullFname)]; maxFnameLen = 511 - strlen(fullFname); /* Read data from the HTTP client until we get a complete request. */ while (1) { ssize_t got = read (httpSock, buf + buf_filled, sizeof (buf) - buf_filled - 1); if (got <= 0) { if (got == 0) { rfbLog("httpd: premature connection close\n"); } else { if (errno == EAGAIN) { return; } rfbLogPerror("httpProcessInput: read"); } httpCloseSock(); return; } buf_filled += got; buf[buf_filled] = '\0'; /* Is it complete yet (is there a blank line)? */ if (strstr (buf, "\r\r") || strstr (buf, "\n\n") || strstr (buf, "\r\n\r\n") || strstr (buf, "\n\r\n\r")) break; } /* Process the request. */ if (strncmp(buf, "GET ", 4)) { rfbLog("httpd: no GET line\n"); httpCloseSock(); return; } else { /* Only use the first line. */ buf[strcspn(buf, "\n\r")] = '\0'; } if (strlen(buf) > maxFnameLen) { rfbLog("httpd: GET line too long\n"); httpCloseSock(); return; } if (sscanf(buf, "GET %s HTTP/1.0", fname) != 1) { rfbLog("httpd: couldn't parse GET line\n"); httpCloseSock(); return; } if (fname[0] != '/') { rfbLog("httpd: filename didn't begin with '/'\n"); WriteExact(httpSock, NOT_FOUND_STR, strlen(NOT_FOUND_STR)); httpCloseSock(); return; } if (strchr(fname+1, '/') != NULL) { rfbLog("httpd: asking for file in other directory\n"); WriteExact(httpSock, NOT_FOUND_STR, strlen(NOT_FOUND_STR)); httpCloseSock(); return; } getpeername(httpSock, (struct sockaddr *)&addr, &addrlen); rfbLog("httpd: get '%s' for %s\n", fname+1, inet_ntoa(addr.sin_addr)); /* Extract parameters from the URL string if necessary */ params[0] = '\0'; ptr = strchr(fname, '?'); if (ptr != NULL) { *ptr = '\0'; if (!parseParams(&ptr[1], params, 1024)) { params[0] = '\0'; rfbLog("httpd: bad parameters in the URL\n"); } } /* If we were asked for '/', actually read the file index.vnc */ if (strcmp(fname, "/") == 0) { strcpy(fname, "/index.vnc"); rfbLog("httpd: defaulting to '%s'\n", fname+1); } /* Substitutions are performed on files ending .vnc */ if (strlen(fname) >= 4 && strcmp(&fname[strlen(fname)-4], ".vnc") == 0) { performSubstitutions = TRUE; } /* Open the file */ if ((fd = open(fullFname, O_RDONLY)) < 0) { rfbLogPerror("httpProcessInput: open"); WriteExact(httpSock, NOT_FOUND_STR, strlen(NOT_FOUND_STR)); httpCloseSock(); return; } WriteExact(httpSock, OK_STR, strlen(OK_STR)); while (1) { int n = read(fd, buf, BUF_SIZE-1); if (n < 0) { rfbLogPerror("httpProcessInput: read"); close(fd); httpCloseSock(); return; } if (n == 0) break; if (performSubstitutions) { /* Substitute $WIDTH, $HEIGHT, etc with the appropriate values. This won't quite work properly if the .vnc file is longer than BUF_SIZE, but it's reasonable to assume that .vnc files will always be short. */ char *ptr = buf; char *dollar; buf[n] = 0; /* make sure it's null-terminated */ while (dollar = strchr(ptr, '$')) { WriteExact(httpSock, ptr, (dollar - ptr)); ptr = dollar; if (compareAndSkip(&ptr, "$WIDTH")) { sprintf(str, "%d", rfbScreen.width); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$HEIGHT")) { sprintf(str, "%d", rfbScreen.height); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$APPLETWIDTH")) { sprintf(str, "%d", rfbScreen.width); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$APPLETHEIGHT")) { sprintf(str, "%d", rfbScreen.height + 32); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$PORT")) { sprintf(str, "%d", rfbPort); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$DESKTOP")) { WriteExact(httpSock, desktopName, strlen(desktopName)); } else if (compareAndSkip(&ptr, "$DISPLAY")) { sprintf(str, "%s:%s", rfbThisHost, display); WriteExact(httpSock, str, strlen(str)); } else if (compareAndSkip(&ptr, "$USER")) { if (user) { WriteExact(httpSock, user->pw_name, strlen(user->pw_name)); } else { WriteExact(httpSock, "?", 1); } } else if (compareAndSkip(&ptr, "$PARAMS")) { if (params[0] != '\0') WriteExact(httpSock, params, strlen(params)); } else { if (!compareAndSkip(&ptr, "$$")) ptr++; if (WriteExact(httpSock, "$", 1) < 0) { close(fd); httpCloseSock(); return; } } } if (WriteExact(httpSock, ptr, (&buf[n] - ptr)) < 0) break; } else { /* For files not ending .vnc, just write out the buffer */ if (WriteExact(httpSock, buf, n) < 0) break; } } close(fd); httpCloseSock();}static BoolcompareAndSkip(char **ptr, const char *str){ if (strncmp(*ptr, str, strlen(str)) == 0) { *ptr += strlen(str); return TRUE; } return FALSE;}/* * Parse the request tail after the '?' character, and format a sequence * of <param> tags for inclusion into an HTML page with embedded applet. */static BoolparseParams(const char *request, char *result, int max_bytes){ char param_request[128]; char param_formatted[196]; const char *tail; char *delim_ptr; char *value_str; int cur_bytes, len; result[0] = '\0'; cur_bytes = 0; tail = request; for (;;) { /* Copy individual "name=value" string into a buffer */ delim_ptr = strchr((char *)tail, '&'); if (delim_ptr == NULL) { if (strlen(tail) >= sizeof(param_request)) { return FALSE; } strcpy(param_request, tail); } else { len = delim_ptr - tail; if (len >= sizeof(param_request)) { return FALSE; } memcpy(param_request, tail, len); param_request[len] = '\0'; } /* Split the request into parameter name and value */ value_str = strchr(¶m_request[1], '='); if (value_str == NULL) { return FALSE; } *value_str++ = '\0'; if (strlen(value_str) == 0) { return FALSE; } /* Validate both parameter name and value */ if (!validateString(param_request) || !validateString(value_str)) { return FALSE; } /* Prepare HTML-formatted representation of the name=value pair */ len = sprintf(param_formatted, "<PARAM NAME=\"%s\" VALUE=\"%s\">\n", param_request, value_str); if (cur_bytes + len + 1 > max_bytes) { return FALSE; } strcat(result, param_formatted); cur_bytes += len; /* Go to the next parameter */ if (delim_ptr == NULL) { break; } tail = delim_ptr + 1; } return TRUE;}/* * Check if the string consists only of alphanumeric characters, '+' * signs, underscores, and dots. Replace all '+' signs with spaces. */static BoolvalidateString(char *str){ char *ptr; for (ptr = str; *ptr != '\0'; ptr++) { if (!isalnum(*ptr) && *ptr != '_' && *ptr != '.') { if (*ptr == '+') { *ptr = ' '; } else { return FALSE; } } } return TRUE;}⌨️ 快捷键说明
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