The Tor Browser: nsprpub/tools/httpget.c@97036ab72558 (annotated)

nsprpub/tools/httpget.c@97036ab72558 (annotated)

nsprpub/tools/httpget.c

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * Author: Wan-Teh Chang
  *
  * Given an HTTP URL, httpget uses the GET method to fetch the file.
  * The fetched file is written to stdout by default, or can be
  * saved in an output file.
  *
  * This is a single-threaded program.
  */
 #include "prio.h"
 #include "prnetdb.h"
 #include "prlog.h"
 #include "prerror.h"
 #include "prprf.h"
 #include "prinit.h"
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>  /* for atoi */
 #define FCOPY_BUFFER_SIZE (16 * 1024)
 #define INPUT_BUFFER_SIZE 1024
 #define LINE_SIZE 512
 #define HOST_SIZE 256
 #define PORT_SIZE 32
 #define PATH_SIZE 512
 /*
  * A buffer for storing the excess input data for ReadLine.
  * The data in the buffer starts from (including) the element pointed to
  * by inputHead, and ends just before (not including) the element pointed
  * to by inputTail.  The buffer is empty if inputHead == inputTail.
  */
 static char inputBuf[INPUT_BUFFER_SIZE];
 /*
  * inputBufEnd points just past the end of inputBuf
  */
 static char *inputBufEnd = inputBuf + sizeof(inputBuf);
 static char *inputHead = inputBuf;
 static char *inputTail = inputBuf;
 static PRBool endOfStream = PR_FALSE;
 /*
  * ReadLine --
  *
  * Read in a line of text, terminated by CRLF or LF, from fd into buf.
  * The terminating CRLF or LF is included (always as '\n').  The text
  * in buf is terminated by a null byte.  The excess bytes are stored in
  * inputBuf for use in the next ReadLine call or FetchFile call.
  * Returns the number of bytes in buf.  0 means end of stream.  Returns
  * -1 if read fails.
  */
 PRInt32 ReadLine(PRFileDesc *fd, char *buf, PRUint32 bufSize)
 {
     char *dst = buf;
     char *bufEnd = buf + bufSize;  /* just past the end of buf */
     PRBool lineFound = PR_FALSE;
     char *crPtr = NULL;  /* points to the CR ('\r') character */
     PRInt32 nRead;
 loop:
     PR_ASSERT(inputBuf <= inputHead && inputHead <= inputTail
 	    && inputTail <= inputBufEnd);
     while (lineFound == PR_FALSE && inputHead != inputTail
 	    && dst < bufEnd - 1) {
 	if (*inputHead == '\r') {
 	    crPtr = dst;
 	} else if (*inputHead == '\n') {
 	    lineFound = PR_TRUE;
 	    if (crPtr == dst - 1) {
 		dst--;
 	    }
 	}
 	*(dst++) = *(inputHead++);
     }
     if (lineFound == PR_TRUE || dst == bufEnd - 1 || endOfStream == PR_TRUE) {
 	*dst = '\0';
 	return dst - buf;
     }
     /*
      * The input buffer should be empty now
      */
     PR_ASSERT(inputHead == inputTail);
     nRead = PR_Read(fd, inputBuf, sizeof(inputBuf));
     if (nRead == -1) {
 	*dst = '\0';
 	return -1;
     } else if (nRead == 0) {
 	endOfStream = PR_TRUE;
 	*dst = '\0';
 	return dst - buf;
     }
     inputHead = inputBuf;
     inputTail = inputBuf + nRead;
     goto loop;
 }
 PRInt32 DrainInputBuffer(char *buf, PRUint32 bufSize)
 {
     PRInt32 nBytes = inputTail - inputHead;
     if (nBytes == 0) {
 	if (endOfStream) {
 	    return -1;
 	} else {
 	    return 0;
 	}
     }
     if ((PRInt32) bufSize < nBytes) {
 	nBytes = bufSize;
     }
     memcpy(buf, inputHead, nBytes);
     inputHead += nBytes;
     return nBytes;
 }
 PRStatus FetchFile(PRFileDesc *in, PRFileDesc *out)
 {
     char buf[FCOPY_BUFFER_SIZE];
     PRInt32 nBytes;
     while ((nBytes = DrainInputBuffer(buf, sizeof(buf))) > 0) {
 	if (PR_Write(out, buf, nBytes) != nBytes) {
             fprintf(stderr, "httpget: cannot write to file\n");
 	    return PR_FAILURE;
 	}
     }
     if (nBytes < 0) {
 	/* Input buffer is empty and end of stream */
 	return PR_SUCCESS;
     }
     while ((nBytes = PR_Read(in, buf, sizeof(buf))) > 0) {
 	if (PR_Write(out, buf, nBytes) != nBytes) {
 	    fprintf(stderr, "httpget: cannot write to file\n");
 	    return PR_FAILURE;
         }
     }
     if (nBytes < 0) {
 	fprintf(stderr, "httpget: cannot read from socket\n");
 	return PR_FAILURE;
     }
     return PR_SUCCESS;
 }
 PRStatus FastFetchFile(PRFileDesc *in, PRFileDesc *out, PRUint32 size)
 {
     PRInt32 nBytes;
     PRFileMap *outfMap;
     void *addr;
     char *start;
     PRUint32 rem;
     PRUint32 bytesToRead;
     PRStatus rv;
     PRInt64 sz64;
     LL_UI2L(sz64, size);
     outfMap = PR_CreateFileMap(out, sz64, PR_PROT_READWRITE);
     PR_ASSERT(outfMap);
     addr = PR_MemMap(outfMap, LL_ZERO, size);
     if (addr == NULL) {
 	fprintf(stderr, "cannot memory-map file: (%d, %d)\n", PR_GetError(),
 		PR_GetOSError());
 	PR_CloseFileMap(outfMap);
 	return PR_FAILURE;
     }
     start = (char *) addr;
     rem = size;
     while ((nBytes = DrainInputBuffer(start, rem)) > 0) {
 	start += nBytes;
 	rem -= nBytes;
     }
     if (nBytes < 0) {
 	/* Input buffer is empty and end of stream */
 	return PR_SUCCESS;
     }
     bytesToRead = (rem < FCOPY_BUFFER_SIZE) ? rem : FCOPY_BUFFER_SIZE;
     while (rem > 0 && (nBytes = PR_Read(in, start, bytesToRead)) > 0) {
 	start += nBytes;
 	rem -= nBytes;
         bytesToRead = (rem < FCOPY_BUFFER_SIZE) ? rem : FCOPY_BUFFER_SIZE;
     }
     if (nBytes < 0) {
 	fprintf(stderr, "httpget: cannot read from socket\n");
 	return PR_FAILURE;
     }
     rv = PR_MemUnmap(addr, size);
     PR_ASSERT(rv == PR_SUCCESS);
     rv = PR_CloseFileMap(outfMap);
     PR_ASSERT(rv == PR_SUCCESS);
     return PR_SUCCESS;
 }
 PRStatus ParseURL(char *url, char *host, PRUint32 hostSize,
     char *port, PRUint32 portSize, char *path, PRUint32 pathSize)
 {
     char *start, *end;
     char *dst;
     char *hostEnd;
     char *portEnd;
     char *pathEnd;
     if (strncmp(url, "http", 4)) {
 	fprintf(stderr, "httpget: the protocol must be http\n");
 	return PR_FAILURE;
     }
     if (strncmp(url + 4, "://", 3) || url[7] == '\0') {
 	fprintf(stderr, "httpget: malformed URL: %s\n", url);
 	return PR_FAILURE;
     }
     start = end = url + 7;
     dst = host;
     hostEnd = host + hostSize;
     while (*end && *end != ':' && *end != '/') {
 	if (dst == hostEnd - 1) {
 	    fprintf(stderr, "httpget: host name too long\n");
 	    return PR_FAILURE;
 	}
 	*(dst++) = *(end++);
     }
     *dst = '\0';
     if (*end == '\0') {
 	PR_snprintf(port, portSize, "%d", 80);
 	PR_snprintf(path, pathSize, "%s", "/");
 	return PR_SUCCESS;
     }
     if (*end == ':') {
 	end++;
 	dst = port;
 	portEnd = port + portSize;
 	while (*end && *end != '/') {
 	    if (dst == portEnd - 1) {
 		fprintf(stderr, "httpget: port number too long\n");
 		return PR_FAILURE;
 	    }
 	    *(dst++) = *(end++);
         }
 	*dst = '\0';
 	if (*end == '\0') {
 	    PR_snprintf(path, pathSize, "%s", "/");
 	    return PR_SUCCESS;
         }
     } else {
 	PR_snprintf(port, portSize, "%d", 80);
     }
     dst = path;
     pathEnd = path + pathSize;
     while (*end) {
 	if (dst == pathEnd - 1) {
 	    fprintf(stderr, "httpget: file pathname too long\n");
 	    return PR_FAILURE;
 	}
 	*(dst++) = *(end++);
     }
     *dst = '\0';
     return PR_SUCCESS;
 }
 void PrintUsage(void) {
     fprintf(stderr, "usage: httpget url\n"
 		    "       httpget -o outputfile url\n"
 		    "       httpget url -o outputfile\n");
 }
 int main(int argc, char **argv)
 {
     PRHostEnt hostentry;
     char buf[PR_NETDB_BUF_SIZE];
     PRNetAddr addr;
     PRFileDesc *socket = NULL, *file = NULL;
     PRIntn cmdSize;
     char host[HOST_SIZE];
     char port[PORT_SIZE];
     char path[PATH_SIZE];
     char line[LINE_SIZE];
     int exitStatus = 0;
     PRBool endOfHeader = PR_FALSE;
     char *url;
     char *fileName = NULL;
     PRUint32 fileSize;
     if (argc != 2 && argc != 4) {
 	PrintUsage();
 	exit(1);
     }
     if (argc == 2) {
 	/*
 	 * case 1: httpget url
 	 */
 	url = argv[1];
     } else {
 	if (strcmp(argv[1], "-o") == 0) {
 	    /*
 	     * case 2: httpget -o outputfile url
 	     */
 	    fileName = argv[2];
 	    url = argv[3];
         } else {
 	    /*
 	     * case 3: httpget url -o outputfile
 	     */
 	    url = argv[1];
 	    if (strcmp(argv[2], "-o") != 0) {
 		PrintUsage();
 		exit(1);
             }
 	    fileName = argv[3];
 	}
     }
     if (ParseURL(url, host, sizeof(host), port, sizeof(port),
 	    path, sizeof(path)) == PR_FAILURE) {
 	exit(1);
     }
     if (PR_GetHostByName(host, buf, sizeof(buf), &hostentry)
 	    == PR_FAILURE) {
         fprintf(stderr, "httpget: unknown host name: %s\n", host);
 	exit(1);
     }
     addr.inet.family = PR_AF_INET;
     addr.inet.port = PR_htons((short) atoi(port));
     addr.inet.ip = *((PRUint32 *) hostentry.h_addr_list[0]);
     socket = PR_NewTCPSocket();
     if (socket == NULL) {
 	fprintf(stderr, "httpget: cannot create new tcp socket\n");
 	exit(1);
     }
     if (PR_Connect(socket, &addr, PR_INTERVAL_NO_TIMEOUT) == PR_FAILURE) {
 	fprintf(stderr, "httpget: cannot connect to http server\n");
 	exitStatus = 1;
 	goto done;
     }
     if (fileName == NULL) {
 	file = PR_STDOUT;
     } else {
         file = PR_Open(fileName, PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE,
 );
         if (file == NULL) {
 	    fprintf(stderr, "httpget: cannot open file %s: (%d, %d)\n",
 		    fileName, PR_GetError(), PR_GetOSError());
 	    exitStatus = 1;
 	    goto done;
 	}
     }
     cmdSize = PR_snprintf(buf, sizeof(buf), "GET %s HTTP/1.0\r\n\r\n", path);
     PR_ASSERT(cmdSize == (PRIntn) strlen("GET  HTTP/1.0\r\n\r\n")
             + (PRIntn) strlen(path));
     if (PR_Write(socket, buf, cmdSize) != cmdSize) {
 	fprintf(stderr, "httpget: cannot write to http server\n");
 	exitStatus = 1;
 	goto done;
     }
     if (ReadLine(socket, line, sizeof(line)) <= 0) {
 	fprintf(stderr, "httpget: cannot read line from http server\n");
 	exitStatus = 1;
 	goto done;
     }
     /* HTTP response: 200 == OK */
     if (strstr(line, "200") == NULL) {
 	fprintf(stderr, "httpget: %s\n", line);
 	exitStatus = 1;
 	goto done;
     }
     while (ReadLine(socket, line, sizeof(line)) > 0) {
 	if (line[0] == '\n') {
 	    endOfHeader = PR_TRUE;
 	    break;
 	}
 	if (strncmp(line, "Content-Length", 14) == 0
 		|| strncmp(line, "Content-length", 14) == 0) {
 	    char *p = line + 14;
 	    while (*p == ' ' || *p == '\t') {
 		p++;
 	    }
 	    if (*p != ':') {
 		continue;
             }
 	    p++;
 	    while (*p == ' ' || *p == '\t') {
 		p++;
 	    }
 	    fileSize = 0;
 	    while ('0' <= *p && *p <= '9') {
 		fileSize = 10 * fileSize + (*p - '0');
 		p++;
             }
 	}
     }
     if (endOfHeader == PR_FALSE) {
 	fprintf(stderr, "httpget: cannot read line from http server\n");
 	exitStatus = 1;
 	goto done;
     }
     if (fileName == NULL || fileSize == 0) {
         FetchFile(socket, file);
     } else {
 	FastFetchFile(socket, file, fileSize);
     }
 done:
     if (socket) PR_Close(socket);
     if (file) PR_Close(file);
     PR_Cleanup();
     return exitStatus;
 }

The Tor Browser / annotate

nsprpub/tools/httpget.c@97036ab72558 (annotated)

nsprpub/tools/httpget.c