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url.c
/*************************************************************************/
/* */
/* Copyright (c) 1997-98 Richard Tobin, Language Technology Group, HCRC, */
/* University of Edinburgh. */
/* */
/* THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHOR OR THE UNIVERSITY OF EDINBURGH BE LIABLE */
/* FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF */
/* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION */
/* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/* */
/*************************************************************************/
#ifdef FOR_LT
#include "lt-defs.h"
#include "lt-memory.h"
#include "lt-errmsg.h"
#include "lt-comment.h"
#include "lt-safe.h"
#include "nsl-err.h"
#define Strerror() strErr()
#define Malloc salloc
#define Realloc srealloc
#define Free sfree
#define fopen stdsfopen
#else
#include "system.h"
#define LT_ERROR(err, format) fprintf(stderr, format)
#define LT_ERROR1(err, format, arg) fprintf(stderr, format, arg)
#define LT_ERROR2(err, format, arg1, arg2) fprintf(stderr, format, arg1, arg2)
#define LT_ERROR3(err, format, arg1, arg2, arg3) fprintf(stderr, format, arg1, arg2, arg3)
#define WARN(err, format) fprintf(stderr, format)
#define WARN1(err, format, arg) fprintf(stderr, format, arg)
#define Strerror() strerror(errno)
#ifdef MAXPATHLEN
#define CWDBS MAXPATHLEN+1
#else
#define CWDBS 1025
#endif
#define GETWD(buf) getcwd(buf,CWDBS)
#endif /* FOR_LT */
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <string.h> /* that's where strerror is. really. */
#include <sys/types.h>
#ifdef WIN32
#include <direct.h>
#endif
#ifdef SOCKETS_IMPLEMENTED
#ifdef WIN32
#undef boolean
#include <winsock.h>
#include <fcntl.h>
#else
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#endif
#endif
#include "string16.h"
#include "stdio16.h"
#include "url.h"
#ifdef HAVE_LIBZ
#include "zlib.h"
#ifdef macintosh
#include <fcntl.h>
#include <unix.h>
#endif
#endif
static FILE16 *http_open(const char *url,
const char *host, int port, const char *path,
const char *type);
static FILE16 *file_open(const char *url,
const char *host, int port, const char *path,
const char *type);
static void parse_url(const char *url,
char **scheme, char **host, int *port, char **path);
/* Mapping of scheme names to opening functions */
struct {
char *scheme;
FILE16 *(*open)(const char *, const char *, int, const char *, const char *);
} schemes[] = {
{(char *)"http", http_open},
{(char *)"file", file_open},
};
#define NSCHEME (sizeof(schemes) / sizeof(schemes[0]))
/* Construct a default base URL, essentially file:`pwd`/ */
char *default_base_url(void)
{
char buf[CWDBS];
char *url;
if(!GETWD(buf))
{
WARN(LEFILE, "Warning: can't get current directory for default base url\n");
return strdup8("file:/");
}
#ifdef WIN32
/* DOS: translate C:\a\b to file:/C:/a/b/ */
/* XXX should we escape anything? */
{
char *p;
for(p=buf; *p; p++)
if(*p == '\\')
*p = '/';
}
url = Malloc(6 + strlen(buf) + 2);
sprintf(url, "file:/%s/", buf);
#else
#ifdef mac_filenames
/* Mac: translate a:b to file:/a/b/ */
/* XXX should escape spaces and slashes, at least */
{
char *p;
for(p=buf; *p; p++)
if(*p == ':')
*p = '/';
/* Mac getcwd (always?) has a trailing separator, which we here bash */
if(*--p == '/')
*p = 0;
}
url = Malloc(6 + strlen(buf) + 2);
sprintf(url, "file:/%s/", buf);
#else
/* Unix: translate /a/b to file:/a/b/ */
url = Malloc(5 + strlen(buf) + 2);
sprintf(url, "file:%s/", buf);
#endif
#endif
return url;
}
/*
* Merge a URL with a base URL if necessary.
* The merged URL is returned.
* The parts of the URL are returned in scheme, host, port and path
* if these are non-null.
* Caller should free the results.
*/
char *url_merge(const char *url, const char *base,
char **_scheme, char **_host, int *_port, char **_path)
{
char *merged_scheme, *merged_host, *merged_path, *merged_url;
char *scheme=0, *host=0, *path=0;
char *base_scheme=0, *base_host=0, *base_path=0;
char *default_base=0;
int port, base_port, merged_port, i, j;
char *p;
/* First see if we have an absolute URL */
parse_url(url, &scheme, &host, &port, &path);
if(scheme && (host || *path == '/'))
{
merged_scheme = scheme;
merged_host = host;
merged_port = port;
merged_path = path;
merged_url = strdup8(url);
goto ok;
}
/* Relative URL, so we need the base URL */
if(!base)
base = default_base = default_base_url();
parse_url(base, &base_scheme, &base_host, &base_port, &base_path);
if(base_scheme && (base_host || *base_path == '/'))
;
else
{
LT_ERROR1(LEFILE, "Error: bad base URL <%s>\n", base);
goto bad;
}
/* Determine merged path */
if(path[0] == '/')
{
/* not relative, use as-is */
merged_path = path;
path = 0;
}
else
{
/* relative, append to base path */
merged_path = Malloc(strlen(base_path) + strlen(path) + 1);
strcpy(merged_path, base_path);
/* strip last component of base */
for(i=strlen(merged_path)-1; i>=0 && merged_path[i] != '/'; i--)
merged_path[i] = '\0';
/* append relative path */
strcat(merged_path, path);
/* Remove . and .. components from path */
p = merged_path;
for(i=0; p[i]; )
{
assert(p[i] == '/');
/* find next segment */
for(j=i+1; p[j] && p[j] != '/'; j++)
;
/* Do we have "." ? */
if(j - i == 2 && p[i+1] == '.')
{
strcpy(&p[i+1], p[j] ? &p[j+1] : &p[j]);
continue;
}
/* Do we have "<segment>/.." with <segment> != ".." ? */
/* (We know we're not looking at "./" so we don't have to
* worry about "./..")
*/
if(p[j] == '/' && p[j+1] == '.' && p[j+2] == '.' &&
(p[j+3] == '/' || p[j+3] == '\0') &&
(j - i != 3 || p[i+1] != '.' || p[i+2] != '.'))
{
strcpy(&p[i+1], p[j+3] ? &p[j+4] : &p[j+3]);
i = 0; /* start again from beginning */
continue;
}
/* move to next segment */
i = j;
}
}
/* Check for deviant relative URLs like file:foo */
if(scheme && !host && *path != '/')
{
if(strcmp(scheme, base_scheme) == 0)
{
WARN1(LEFILE,
"Warning: relative URL <%s> contains scheme, contrary to RFC 1808\n",
url);
}
else
{
LT_ERROR2(LEFILE,
"Error: relative URL <%s> has scheme different from base <%s>\n",
url, base);
goto bad;
}
}
/* Return the parts and the whole thing */
merged_scheme = base_scheme; if(scheme) Free(scheme);
if(host)
{
merged_host = host; Free(base_host);
merged_port = port;
}
else
{
merged_host = base_host;
merged_port = base_port;
}
Free(path); Free(base_path);
merged_url = Malloc(strlen(merged_scheme) + 1 +
(merged_host ? 2 + strlen(merged_host) + 10 : 0) +
strlen(merged_path) + 1);
if(merged_host)
{
if(merged_port == -1)
sprintf(merged_url, "%s://%s%s",
merged_scheme, merged_host, merged_path);
else
sprintf(merged_url, "%s://%s:%d%s",
merged_scheme, merged_host, merged_port, merged_path);
}
else
sprintf(merged_url, "%s:%s", merged_scheme, merged_path);
ok:
Free(default_base);
if(_scheme) *_scheme = merged_scheme; else Free(merged_scheme);
if(_host) *_host = merged_host; else Free(merged_host);
if(_port) *_port = merged_port;
if(_path) *_path = merged_path; else Free(merged_path);
return merged_url;
bad:
Free(default_base);
Free(scheme);
Free(host);
Free(path);
Free(base_scheme);
Free(base_host);
Free(base_path);
return NULL;
}
/*
* Open a stream to a URL.
* url may be a relative URL, in which case it is merged with base,
* which is typically the URL of the containing document. If base
* is null, file:`pwd`/ is used, which is the right thing to do for
* filenames. If base is "", there is no base URL and relative
* URLs will fail.
* If merged_url is non-null the resulting URL is stored in it.
* If type begins "r", the URL is opened for reading, if "w" for
* writing. Writing is only supported for file URLs.
* If the type begins "rl", the data will be copied to a temporary
* file so that seeking is possible (NOT YET IMPLEMENTED).
* Returns a FILE16 for success, NULL for failure.
*/
FILE16 *url_open(const char *url, const char *base, const char *type,
char **merged_url)
{
char *scheme, *host, *path, *m_url;
int port, i;
FILE16 *f;
#ifdef HAVE_LIBZ
int len, gzipped = 0;
#endif
/* Determine the merged URL */
if(!(m_url = url_merge(url, base, &scheme, &host, &port, &path)))
return 0;
#ifdef HAVE_LIBZ
len = strlen(m_url);
if(len > 3 && strcmp8(m_url+len-3, ".gz") == 0)
gzipped = 1;
#endif
/*
printf("<%s> <%s> <%d> <%s>\n", scheme, host ? host : "", port, path);
printf("%s\n", m_url);
*/
/* Pass to the appropriate opening function */
for(i=0; i<NSCHEME; i++)
if(strcmp(scheme, schemes[i].scheme) == 0)
{
f = schemes[i].open(m_url, host, port, path, type);
Free(scheme);
if(host)
Free(host);
Free(path);
if(!f)
return f;
#ifdef HAVE_LIBZ
if(gzipped)
{
/* We have a gzip-compressed file which we hand to gzopen
* for further processing.
*/
gzFile gfile;
FILE *file = GetFILE(f);
if(!f)
{
LT_ERROR1(LEFILE,
"Can't attach gzip processor to URL \"%s\"\n",
m_url);
Free(m_url);
return 0;
}
#ifdef macintosh
gfile =gzdopen(dup(fileno(file)), *type == 'r' ? "rb" : "wb");
#else
gfile = gzdopen(dup(fileno(file)), type);
#endif
Fclose(f);
f = MakeFILE16FromGzip(gfile, type);
}
#endif
if(f && merged_url)
*merged_url = m_url;
else
Free(m_url);
return f;
}
/* Not implemented */
LT_ERROR1(LEFILE, "Error: scheme \"%s\" not implemented\n", scheme);
Free(scheme);
if(host)
Free(host);
Free(path);
Free(m_url);
return 0;
}
/* Open an http URL */
static FILE16 *http_open(const char *url,
const char *host, int port, const char *path,
const char *type)
{
#ifndef SOCKETS_IMPLEMENTED
LT_ERROR(NEUNSUP,
"http: URLs are not yet implemented on this platform\n");
return 0;
#else
FILE16 *f16;
struct sockaddr_in addr;
struct hostent *hostent;
int s, server_major, server_minor, status, count, c;
char reason[81];
#ifndef WIN32
FILE *fin,*fout;
#else
static int inited=0;
int i;
static char buf[1024];
if (!inited)
{
WORD version = MAKEWORD(1, 1);
WSADATA wsaData;
int err = WSAStartup(version, &wsaData);
if (err)
{
LT_ERROR(LEFILE, "Error: can't init HTTP interface\n");
return 0;
}
else if(LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion) != 1)
{
LT_ERROR(LEFILE, "Error: wrong version of WINSOCK\n");
WSACleanup();
return 0;
}
inited = 1;
}
#endif
if(*type != 'r')
{
LT_ERROR1(LEFILE, "Error: can't open http URL \"%s\" for writing\n",
url);
return 0;
}
if(!host)
{
LT_ERROR1(LEFILE, "Error: no host part in http URL \"%s\"\n", url);
return 0;
}
/* Create the socket */
s = socket(PF_INET, SOCK_STREAM, 0);
#ifdef WIN32
if (s == INVALID_SOCKET) {
LT_ERROR1(LEFILE, "Error: system call socket failed: %d\n",
WSAGetLastError());
};
#else
if(s == -1) {
LT_ERROR1(LEFILE, "Error: system call socket failed: %s\n",
Strerror());
return 0;
};
#endif
/* Find the server address */
hostent = gethostbyname(host);
if(!hostent)
{
LT_ERROR1(LEFILE,
"Error: can't find address for host in http URL \"%s\"\n",
url);
return 0;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
/* If we were really enthusiastic, we would try all the host's addresses */
memcpy(&addr.sin_addr, hostent->h_addr, hostent->h_length);
addr.sin_port = htons((u_short)(port == -1 ? 80 : port));
/* Connect */
if(connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
{
LT_ERROR1(LEFILE, "Error: system call connect failed: %s\n",
Strerror());
return 0;
}
#ifndef WIN32
#ifdef macintosh
fin = fdopen(s, "rb");
setvbuf(fin, 0, _IONBF, 0);
fout = fdopen(dup(s), "wb");
#else
fin = fdopen(s, "r");
setvbuf(fin, 0, _IONBF, 0);
fout = fdopen(dup(s), "w");
#endif
#endif
/* Send the request */
/*
* Apparently on the Macintosh, \n might not be ASCII LF, so we'll
* use numerics to be sure.
*/
#ifdef WIN32
sprintf(buf, "GET %s HTTP/1.0\012\015Connection: close\012\015\012\015",
path);
if (send(s,buf,strlen8(buf),0)==SOCKET_ERROR) {
LT_ERROR1(LEFILE, "Error: system call socket failed: %d\n",
WSAGetLastError());
/* XXX close the socket? */
return 0;
};
#else
fprintf(fout, "GET %s HTTP/1.0\012\015Connection: close\012\015\012\015",
path);
/* We used to test for errors after doing fclose, but this seemed
to produce spurious errors under Linux (RedHat 4.2), so now we
do fflush and test after that. */
fflush(fout);
if(ferror(fout))
{
LT_ERROR1(LEWRTF, "Error: write to socket failed: %s\n",Strerror());
fclose(fout);
fclose(fin);
return 0;
}
fclose(fout);
#endif
/* Read the status line */
#ifdef WIN32
for(i=0; i<sizeof(buf)-1; i++)
{
if(recv(s, &buf[i], 1, 0) != 1)
LT_ERROR1(LEFILE,
"Error: recv error from server for URL \"%s\"\n",
url);
if(buf[i] == '\n')
break;
}
count=sscanf(buf, "HTTP/%d.%d %d %80[^\012]",
&server_major, &server_minor, &status, reason);
#else
count=fscanf(fin, "HTTP/%d.%d %d %80[^\012]",
&server_major, &server_minor, &status, reason);
#endif
if(count != 4)
{
LT_ERROR3(LEFILE,
"Error: bad header from server for URL \"%s\"\n%d %s\n",
url, count, Strerror());
#ifndef WIN32
fclose(fin);
#endif
return 0;
}
if(status != 200)
{
/* We should handle 301 (redirection) but we don't */
LT_ERROR3(LEFILE, "Error: can't retrieve \"%s\": %d %s\n",
url, status, reason);
#ifndef WIN32
fclose(fin);
#endif
return 0;
}
/* Skip other headers */
count = 0;
#ifdef WIN32
while(recv(s, buf, 1, 0) == 1 && (c = buf[0], 1) || (c = EOF, 0))
#else
while((c = getc(fin)) != EOF)
#endif
{
if(c == '\012')
count++;
else if(c != '\015')
count = 0;
if(count == 2)
break;
}
if(c == EOF)
{
LT_ERROR1(LEFILE, "Error: EOF in headers retrieving \"%s\"\n", url);
#ifndef WIN32
fclose(fin);
#endif
return 0;
}
#ifdef WIN32
f16 = MakeFILE16FromWinsock(s, type);
#else
f16 = MakeFILE16FromFILE(fin, type);
#endif
SetCloseUnderlying(f16, 1);
return f16;
#endif /* SOCKETS_IMPLEMENTED */
}
/* Open a file URL (easy, at least on unix) */
static FILE16 *file_open(const char *url,
const char *host, int port, const char *path,
const char *type)
{
FILE *f;
FILE16 *f16;
char *file;
if(host && host[0])
WARN1(LEFILE, "Warning: ignoring host part in file URL \"%s\"\n", url);
#ifdef WIN32
/* DOS: translate /C:/a/b.c to C:\a\b.c */
if(path[0] == '/' && path[1] && path[2] == ':')
path++;
file = strdup8(path);
{
char *p;
for(p=file; *p; p++)
if(*p == '/')
*p = '\\';
}
#else
#ifdef mac_filenames
/* Mac: translate /a/b.c to a:b.c */
if(*path == '/')
path++;
file = strdup8(path);
{
char *p;
for(p=file; *p; p++)
if(*p == '/')
*p = ':';
}
#else
/* Unix: a path is a path is a path! */
file = strdup8(path);
#endif
#endif
/* XXX should undo any escapes */
f = fopen(file, type);
if(!f)
{
perror(file);
Free(file);
return 0;
}
Free(file);
f16 = MakeFILE16FromFILE(f, type);
SetCloseUnderlying(f16, 1);
return f16;
}
static void parse_url(const char *url,
char **scheme, char **host, int *port, char **path)
{
char *p, *q;
int warned = 0;
*scheme = *host = *path = 0;
*port = -1;
/* Does it start with a scheme? */
for(p = (char *)url; *p; p++)
if(*p == ':' || *p == '/')
break;
if(p > url && *p == ':')
{
*scheme = Malloc(p - url + 1);
strncpy(*scheme, url, p - url);
(*scheme)[p - url] = '\0';
url = p+1;
}
/* Does it have a net_loc? */
if(url[0] == '/' && url[1] == '/')
{
url += 2;
for(p = (char *)url; *p; p++)
if(*p == '/')
break;
/* Does it have a port number? */
for(q = p-1; q >= url; q--)
if(!isdigit((int)*q))
break;
if(q < p-1 && *q == ':')
*port = atoi(q+1);
else
q = p;
*host = Malloc(q - url + 1);
strncpy(*host, url, q - url);
(*host)[q - url] = '\0';
url = p;
}
/* The rest is the path */
if(*url)
*path = strdup8(url);
else
*path = strdup8("/");
/* Windoze users have a tendency to use backslashes instead of slashes */
for(p=*path; *p; p++)
if(*p == '\\')
{
if(!warned)
{
WARN1(LEFILE, "Warning: illegal backslashes in URL path \"%s\""
"replaced by slashes\n", url);
warned = 1;
}
*p = '/';
}
}