freebsd-dev/lib/libfetch/fetch.c
Dag-Erling Smørgrav 08a49957b3 r308996 broke IP literals by assuming that a colon could only occur as
a separator between host and port, and using strchr() to search for it.
Rewrite fetch_resolve() so it handles bracketed literals correctly, and
remove similar code elsewhere to avoid passing unbracketed literals to
fetch_resolve().  Remove #ifdef INET6 so we still parse IP literals
correctly even if we do not have the ability to connect to them.

While there, fix an off-by-one error which caused HTTP 400 errors to be
misinterpreted as redirects.

PR:		217723
MFC after:	1 week
Reported by:	bapt, bz, cem, ngie
2017-03-17 14:18:52 +00:00

471 lines
11 KiB
C

/*-
* Copyright (c) 1998-2004 Dag-Erling Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/errno.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "fetch.h"
#include "common.h"
auth_t fetchAuthMethod;
int fetchLastErrCode;
char fetchLastErrString[MAXERRSTRING];
int fetchTimeout;
int fetchRestartCalls = 1;
int fetchDebug;
/*** Local data **************************************************************/
/*
* Error messages for parser errors
*/
#define URL_MALFORMED 1
#define URL_BAD_SCHEME 2
#define URL_BAD_PORT 3
static struct fetcherr url_errlist[] = {
{ URL_MALFORMED, FETCH_URL, "Malformed URL" },
{ URL_BAD_SCHEME, FETCH_URL, "Invalid URL scheme" },
{ URL_BAD_PORT, FETCH_URL, "Invalid server port" },
{ -1, FETCH_UNKNOWN, "Unknown parser error" }
};
/*** Public API **************************************************************/
/*
* Select the appropriate protocol for the URL scheme, and return a
* read-only stream connected to the document referenced by the URL.
* Also fill out the struct url_stat.
*/
FILE *
fetchXGet(struct url *URL, struct url_stat *us, const char *flags)
{
if (us != NULL) {
us->size = -1;
us->atime = us->mtime = 0;
}
if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
return (fetchXGetFile(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
return (fetchXGetFTP(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
return (fetchXGetHTTP(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
return (fetchXGetHTTP(URL, us, flags));
url_seterr(URL_BAD_SCHEME);
return (NULL);
}
/*
* Select the appropriate protocol for the URL scheme, and return a
* read-only stream connected to the document referenced by the URL.
*/
FILE *
fetchGet(struct url *URL, const char *flags)
{
return (fetchXGet(URL, NULL, flags));
}
/*
* Select the appropriate protocol for the URL scheme, and return a
* write-only stream connected to the document referenced by the URL.
*/
FILE *
fetchPut(struct url *URL, const char *flags)
{
if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
return (fetchPutFile(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
return (fetchPutFTP(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
return (fetchPutHTTP(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
return (fetchPutHTTP(URL, flags));
url_seterr(URL_BAD_SCHEME);
return (NULL);
}
/*
* Select the appropriate protocol for the URL scheme, and return the
* size of the document referenced by the URL if it exists.
*/
int
fetchStat(struct url *URL, struct url_stat *us, const char *flags)
{
if (us != NULL) {
us->size = -1;
us->atime = us->mtime = 0;
}
if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
return (fetchStatFile(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
return (fetchStatFTP(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
return (fetchStatHTTP(URL, us, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
return (fetchStatHTTP(URL, us, flags));
url_seterr(URL_BAD_SCHEME);
return (-1);
}
/*
* Select the appropriate protocol for the URL scheme, and return a
* list of files in the directory pointed to by the URL.
*/
struct url_ent *
fetchList(struct url *URL, const char *flags)
{
if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
return (fetchListFile(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
return (fetchListFTP(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
return (fetchListHTTP(URL, flags));
else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
return (fetchListHTTP(URL, flags));
url_seterr(URL_BAD_SCHEME);
return (NULL);
}
/*
* Attempt to parse the given URL; if successful, call fetchXGet().
*/
FILE *
fetchXGetURL(const char *URL, struct url_stat *us, const char *flags)
{
struct url *u;
FILE *f;
if ((u = fetchParseURL(URL)) == NULL)
return (NULL);
f = fetchXGet(u, us, flags);
fetchFreeURL(u);
return (f);
}
/*
* Attempt to parse the given URL; if successful, call fetchGet().
*/
FILE *
fetchGetURL(const char *URL, const char *flags)
{
return (fetchXGetURL(URL, NULL, flags));
}
/*
* Attempt to parse the given URL; if successful, call fetchPut().
*/
FILE *
fetchPutURL(const char *URL, const char *flags)
{
struct url *u;
FILE *f;
if ((u = fetchParseURL(URL)) == NULL)
return (NULL);
f = fetchPut(u, flags);
fetchFreeURL(u);
return (f);
}
/*
* Attempt to parse the given URL; if successful, call fetchStat().
*/
int
fetchStatURL(const char *URL, struct url_stat *us, const char *flags)
{
struct url *u;
int s;
if ((u = fetchParseURL(URL)) == NULL)
return (-1);
s = fetchStat(u, us, flags);
fetchFreeURL(u);
return (s);
}
/*
* Attempt to parse the given URL; if successful, call fetchList().
*/
struct url_ent *
fetchListURL(const char *URL, const char *flags)
{
struct url *u;
struct url_ent *ue;
if ((u = fetchParseURL(URL)) == NULL)
return (NULL);
ue = fetchList(u, flags);
fetchFreeURL(u);
return (ue);
}
/*
* Make a URL
*/
struct url *
fetchMakeURL(const char *scheme, const char *host, int port, const char *doc,
const char *user, const char *pwd)
{
struct url *u;
if (!scheme || (!host && !doc)) {
url_seterr(URL_MALFORMED);
return (NULL);
}
if (port < 0 || port > 65535) {
url_seterr(URL_BAD_PORT);
return (NULL);
}
/* allocate struct url */
if ((u = calloc(1, sizeof(*u))) == NULL) {
fetch_syserr();
return (NULL);
}
if ((u->doc = strdup(doc ? doc : "/")) == NULL) {
fetch_syserr();
free(u);
return (NULL);
}
#define seturl(x) snprintf(u->x, sizeof(u->x), "%s", x)
seturl(scheme);
seturl(host);
seturl(user);
seturl(pwd);
#undef seturl
u->port = port;
u->netrcfd = -2;
return (u);
}
/*
* Return value of the given hex digit.
*/
static int
fetch_hexval(char ch)
{
if (ch >= '0' && ch <= '9')
return (ch - '0');
else if (ch >= 'a' && ch <= 'f')
return (ch - 'a' + 10);
else if (ch >= 'A' && ch <= 'F')
return (ch - 'A' + 10);
return (-1);
}
/*
* Decode percent-encoded URL component from src into dst, stopping at end
* of string, or at @ or : separators. Returns a pointer to the unhandled
* part of the input string (null terminator, @, or :). No terminator is
* written to dst (it is the caller's responsibility).
*/
static const char *
fetch_pctdecode(char *dst, const char *src, size_t dlen)
{
int d1, d2;
char c;
const char *s;
for (s = src; *s != '\0' && *s != '@' && *s != ':'; s++) {
if (s[0] == '%' && (d1 = fetch_hexval(s[1])) >= 0 &&
(d2 = fetch_hexval(s[2])) >= 0 && (d1 > 0 || d2 > 0)) {
c = d1 << 4 | d2;
s += 2;
} else {
c = *s;
}
if (dlen-- > 0)
*dst++ = c;
}
return (s);
}
/*
* Split an URL into components. URL syntax is:
* [method:/][/[user[:pwd]@]host[:port]/][document]
* This almost, but not quite, RFC1738 URL syntax.
*/
struct url *
fetchParseURL(const char *URL)
{
char *doc;
const char *p, *q;
struct url *u;
int i;
/* allocate struct url */
if ((u = calloc(1, sizeof(*u))) == NULL) {
fetch_syserr();
return (NULL);
}
u->netrcfd = -2;
/* scheme name */
if ((p = strstr(URL, ":/"))) {
snprintf(u->scheme, URL_SCHEMELEN+1,
"%.*s", (int)(p - URL), URL);
URL = ++p;
/*
* Only one slash: no host, leave slash as part of document
* Two slashes: host follows, strip slashes
*/
if (URL[1] == '/')
URL = (p += 2);
} else {
p = URL;
}
if (!*URL || *URL == '/' || *URL == '.' ||
(u->scheme[0] == '\0' &&
strchr(URL, '/') == NULL && strchr(URL, ':') == NULL))
goto nohost;
p = strpbrk(URL, "/@");
if (p && *p == '@') {
/* username */
q = fetch_pctdecode(u->user, URL, URL_USERLEN);
/* password */
if (*q == ':')
q = fetch_pctdecode(u->pwd, q + 1, URL_PWDLEN);
p++;
} else {
p = URL;
}
/* hostname */
if (*p == '[' && (q = strchr(p + 1, ']')) != NULL &&
(*++q == '\0' || *q == '/' || *q == ':')) {
if ((i = q - p) > MAXHOSTNAMELEN)
i = MAXHOSTNAMELEN;
strncpy(u->host, p, i);
p = q;
} else {
for (i = 0; *p && (*p != '/') && (*p != ':'); p++)
if (i < MAXHOSTNAMELEN)
u->host[i++] = *p;
}
/* port */
if (*p == ':') {
for (q = ++p; *q && (*q != '/'); q++)
if (isdigit((unsigned char)*q))
u->port = u->port * 10 + (*q - '0');
else {
/* invalid port */
url_seterr(URL_BAD_PORT);
goto ouch;
}
p = q;
}
nohost:
/* document */
if (!*p)
p = "/";
if (strcasecmp(u->scheme, SCHEME_HTTP) == 0 ||
strcasecmp(u->scheme, SCHEME_HTTPS) == 0) {
const char hexnums[] = "0123456789abcdef";
/* percent-escape whitespace. */
if ((doc = malloc(strlen(p) * 3 + 1)) == NULL) {
fetch_syserr();
goto ouch;
}
u->doc = doc;
while (*p != '\0') {
if (!isspace((unsigned char)*p)) {
*doc++ = *p++;
} else {
*doc++ = '%';
*doc++ = hexnums[((unsigned int)*p) >> 4];
*doc++ = hexnums[((unsigned int)*p) & 0xf];
p++;
}
}
*doc = '\0';
} else if ((u->doc = strdup(p)) == NULL) {
fetch_syserr();
goto ouch;
}
DEBUG(fprintf(stderr,
"scheme: \"%s\"\n"
"user: \"%s\"\n"
"password: \"%s\"\n"
"host: \"%s\"\n"
"port: \"%d\"\n"
"document: \"%s\"\n",
u->scheme, u->user, u->pwd,
u->host, u->port, u->doc));
return (u);
ouch:
free(u);
return (NULL);
}
/*
* Free a URL
*/
void
fetchFreeURL(struct url *u)
{
free(u->doc);
free(u);
}