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curl/lib/altsvc.c
Daniel Stenberg f93455eb04
altsvc: clone setting in curl_easy_duphandle
The cache content is not duplicated, like other caches, but the setting
and specified file name are.

Test 1908 is extended to verify this somewhat. Since the duplicated
handle gets the same file name, the test unfortunately overwrites the
same file twice (with different contents) which makes it hard to check
automatically.

Closes #5923
2020-09-06 09:54:54 +02:00

646 lines
18 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2019 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
/*
* The Alt-Svc: header is defined in RFC 7838:
* https://tools.ietf.org/html/rfc7838
*/
#include "curl_setup.h"
#if !defined(CURL_DISABLE_HTTP) && defined(USE_ALTSVC)
#include <curl/curl.h>
#include "urldata.h"
#include "altsvc.h"
#include "curl_get_line.h"
#include "strcase.h"
#include "parsedate.h"
#include "sendf.h"
#include "warnless.h"
#include "rand.h"
#include "rename.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
#define MAX_ALTSVC_LINE 4095
#define MAX_ALTSVC_DATELENSTR "64"
#define MAX_ALTSVC_DATELEN 64
#define MAX_ALTSVC_HOSTLENSTR "512"
#define MAX_ALTSVC_HOSTLEN 512
#define MAX_ALTSVC_ALPNLENSTR "10"
#define MAX_ALTSVC_ALPNLEN 10
#if defined(USE_QUICHE) && !defined(UNITTESTS)
#define H3VERSION "h3-29"
#elif defined(USE_NGTCP2) && !defined(UNITTESTS)
#define H3VERSION "h3-29"
#else
#define H3VERSION "h3"
#endif
static enum alpnid alpn2alpnid(char *name)
{
if(strcasecompare(name, "h1"))
return ALPN_h1;
if(strcasecompare(name, "h2"))
return ALPN_h2;
if(strcasecompare(name, H3VERSION))
return ALPN_h3;
return ALPN_none; /* unknown, probably rubbish input */
}
/* Given the ALPN ID, return the name */
const char *Curl_alpnid2str(enum alpnid id)
{
switch(id) {
case ALPN_h1:
return "h1";
case ALPN_h2:
return "h2";
case ALPN_h3:
return H3VERSION;
default:
return ""; /* bad */
}
}
static void altsvc_free(struct altsvc *as)
{
free(as->src.host);
free(as->dst.host);
free(as);
}
static struct altsvc *altsvc_createid(const char *srchost,
const char *dsthost,
enum alpnid srcalpnid,
enum alpnid dstalpnid,
unsigned int srcport,
unsigned int dstport)
{
struct altsvc *as = calloc(sizeof(struct altsvc), 1);
if(!as)
return NULL;
as->src.host = strdup(srchost);
if(!as->src.host)
goto error;
as->dst.host = strdup(dsthost);
if(!as->dst.host)
goto error;
as->src.alpnid = srcalpnid;
as->dst.alpnid = dstalpnid;
as->src.port = curlx_ultous(srcport);
as->dst.port = curlx_ultous(dstport);
return as;
error:
altsvc_free(as);
return NULL;
}
static struct altsvc *altsvc_create(char *srchost,
char *dsthost,
char *srcalpn,
char *dstalpn,
unsigned int srcport,
unsigned int dstport)
{
enum alpnid dstalpnid = alpn2alpnid(dstalpn);
enum alpnid srcalpnid = alpn2alpnid(srcalpn);
if(!srcalpnid || !dstalpnid)
return NULL;
return altsvc_createid(srchost, dsthost, srcalpnid, dstalpnid,
srcport, dstport);
}
/* only returns SERIOUS errors */
static CURLcode altsvc_add(struct altsvcinfo *asi, char *line)
{
/* Example line:
h2 example.com 443 h3 shiny.example.com 8443 "20191231 10:00:00" 1
*/
char srchost[MAX_ALTSVC_HOSTLEN + 1];
char dsthost[MAX_ALTSVC_HOSTLEN + 1];
char srcalpn[MAX_ALTSVC_ALPNLEN + 1];
char dstalpn[MAX_ALTSVC_ALPNLEN + 1];
char date[MAX_ALTSVC_DATELEN + 1];
unsigned int srcport;
unsigned int dstport;
unsigned int prio;
unsigned int persist;
int rc;
rc = sscanf(line,
"%" MAX_ALTSVC_ALPNLENSTR "s %" MAX_ALTSVC_HOSTLENSTR "s %u "
"%" MAX_ALTSVC_ALPNLENSTR "s %" MAX_ALTSVC_HOSTLENSTR "s %u "
"\"%" MAX_ALTSVC_DATELENSTR "[^\"]\" %u %u",
srcalpn, srchost, &srcport,
dstalpn, dsthost, &dstport,
date, &persist, &prio);
if(9 == rc) {
struct altsvc *as;
time_t expires = Curl_getdate_capped(date);
as = altsvc_create(srchost, dsthost, srcalpn, dstalpn, srcport, dstport);
if(as) {
as->expires = expires;
as->prio = prio;
as->persist = persist ? 1 : 0;
Curl_llist_insert_next(&asi->list, asi->list.tail, as, &as->node);
}
}
return CURLE_OK;
}
/*
* Load alt-svc entries from the given file. The text based line-oriented file
* format is documented here:
* https://github.com/curl/curl/wiki/QUIC-implementation
*
* This function only returns error on major problems that prevents alt-svc
* handling to work completely. It will ignore individual syntactical errors
* etc.
*/
static CURLcode altsvc_load(struct altsvcinfo *asi, const char *file)
{
CURLcode result = CURLE_OK;
char *line = NULL;
FILE *fp;
/* we need a private copy of the file name so that the altsvc cache file
name survives an easy handle reset */
free(asi->filename);
asi->filename = strdup(file);
if(!asi->filename)
return CURLE_OUT_OF_MEMORY;
fp = fopen(file, FOPEN_READTEXT);
if(fp) {
line = malloc(MAX_ALTSVC_LINE);
if(!line)
goto fail;
while(Curl_get_line(line, MAX_ALTSVC_LINE, fp)) {
char *lineptr = line;
while(*lineptr && ISBLANK(*lineptr))
lineptr++;
if(*lineptr == '#')
/* skip commented lines */
continue;
altsvc_add(asi, lineptr);
}
free(line); /* free the line buffer */
fclose(fp);
}
return result;
fail:
Curl_safefree(asi->filename);
free(line);
fclose(fp);
return CURLE_OUT_OF_MEMORY;
}
/*
* Write this single altsvc entry to a single output line
*/
static CURLcode altsvc_out(struct altsvc *as, FILE *fp)
{
struct tm stamp;
CURLcode result = Curl_gmtime(as->expires, &stamp);
if(result)
return result;
fprintf(fp,
"%s %s %u "
"%s %s %u "
"\"%d%02d%02d "
"%02d:%02d:%02d\" "
"%u %d\n",
Curl_alpnid2str(as->src.alpnid), as->src.host, as->src.port,
Curl_alpnid2str(as->dst.alpnid), as->dst.host, as->dst.port,
stamp.tm_year + 1900, stamp.tm_mon + 1, stamp.tm_mday,
stamp.tm_hour, stamp.tm_min, stamp.tm_sec,
as->persist, as->prio);
return CURLE_OK;
}
/* ---- library-wide functions below ---- */
/*
* Curl_altsvc_init() creates a new altsvc cache.
* It returns the new instance or NULL if something goes wrong.
*/
struct altsvcinfo *Curl_altsvc_init(void)
{
struct altsvcinfo *asi = calloc(sizeof(struct altsvcinfo), 1);
if(!asi)
return NULL;
Curl_llist_init(&asi->list, NULL);
/* set default behavior */
asi->flags = CURLALTSVC_H1
#ifdef USE_NGHTTP2
| CURLALTSVC_H2
#endif
#ifdef ENABLE_QUIC
| CURLALTSVC_H3
#endif
;
return asi;
}
/*
* Curl_altsvc_load() loads alt-svc from file.
*/
CURLcode Curl_altsvc_load(struct altsvcinfo *asi, const char *file)
{
CURLcode result;
DEBUGASSERT(asi);
result = altsvc_load(asi, file);
return result;
}
/*
* Curl_altsvc_ctrl() passes on the external bitmask.
*/
CURLcode Curl_altsvc_ctrl(struct altsvcinfo *asi, const long ctrl)
{
DEBUGASSERT(asi);
if(!ctrl)
/* unexpected */
return CURLE_BAD_FUNCTION_ARGUMENT;
asi->flags = ctrl;
return CURLE_OK;
}
/*
* Curl_altsvc_cleanup() frees an altsvc cache instance and all associated
* resources.
*/
void Curl_altsvc_cleanup(struct altsvcinfo **altsvcp)
{
struct Curl_llist_element *e;
struct Curl_llist_element *n;
if(*altsvcp) {
struct altsvcinfo *altsvc = *altsvcp;
for(e = altsvc->list.head; e; e = n) {
struct altsvc *as = e->ptr;
n = e->next;
altsvc_free(as);
}
free(altsvc->filename);
free(altsvc);
*altsvcp = NULL; /* clear the pointer */
}
}
/*
* Curl_altsvc_save() writes the altsvc cache to a file.
*/
CURLcode Curl_altsvc_save(struct Curl_easy *data,
struct altsvcinfo *altsvc, const char *file)
{
struct Curl_llist_element *e;
struct Curl_llist_element *n;
CURLcode result = CURLE_OK;
FILE *out;
char *tempstore;
unsigned char randsuffix[9];
if(!altsvc)
/* no cache activated */
return CURLE_OK;
/* if not new name is given, use the one we stored from the load */
if(!file && altsvc->filename)
file = altsvc->filename;
if((altsvc->flags & CURLALTSVC_READONLYFILE) || !file || !file[0])
/* marked as read-only, no file or zero length file name */
return CURLE_OK;
if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
return CURLE_FAILED_INIT;
tempstore = aprintf("%s.%s.tmp", file, randsuffix);
if(!tempstore)
return CURLE_OUT_OF_MEMORY;
out = fopen(tempstore, FOPEN_WRITETEXT);
if(!out)
result = CURLE_WRITE_ERROR;
else {
fputs("# Your alt-svc cache. https://curl.haxx.se/docs/alt-svc.html\n"
"# This file was generated by libcurl! Edit at your own risk.\n",
out);
for(e = altsvc->list.head; e; e = n) {
struct altsvc *as = e->ptr;
n = e->next;
result = altsvc_out(as, out);
if(result)
break;
}
fclose(out);
if(!result && Curl_rename(tempstore, file))
result = CURLE_WRITE_ERROR;
if(result)
unlink(tempstore);
}
free(tempstore);
return result;
}
static CURLcode getalnum(const char **ptr, char *alpnbuf, size_t buflen)
{
size_t len;
const char *protop;
const char *p = *ptr;
while(*p && ISBLANK(*p))
p++;
protop = p;
while(*p && !ISBLANK(*p) && (*p != ';') && (*p != '='))
p++;
len = p - protop;
*ptr = p;
if(!len || (len >= buflen))
return CURLE_BAD_FUNCTION_ARGUMENT;
memcpy(alpnbuf, protop, len);
alpnbuf[len] = 0;
return CURLE_OK;
}
/* altsvc_flush() removes all alternatives for this source origin from the
list */
static void altsvc_flush(struct altsvcinfo *asi, enum alpnid srcalpnid,
const char *srchost, unsigned short srcport)
{
struct Curl_llist_element *e;
struct Curl_llist_element *n;
for(e = asi->list.head; e; e = n) {
struct altsvc *as = e->ptr;
n = e->next;
if((srcalpnid == as->src.alpnid) &&
(srcport == as->src.port) &&
strcasecompare(srchost, as->src.host)) {
Curl_llist_remove(&asi->list, e, NULL);
altsvc_free(as);
}
}
}
#ifdef DEBUGBUILD
/* to play well with debug builds, we can *set* a fixed time this will
return */
static time_t debugtime(void *unused)
{
char *timestr = getenv("CURL_TIME");
(void)unused;
if(timestr) {
unsigned long val = strtol(timestr, NULL, 10);
return (time_t)val;
}
return time(NULL);
}
#define time(x) debugtime(x)
#endif
#define ISNEWLINE(x) (((x) == '\n') || (x) == '\r')
/*
* Curl_altsvc_parse() takes an incoming alt-svc response header and stores
* the data correctly in the cache.
*
* 'value' points to the header *value*. That's contents to the right of the
* header name.
*
* Currently this function rejects invalid data without returning an error.
* Invalid host name, port number will result in the specific alternative
* being rejected. Unknown protocols are skipped.
*/
CURLcode Curl_altsvc_parse(struct Curl_easy *data,
struct altsvcinfo *asi, const char *value,
enum alpnid srcalpnid, const char *srchost,
unsigned short srcport)
{
const char *p = value;
size_t len;
enum alpnid dstalpnid = srcalpnid; /* the same by default */
char namebuf[MAX_ALTSVC_HOSTLEN] = "";
char alpnbuf[MAX_ALTSVC_ALPNLEN] = "";
struct altsvc *as;
unsigned short dstport = srcport; /* the same by default */
CURLcode result = getalnum(&p, alpnbuf, sizeof(alpnbuf));
if(result) {
infof(data, "Excessive alt-svc header, ignoring...\n");
return CURLE_OK;
}
DEBUGASSERT(asi);
/* Flush all cached alternatives for this source origin, if any */
altsvc_flush(asi, srcalpnid, srchost, srcport);
/* "clear" is a magic keyword */
if(strcasecompare(alpnbuf, "clear")) {
return CURLE_OK;
}
do {
if(*p == '=') {
/* [protocol]="[host][:port]" */
dstalpnid = alpn2alpnid(alpnbuf);
p++;
if(*p == '\"') {
const char *dsthost = "";
const char *value_ptr;
char option[32];
unsigned long num;
char *end_ptr;
bool quoted = FALSE;
time_t maxage = 24 * 3600; /* default is 24 hours */
bool persist = FALSE;
p++;
if(*p != ':') {
/* host name starts here */
const char *hostp = p;
while(*p && (ISALNUM(*p) || (*p == '.') || (*p == '-')))
p++;
len = p - hostp;
if(!len || (len >= MAX_ALTSVC_HOSTLEN)) {
infof(data, "Excessive alt-svc host name, ignoring...\n");
dstalpnid = ALPN_none;
}
else {
memcpy(namebuf, hostp, len);
namebuf[len] = 0;
dsthost = namebuf;
}
}
else {
/* no destination name, use source host */
dsthost = srchost;
}
if(*p == ':') {
/* a port number */
unsigned long port = strtoul(++p, &end_ptr, 10);
if(port > USHRT_MAX || end_ptr == p || *end_ptr != '\"') {
infof(data, "Unknown alt-svc port number, ignoring...\n");
dstalpnid = ALPN_none;
}
p = end_ptr;
dstport = curlx_ultous(port);
}
if(*p++ != '\"')
break;
/* Handle the optional 'ma' and 'persist' flags. Unknown flags
are skipped. */
for(;;) {
while(ISBLANK(*p))
p++;
if(*p != ';')
break;
p++; /* pass the semicolon */
if(!*p || ISNEWLINE(*p))
break;
result = getalnum(&p, option, sizeof(option));
if(result) {
/* skip option if name is too long */
option[0] = '\0';
}
while(*p && ISBLANK(*p))
p++;
if(*p != '=')
return CURLE_OK;
p++;
while(*p && ISBLANK(*p))
p++;
if(!*p)
return CURLE_OK;
if(*p == '\"') {
/* quoted value */
p++;
quoted = TRUE;
}
value_ptr = p;
if(quoted) {
while(*p && *p != '\"')
p++;
if(!*p++)
return CURLE_OK;
}
else {
while(*p && !ISBLANK(*p) && *p!= ';' && *p != ',')
p++;
}
num = strtoul(value_ptr, &end_ptr, 10);
if((end_ptr != value_ptr) && (num < ULONG_MAX)) {
if(strcasecompare("ma", option))
maxage = num;
else if(strcasecompare("persist", option) && (num == 1))
persist = TRUE;
}
}
if(dstalpnid) {
as = altsvc_createid(srchost, dsthost,
srcalpnid, dstalpnid,
srcport, dstport);
if(as) {
/* The expires time also needs to take the Age: value (if any) into
account. [See RFC 7838 section 3.1] */
as->expires = maxage + time(NULL);
as->persist = persist;
Curl_llist_insert_next(&asi->list, asi->list.tail, as, &as->node);
infof(data, "Added alt-svc: %s:%d over %s\n", dsthost, dstport,
Curl_alpnid2str(dstalpnid));
}
}
else {
infof(data, "Unknown alt-svc protocol \"%s\", skipping...\n",
alpnbuf);
}
}
else
break;
/* after the double quote there can be a comma if there's another
string or a semicolon if no more */
if(*p == ',') {
/* comma means another alternative is presented */
p++;
result = getalnum(&p, alpnbuf, sizeof(alpnbuf));
if(result)
break;
}
}
else
break;
} while(*p && (*p != ';') && (*p != '\n') && (*p != '\r'));
return CURLE_OK;
}
/*
* Return TRUE on a match
*/
bool Curl_altsvc_lookup(struct altsvcinfo *asi,
enum alpnid srcalpnid, const char *srchost,
int srcport,
struct altsvc **dstentry,
const int versions) /* one or more bits */
{
struct Curl_llist_element *e;
struct Curl_llist_element *n;
time_t now = time(NULL);
DEBUGASSERT(asi);
DEBUGASSERT(srchost);
DEBUGASSERT(dstentry);
for(e = asi->list.head; e; e = n) {
struct altsvc *as = e->ptr;
n = e->next;
if(as->expires < now) {
/* an expired entry, remove */
Curl_llist_remove(&asi->list, e, NULL);
altsvc_free(as);
continue;
}
if((as->src.alpnid == srcalpnid) &&
strcasecompare(as->src.host, srchost) &&
(as->src.port == srcport) &&
(versions & as->dst.alpnid)) {
/* match */
*dstentry = as;
return TRUE;
}
}
return FALSE;
}
#endif /* CURL_DISABLE_HTTP || USE_ALTSVC */