aboutsummaryrefslogtreecommitdiffstats
path: root/lib/altsvc.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/altsvc.c')
-rw-r--r--lib/altsvc.c571
1 files changed, 571 insertions, 0 deletions
diff --git a/lib/altsvc.c b/lib/altsvc.c
new file mode 100644
index 00000000..16434664
--- /dev/null
+++ b/lib/altsvc.c
@@ -0,0 +1,571 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2019, 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 "cookie.h" /* for Curl_get_line() */
+#include "strcase.h"
+#include "parsedate.h"
+#include "sendf.h"
+#include "warnless.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
+
+static enum alpnid alpn2alpnid(char *name)
+{
+ if(strcasecompare(name, "h1"))
+ return ALPN_h1;
+ if(strcasecompare(name, "h2"))
+ return ALPN_h2;
+ if(strcasecompare(name, "h2c"))
+ return ALPN_h2c;
+ if(strcasecompare(name, "h3"))
+ 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_h2c:
+ return "h2c";
+ case ALPN_h3:
+ return "h3";
+ default:
+ return ""; /* bad */
+ }
+}
+
+
+static void altsvc_free(struct altsvc *as)
+{
+ free(as->srchost);
+ free(as->dsthost);
+ 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->srchost = strdup(srchost);
+ if(!as->srchost)
+ goto error;
+ as->dsthost = strdup(dsthost);
+ if(!as->dsthost)
+ goto error;
+
+ as->srcalpnid = srcalpnid;
+ as->dstalpnid = dstalpnid;
+ as->srcport = curlx_ultous(srcport);
+ as->dstport = 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(date, NULL);
+ 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);
+ asi->num++; /* one more entry */
+ }
+ }
+
+ 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 = 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:
+ 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->srcalpnid), as->srchost, as->srcport,
+ Curl_alpnid2str(as->dstalpnid), as->dsthost, as->dstport,
+ 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 USE_HTTP3
+ /* TODO: adjust when known */
+ | 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 *altsvc)
+{
+ struct curl_llist_element *e;
+ struct curl_llist_element *n;
+ if(altsvc) {
+ for(e = altsvc->list.head; e; e = n) {
+ struct altsvc *as = e->ptr;
+ n = e->next;
+ altsvc_free(as);
+ }
+ free(altsvc);
+ }
+}
+
+/*
+ * Curl_altsvc_save() writes the altsvc cache to a file.
+ */
+CURLcode Curl_altsvc_save(struct altsvcinfo *altsvc, const char *file)
+{
+ struct curl_llist_element *e;
+ struct curl_llist_element *n;
+ CURLcode result = CURLE_OK;
+ FILE *out;
+
+ if(!altsvc)
+ /* no cache activated */
+ return CURLE_OK;
+
+ if((altsvc->flags & CURLALTSVC_READONLYFILE) || !file[0])
+ /* marked as read-only or zero length file name */
+ return CURLE_OK;
+ out = fopen(file, FOPEN_WRITETEXT);
+ if(!out)
+ return CURLE_WRITE_ERROR;
+ 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);
+ 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 && ISALNUM(*p))
+ p++;
+ len = p - protop;
+
+ if(!len || (len >= buflen))
+ return CURLE_BAD_FUNCTION_ARGUMENT; /* TODO: improve error code */
+ memcpy(alpnbuf, protop, len);
+ alpnbuf[len] = 0;
+ *ptr = p;
+ 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->srcalpnid) &&
+ (srcport == as->srcport) &&
+ strcasecompare(srchost, as->srchost)) {
+ Curl_llist_remove(&asi->list, e, NULL);
+ altsvc_free(as);
+ asi->num--;
+ }
+ }
+}
+
+#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
+
+/*
+ * 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.
+ */
+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 */
+ const char *semip;
+ time_t maxage = 24 * 3600; /* default is 24 hours */
+ bool persist = FALSE;
+ CURLcode result = getalnum(&p, alpnbuf, sizeof(alpnbuf));
+ if(result)
+ return result;
+
+ 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")) {
+ /* TODO: clear whatever it is it should clear */
+ return CURLE_OK;
+ }
+
+ /* The 'ma' and 'persist' flags are annoyingly meant for all alternatives
+ but are set after the list on the line. Scan for the semicolons and get
+ those fields first! */
+ semip = p;
+ do {
+ semip = strchr(semip, ';');
+ if(semip) {
+ char option[32];
+ unsigned long num;
+ char *end_ptr;
+ semip++; /* pass the semicolon */
+ result = getalnum(&semip, option, sizeof(option));
+ if(result)
+ break;
+ while(*semip && ISBLANK(*semip))
+ semip++;
+ if(*semip != '=')
+ continue;
+ semip++;
+ num = strtoul(semip, &end_ptr, 10);
+ if(num < ULONG_MAX) {
+ if(strcasecompare("ma", option))
+ maxage = num;
+ else if(strcasecompare("persist", option) && (num == 1))
+ persist = TRUE;
+ }
+ semip = end_ptr;
+ }
+ } while(semip);
+
+ do {
+ if(*p == '=') {
+ /* [protocol]="[host][:port]" */
+ dstalpnid = alpn2alpnid(alpnbuf);
+ if(!dstalpnid) {
+ infof(data, "Unknown alt-svc protocol \"%s\", ignoring...\n", alpnbuf);
+ return CURLE_OK;
+ }
+ p++;
+ if(*p == '\"') {
+ const char *dsthost;
+ 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))
+ return CURLE_BAD_FUNCTION_ARGUMENT; /* TODO: improve error code */
+ memcpy(namebuf, hostp, len);
+ namebuf[len] = 0;
+ dsthost = namebuf;
+ }
+ else {
+ /* no destination name, use source host */
+ dsthost = srchost;
+ }
+ if(*p == ':') {
+ /* a port number */
+ char *end_ptr;
+ 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");
+ return CURLE_OK;
+ }
+ p = end_ptr;
+ dstport = curlx_ultous(port);
+ }
+ if(*p++ != '\"')
+ return CURLE_BAD_FUNCTION_ARGUMENT;
+ as = altsvc_createid(srchost, dsthost,
+ srcalpnid, dstalpnid,
+ srcport, dstport);
+ if(as) {
+ /* TODO: 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);
+ asi->num++; /* one more entry */
+ infof(data, "Added alt-svc: %s:%d over %s\n", dsthost, dstport,
+ Curl_alpnid2str(dstalpnid));
+ }
+ }
+ /* 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)
+ /* failed to parse, but since we already did at least one host we
+ return OK */
+ return CURLE_OK;
+ }
+ }
+ } 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,
+ enum alpnid *dstalpnid, const char **dsthost,
+ int *dstport)
+{
+ struct curl_llist_element *e;
+ struct curl_llist_element *n;
+ time_t now = time(NULL);
+ DEBUGASSERT(asi);
+ DEBUGASSERT(srchost);
+ DEBUGASSERT(dsthost);
+
+ for(e = asi->list.head; e; e = n) {
+ struct altsvc *as = e->ptr;
+ n = e->next;
+ if(as->expires < now) {
+ /* an expired entry, remove */
+ altsvc_free(as);
+ continue;
+ }
+ if((as->srcalpnid == srcalpnid) &&
+ strcasecompare(as->srchost, srchost) &&
+ as->srcport == srcport) {
+ /* match */
+ *dstalpnid = as->dstalpnid;
+ *dsthost = as->dsthost;
+ *dstport = as->dstport;
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
+
+#endif /* CURL_DISABLE_HTTP || USE_ALTSVC */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-30 06:17:25 +0000