urlapi: strip off scope id from numerical IPv6 addresses

... to make the host name "usable". Store the scope id and put it back when extracting a URL out of it. Also makes curl_url_set() syntax check CURLUPART_HOST. Fixes #3817 Closes #3822
2025-02-23 15:10:03 +08:00 · 2019-04-30 16:59:08 +02:00 · 2019-04-30 16:59:08 +02:00 · bdb2dbc103
commit bdb2dbc103
parent 0281262819
5 changed files with 192 additions and 12 deletions
--- a/docs/TODO
+++ b/docs/TODO
@ -35,6 +35,7 @@
 1.16 Try to URL encode given URL
 1.17 Add support for IRIs
 1.18 try next proxy if one doesn't work
+ 1.19 add CURLUPART_SCOPEID
 1.20 SRV and URI DNS records
 1.21 Have the URL API offer IDN decoding
 1.22 CURLINFO_PAUSE_STATE
@ -372,6 +373,11 @@

 https://github.com/curl/curl/issues/896

+1.19 add CURLUPART_SCOPEID
+
+ Add support for CURLUPART_SCOPEID to curl_url_set() and curl_url_get(). It is
+ only really used when the host name is an IPv6 numerical address.
+
 1.20 SRV and URI DNS records

 Offer support for resolving SRV and URI DNS records for libcurl to know which
--- a/lib/urlapi.c
+++ b/lib/urlapi.c
@ -56,6 +56,7 @@ struct Curl_URL {
  char *password;
  char *options; /* IMAP only? */
  char *host;
+  char *scopeid; /* for numerical IPv6 addresses */
  char *port;
  char *path;
  char *query;
@ -74,6 +75,7 @@ static void free_urlhandle(struct Curl_URL *u)
  free(u->password);
  free(u->options);
  free(u->host);
+  free(u->scopeid);
  free(u->port);
  free(u->path);
  free(u->query);
@ -504,7 +506,7 @@ UNITTEST CURLUcode Curl_parse_port(struct Curl_URL *u, char *hostname)
      portptr = &hostname[len];
    else if('%' == endbracket) {
      int zonelen = len;
-      if(1 == sscanf(hostname + zonelen, "25%*[^]]%c%n", &endbracket, &len)) {
+      if(1 == sscanf(hostname + zonelen, "%*[^]]%c%n", &endbracket, &len)) {
        if(']' != endbracket)
          return CURLUE_MALFORMED_INPUT;
        portptr = &hostname[--zonelen + len + 1];
@ -587,25 +589,45 @@ static CURLUcode junkscan(char *part)
  return CURLUE_OK;
 }

-static CURLUcode hostname_check(char *hostname, unsigned int flags)
+static CURLUcode hostname_check(struct Curl_URL *u, char *hostname)
 {
  const char *l = NULL; /* accepted characters */
  size_t len;
  size_t hlen = strlen(hostname);
-  (void)flags;

  if(hostname[0] == '[') {
    hostname++;
-    l = "0123456789abcdefABCDEF::.%";
+    l = "0123456789abcdefABCDEF::.";
    hlen -= 2;
  }

  if(l) {
    /* only valid letters are ok */
    len = strspn(hostname, l);
-    if(hlen != len)
-      /* hostname with bad content */
-      return CURLUE_MALFORMED_INPUT;
+    if(hlen != len) {
+      /* this could now be '%[zone id]' */
+      char scopeid[16];
+      if(hostname[len] == '%') {
+        int i = 0;
+        char *h = &hostname[len + 1];
+        /* pass '25' if present and is a url encoded percent sign */
+        if(!strncmp(h, "25", 2) && h[2] && (h[2] != ']'))
+          h += 2;
+        while(*h && (*h != ']') && (i < 15))
+          scopeid[i++] = *h++;
+        if(!i || (']' != *h))
+          return CURLUE_MALFORMED_INPUT;
+        scopeid[i] = 0;
+        u->scopeid = strdup(scopeid);
+        if(!u->scopeid)
+          return CURLUE_OUT_OF_MEMORY;
+        hostname[len] = ']'; /* insert end bracket */
+        hostname[len + 1] = 0; /* terminate the hostname */
+      }
+      else
+        return CURLUE_MALFORMED_INPUT;
+      /* hostname is fine */
+    }
  }
  else {
    /* letters from the second string is not ok */
@ -856,7 +878,7 @@ static CURLUcode seturl(const char *url, CURLU *u, unsigned int flags)
    if(result)
      return result;

-    result = hostname_check(hostname, flags);
+    result = hostname_check(u, hostname);
    if(result)
      return result;

@ -1021,6 +1043,7 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
    char *scheme;
    char *options = u->options;
    char *port = u->port;
+    char *allochost = NULL;
    if(u->scheme && strcasecompare("file", u->scheme)) {
      url = aprintf("file://%s%s%s",
                    u->path,
@ -1059,6 +1082,18 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
      if(h && !(h->flags & PROTOPT_URLOPTIONS))
        options = NULL;

+      if((u->host[0] == '[') && u->scopeid) {
+        /* make it '[ host %25 scopeid ]' */
+        size_t hostlen = strlen(u->host);
+        size_t alen = hostlen + 3 + strlen(u->scopeid) + 1;
+        allochost = malloc(alen);
+        if(!allochost)
+          return CURLUE_OUT_OF_MEMORY;
+        memcpy(allochost, u->host, hostlen - 1);
+        msnprintf(&allochost[hostlen - 1], alen - hostlen + 1,
+                  "%%25%s]", u->scopeid);
+      }
+
      url = aprintf("%s://%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
                    scheme,
                    u->user ? u->user : "",
@ -1067,7 +1102,7 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
                    options ? ";" : "",
                    options ? options : "",
                    (u->user || u->password || options) ? "@": "",
-                    u->host,
+                    allochost ? allochost : u->host,
                    port ? ":": "",
                    port ? port : "",
                    (u->path && (u->path[0] != '/')) ? "/": "",
@ -1076,6 +1111,7 @@ CURLUcode curl_url_get(CURLU *u, CURLUPart what,
                    (u->query && u->query[0]) ? u->query : "",
                    u->fragment? "#": "",
                    u->fragment? u->fragment : "");
+      free(allochost);
    }
    if(!url)
      return CURLUE_OUT_OF_MEMORY;
@ -1191,6 +1227,8 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
    break;
  case CURLUPART_HOST:
    storep = &u->host;
+    free(u->scopeid);
+    u->scopeid = NULL;
    break;
  case CURLUPART_PORT:
  {
@ -1370,6 +1408,13 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
      }
    }

+    if(what == CURLUPART_HOST) {
+      if(hostname_check(u, (char *)newp)) {
+        free((char *)newp);
+        return CURLUE_MALFORMED_INPUT;
+      }
+    }
+
    free(*storep);
    *storep = (char *)newp;
  }
--- a/tests/data/test1560
+++ b/tests/data/test1560
@ -31,4 +31,14 @@ lib1560
 </tool>
 </client>

+<verify>
+<stdout>
+we got [fe80::20c:29ff:fe9c:409b]
+we got https://[::1]/hello.html
+we got https://example.com/hello.html
+we got https://[fe80::20c:29ff:fe9c:409b%25eth0]/hello.html
+we got [fe80::20c:29ff:fe9c:409b]
+success
+</stdout>
+</verify>
 </testcase>
--- a/tests/libtest/lib1560.c
+++ b/tests/libtest/lib1560.c
@ -153,7 +153,13 @@ static struct testcase get_parts_list[] ={
   "http | [11] | [12] | [13] | [fd00:a41::50] | [15] | / | [16] | [17]",
   CURLU_DEFAULT_SCHEME, 0, CURLUE_OK},
  {"https://[::1%252]:1234",
-   "https | [11] | [12] | [13] | [::1%252] | 1234 | / | [16] | [17]",
+   "https | [11] | [12] | [13] | [::1] | 1234 | / | [16] | [17]",
+   CURLU_DEFAULT_SCHEME, 0, CURLUE_OK},
+
+  /* here's "bad" zone id */
+  {"https://[fe80::20c:29ff:fe9c:409b%eth0]:1234",
+   "https | [11] | [12] | [13] | [fe80::20c:29ff:fe9c:409b] | 1234 "
+   "| / | [16] | [17]",
   CURLU_DEFAULT_SCHEME, 0, CURLUE_OK},
  {"https://127.0.0.1:443",
   "https | [11] | [12] | [13] | 127.0.0.1 | [15] | / | [16] | [17]",
@ -273,6 +279,18 @@ static struct testcase get_parts_list[] ={
 };

 static struct urltestcase get_url_list[] = {
+  {"https://[fe80::20c:29ff:fe9c:409b%]:1234",
+   "",
+   0, 0, CURLUE_MALFORMED_INPUT},
+  {"https://[fe80::20c:29ff:fe9c:409b%25]:1234",
+   "https://[fe80::20c:29ff:fe9c:409b%2525]:1234/",
+   0, 0, CURLUE_OK},
+  {"https://[fe80::20c:29ff:fe9c:409b%eth0]:1234",
+   "https://[fe80::20c:29ff:fe9c:409b%25eth0]:1234/",
+   0, 0, CURLUE_OK},
+  {"https://[::%25fakeit]/moo",
+   "https://[::%25fakeit]/moo",
+   0, 0, CURLUE_OK},
  {"smtp.example.com/path/html",
   "smtp://smtp.example.com/path/html",
   CURLU_GUESS_SCHEME, 0, CURLUE_OK},
@ -831,10 +849,111 @@ static int append(void)
  return error;
 }

+static int scopeid(void)
+{
+  CURLU *u;
+  int error = 0;
+  CURLUcode rc;
+  char *url;
+
+  u = curl_url();
+  rc = curl_url_set(u, CURLUPART_URL,
+                    "https://[fe80::20c:29ff:fe9c:409b%25eth0]/hello.html", 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_set returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+
+  rc = curl_url_get(u, CURLUPART_HOST, &url, 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_get CURLUPART_HOST returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+  else {
+    printf("we got %s\n", url);
+    curl_free(url);
+  }
+
+  rc = curl_url_set(u, CURLUPART_HOST, "[::1]", 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_set CURLUPART_HOST returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+
+  rc = curl_url_get(u, CURLUPART_URL, &url, 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_get CURLUPART_URL returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+  else {
+    printf("we got %s\n", url);
+    curl_free(url);
+  }
+
+  rc = curl_url_set(u, CURLUPART_HOST, "example.com", 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_set CURLUPART_HOST returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+
+  rc = curl_url_get(u, CURLUPART_URL, &url, 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_get CURLUPART_URL returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+  else {
+    printf("we got %s\n", url);
+    curl_free(url);
+  }
+
+  rc = curl_url_set(u, CURLUPART_HOST,
+                    "[fe80::20c:29ff:fe9c:409b%25eth0]", 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_set CURLUPART_HOST returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+
+  rc = curl_url_get(u, CURLUPART_URL, &url, 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_get CURLUPART_URL returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+  else {
+    printf("we got %s\n", url);
+    curl_free(url);
+  }
+
+  rc = curl_url_get(u, CURLUPART_HOST, &url, 0);
+  if(rc != CURLUE_OK) {
+    fprintf(stderr, "%s:%d curl_url_get CURLUPART_HOST returned %d\n",
+            __FILE__, __LINE__, (int)rc);
+    error++;
+  }
+  else {
+    printf("we got %s\n", url);
+    curl_free(url);
+  }
+
+  curl_url_cleanup(u);
+
+  return error;
+}
+
 int test(char *URL)
 {
  (void)URL; /* not used */

+  if(scopeid())
+    return 6;
+
  if(append())
    return 5;

--- a/tests/unit/unit1653.c
+++ b/tests/unit/unit1653.c
@ -168,7 +168,7 @@ UNITTEST_START
  u = curl_url();
  if(!u)
    goto fail;
-  ipv6port = strdup("[fe80::250:56ff:fea7:da15%!25eth3]:80");
+  ipv6port = strdup("[fe80::250:56ff:fea7:da15!25eth3]:80");
  if(!ipv6port)
    goto fail;
  ret = Curl_parse_port(u, ipv6port);
@ -184,7 +184,7 @@ UNITTEST_START
  if(!ipv6port)
    goto fail;
  ret = Curl_parse_port(u, ipv6port);
-  fail_unless(ret != CURLUE_OK, "Curl_parse_port returned non-error");
+  fail_unless(ret == CURLUE_OK, "Curl_parse_port returned error");
  fail:
  free(ipv6port);
  curl_url_cleanup(u);