/* Written by Hrvoje Niksic. Parts are loosely inspired by cookie
code submitted by Tomasz Wegrzanowski.
- TODO: Implement limits on cookie-related sizes, such as max. cookie
- size, max. number of cookies, etc. Add more "cookie jar" methods,
- such as methods to over stored cookies, to clear temporary cookies,
- to perform intelligent auto-saving, etc. Ultimately support
- `Set-Cookie2' and `Cookie2' headers. */
+ Ideas for future work:
+
+ * Implement limits on cookie-related sizes, such as max. cookie
+ size, max. number of cookies, etc.
+
+ * Add more "cookie jar" methods, such as methods to iterate over
+ stored cookies, to clear temporary cookies, to perform
+ intelligent auto-saving, etc.
+
+ * Support `Set-Cookie2' and `Cookie2' headers? Does anyone really
+ use them? */
#include <config.h>
\f
/* Declarations of `struct cookie' and the most basic functions. */
+/* Cookie jar serves as cookie storage and a means of retrieving
+ cookies efficiently. All cookies with the same domain are stored
+ in a linked list called "chain". A cookie chain can be reached by
+ looking up the domain in the cookie jar's chains_by_domain table.
+
+ For example, to reach all the cookies under google.com, one must
+ execute hash_table_get(jar->chains_by_domain, "google.com"). Of
+ course, when sending a cookie to `www.google.com', one must search
+ for cookies that belong to either `www.google.com' or `google.com'
+ -- but the point is that the code doesn't need to go through *all*
+ the cookies. */
+
struct cookie_jar {
- /* Hash table that maps domain names to cookie chains. A "cookie
- chain" is a linked list of cookies that belong to the same
- domain. */
+ /* Mapping between domains and their corresponding cookies. */
struct hash_table *chains_by_domain;
int cookie_count; /* number of cookies in the jar. */
}
else
{
- /* We are now creating the chain. Allocate the string that will
- be used as a key. It is unsafe to use cookie->domain for
- that, because it might get deallocated by the above code at
- some point later. */
+ /* We are now creating the chain. Use a copy of cookie->domain
+ as the key for the life-time of the chain. Using
+ cookie->domain would be unsafe because the life-time of the
+ chain may exceed the life-time of the cookie. (Cookies may
+ be deleted from the chain by this very function.) */
cookie->next = NULL;
chain_key = xstrdup (cookie->domain);
}
/* Functions for parsing the `Set-Cookie' header, and creating new
cookies from the wire. */
-
#define NAME_IS(string_literal) \
BOUNDED_EQUAL_NO_CASE (name_b, name_e, string_literal)
DEBUGP ((" 7"));
- /* Don't allow domain "bar.com" to match host "foobar.com". */
+ /* Don't allow the host "foobar.com" to set a cookie for domain
+ "bar.com". */
if (*cookie_domain != '.')
{
int dlen = strlen (cookie_domain);
logprintf (LOG_NOTQUIET,
"Cookie coming from %s attempted to set domain to %s\n",
host, cookie->domain);
+ xfree (cookie->domain);
goto copy_domain;
}
}
+
if (!cookie->path)
cookie->path = xstrdup (path);
else
previously stored cookies. Entry point is
`build_cookies_request'. */
-/* Find the cookie chains that match HOST and store them to DEST.
+/* Find the cookie chains whose domains match HOST and store them to
+ DEST.
- A cookie chain is the list of cookies declared under a domain.
- Given HOST "img.search.xemacs.org", this function will store the
- chains for "img.search.xemacs.org", "search.xemacs.org", and
- "xemacs.org" -- those of them that exist (if any), that is.
+ A cookie chain is the head of a list of cookies that belong to a
+ host/domain. Given HOST "img.search.xemacs.org", this function
+ will return the chains for "img.search.xemacs.org",
+ "search.xemacs.org", and "xemacs.org" -- those of them that exist
+ (if any), that is.
- No more than SIZE matches are written; if more matches are present,
- return the number of chains that would have been written. */
+ DEST should be large enough to accept (in the worst case) as many
+ elements as there are domain components of HOST. */
static int
-find_matching_chains (struct cookie_jar *jar, const char *host,
- struct cookie *dest[], int dest_size)
+find_chains_of_host (struct cookie_jar *jar, const char *host,
+ struct cookie *dest[])
{
int dest_count = 0;
int passes, passcnt;
+ /* Bail out quickly if there are no cookies in the jar. */
if (!hash_table_count (jar->chains_by_domain))
return 0;
{
struct cookie *chain = hash_table_get (jar->chains_by_domain, host);
if (chain)
- {
- if (dest_count < dest_size)
- dest[dest_count] = chain;
- ++dest_count;
- }
+ dest[dest_count++] = chain;
if (++passcnt >= passes)
break;
host = strchr (host, '.') + 1;
if (*prefix != '/')
/* Wget's HTTP paths do not begin with '/' (the URL code treats it
- as a separator), but the '/' is assumed when matching against
- the cookie stuff. */
+ as a mere separator, inspired by rfc1808), but the '/' is
+ assumed when matching against the cookie stuff. */
return 0;
++prefix;
return len + 1;
}
-/* Return non-zero iff COOKIE matches the given HOST, PORT, PATH, and
- SECFLAG.
+/* Return non-zero iff COOKIE matches the provided parameters of the
+ URL being downloaded: HOST, PORT, PATH, and SECFLAG.
If PATH_GOODNESS is non-NULL, store the "path goodness" value
- there. That value is a measure of how well COOKIE matches PATH,
+ there. That value is a measure of how closely COOKIE matches PATH,
used for ordering cookies. */
static int
-matching_cookie (const struct cookie *cookie,
- const char *host, int port, const char *path,
- int secure, int *path_goodness)
+cookie_matches_url (const struct cookie *cookie,
+ const char *host, int port, const char *path,
+ int secflag, int *path_goodness)
{
int pg;
possible. */
return 0;
- if (cookie->secure && !secure)
+ if (cookie->secure && !secflag)
/* Don't transmit secure cookies over insecure connections. */
return 0;
if (cookie->port != PORT_ANY && cookie->port != port)
/* If exact domain match is required, verify that cookie's domain is
equal to HOST. If not, assume success on the grounds of the
- cookie's chain having been found by find_matching_chains. */
+ cookie's chain having been found by find_chains_of_host. */
if (cookie->domain_exact
&& 0 != strcasecmp (host, cookie->domain))
return 0;
}
/* Eliminate duplicate cookies. "Duplicate cookies" are any two
- cookies whose name and value are the same. Whenever a duplicate
+ cookies with the same attr name and value. Whenever a duplicate
pair is found, one of the cookies is removed. */
static int
eliminate_dups (struct weighed_cookie *outgoing, int count)
{
- int i;
+ struct weighed_cookie *h; /* hare */
+ struct weighed_cookie *t; /* tortoise */
+ struct weighed_cookie *end = outgoing + count;
/* We deploy a simple uniquify algorithm: first sort the array
- according to our sort criteria, then uniquify it by comparing
- each cookie with its neighbor. */
+ according to our sort criteria, then copy it to itself, comparing
+ each cookie to its neighbor and ignoring the duplicates. */
qsort (outgoing, count, sizeof (struct weighed_cookie), equality_comparator);
- for (i = 0; i < count - 1; i++)
+ /* "Hare" runs through all the entries in the array, followed by
+ "tortoise". If a duplicate is found, the hare skips it.
+ Non-duplicate entries are copied to the tortoise ptr. */
+
+ for (h = t = outgoing; h < end; h++)
{
- struct cookie *c1 = outgoing[i].cookie;
- struct cookie *c2 = outgoing[i + 1].cookie;
- if (!strcmp (c1->attr, c2->attr) && !strcmp (c1->value, c2->value))
+ if (h != end - 1)
{
- /* c1 and c2 are the same; get rid of c2. */
- if (count > i + 1)
- /* move all ptrs from positions [i + 1, count) to i. */
- memmove (outgoing + i, outgoing + i + 1,
- (count - (i + 1)) * sizeof (struct weighed_cookie));
- /* We decrement i to counter the ++i above. Remember that
- we've just removed the element in front of us; we need to
- remain in place to check whether outgoing[i] matches what
- used to be outgoing[i + 2]. */
- --i;
- --count;
+ struct cookie *c0 = h[0].cookie;
+ struct cookie *c1 = h[1].cookie;
+ if (!strcmp (c0->attr, c1->attr) && !strcmp (c0->value, c1->value))
+ continue; /* ignore the duplicate */
}
+
+ /* If the hare has advanced past the tortoise (because of
+ previous dups), make sure the values get copied. Otherwise,
+ no copying is necessary. */
+ if (h != t)
+ *t++ = *h;
+ else
+ t++;
}
- return count;
+ return t - outgoing;
}
/* Comparator used for sorting by quality. */
int port, const char *path,
int connection_secure_p)
{
- struct cookie *chain_default_store[5];
- struct cookie **chains = chain_default_store;
- int chain_store_size = countof (chain_default_store);
+ struct cookie **chains;
int chain_count;
struct cookie *cookie;
char *result;
int result_size, pos;
- /* First, find the chains that match HOST. */
- again:
- chain_count = find_matching_chains (jar, host, chains, chain_store_size);
- if (chain_count > chain_store_size)
- {
- /* It's unlikely that more than 5 chains will ever match. But
- since find_matching_chains reports the exact size it needs,
- it's easy to not have the limitation, so we don't. */
- chains = alloca (chain_count * sizeof (struct cookie *));
- chain_store_size = chain_count;
- goto again;
- }
+ /* First, find the cookie chains whose domains match HOST. */
+
+ /* Allocate room for find_chains_of_host to write to. The number of
+ chains can at most equal the number of subdomains, hence
+ 1+<number of dots>. */
+ chains = alloca_array (struct cookie *, 1 + count_char (host, '.'));
+ chain_count = find_chains_of_host (jar, host, chains);
+ /* No cookies for this host. */
if (!chain_count)
return NULL;
count = 0;
for (i = 0; i < chain_count; i++)
for (cookie = chains[i]; cookie; cookie = cookie->next)
- if (matching_cookie (cookie, host, port, path, connection_secure_p, NULL))
+ if (cookie_matches_url (cookie, host, port, path, connection_secure_p,
+ NULL))
++count;
if (!count)
return NULL; /* no cookies matched */
/* Allocate the array. */
- outgoing = alloca (count * sizeof (struct weighed_cookie));
+ outgoing = alloca_array (struct weighed_cookie, count);
/* Fill the array with all the matching cookies from the chains that
match HOST. */
for (cookie = chains[i]; cookie; cookie = cookie->next)
{
int pg;
- if (!matching_cookie (cookie, host, port, path,
- connection_secure_p, &pg))
+ if (!cookie_matches_url (cookie, host, port, path,
+ connection_secure_p, &pg))
continue;
outgoing[ocnt].cookie = cookie;
outgoing[ocnt].domain_goodness = strlen (cookie->domain);
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