ponymap/plugins/http.c

188 lines
4.7 KiB
C

/*
* http.c: HTTP service detection plugin
*
* Copyright (c) 2014, Přemysl Eric Janouch <p@janouch.name>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include "config.h"
#include "../liberty/liberty.c"
#include "../plugin-api.h"
#include "../http-parser/http_parser.h"
// --- Service detection -------------------------------------------------------
static struct plugin_data
{
void *ctx; ///< Application context
struct plugin_api *api; ///< Plugin API vtable
}
g_data;
enum header_state
{
STATE_FIELD, ///< We've been parsing a field so far
STATE_VALUE ///< We've been parsing a value so far
};
struct scan_data
{
struct unit *u; ///< Scan unit
http_parser parser; ///< HTTP parser
enum header_state state; ///< What did we get last time?
struct str field; ///< Field part buffer
struct str value; ///< Value part buffer
};
static void
on_header_read (struct scan_data *scan)
{
if (!strcasecmp_ascii (scan->field.str, "Server"))
{
char *info = xstrdup_printf ("%s: %s",
"server software", scan->value.str);
g_data.api->unit_add_info (scan->u, info);
free (info);
}
}
static int
on_header_field (http_parser *parser, const char *at, size_t len)
{
struct scan_data *scan = parser->data;
if (scan->state == STATE_VALUE)
{
on_header_read (scan);
str_reset (&scan->field);
str_reset (&scan->value);
}
str_append_data (&scan->field, at, len);
scan->state = STATE_FIELD;
return 0;
}
static int
on_header_value (http_parser *parser, const char *at, size_t len)
{
struct scan_data *data = parser->data;
str_append_data (&data->value, at, len);
data->state = STATE_VALUE;
return 0;
}
static int
on_headers_complete (http_parser *parser)
{
struct scan_data *scan = parser->data;
if (scan->state == STATE_VALUE)
on_header_read (scan);
// We've got this far, this must be an HTTP server
g_data.api->unit_set_success (scan->u, true);
g_data.api->unit_stop (scan->u);
return 1;
}
static void *
scan_init (struct service *service, struct unit *u)
{
(void) service;
struct str hello = str_make ();
str_append_printf (&hello, "GET / HTTP/1.0\r\n"
"Host: %s\r\n\r\n", g_data.api->unit_get_address (u));
g_data.api->unit_write (u, hello.str, hello.len);
str_free (&hello);
struct scan_data *scan = xcalloc (1, sizeof *scan);
http_parser_init (&scan->parser, HTTP_RESPONSE);
scan->parser.data = scan;
scan->state = STATE_FIELD;
scan->field = str_make ();
scan->value = str_make ();
scan->u = u;
return scan;
}
static void
scan_free (void *handle)
{
struct scan_data *scan = handle;
str_free (&scan->field);
str_free (&scan->value);
free (scan);
}
static void
on_data (void *handle, const void *data, size_t len)
{
static const http_parser_settings http_settings =
{
.on_header_field = on_header_field,
.on_header_value = on_header_value,
.on_headers_complete = on_headers_complete,
};
struct scan_data *scan = handle;
http_parser *parser = &scan->parser;
size_t n_parsed = http_parser_execute (parser, &http_settings, data, len);
if (parser->upgrade)
{
// We should never get here though because `on_headers_complete'
// is called first and ends up stopping the unit.
g_data.api->unit_add_info (scan->u, "upgrades to a different protocol");
g_data.api->unit_stop (scan->u);
}
else if (n_parsed != len && parser->http_errno != HPE_CB_headers_complete)
g_data.api->unit_stop (scan->u);
}
static void
on_eof (void *handle)
{
on_data (handle, NULL, 0);
}
static struct service g_http_service =
{
.name = "HTTP",
.flags = SERVICE_SUPPORTS_TLS,
.scan_init = scan_init,
.scan_free = scan_free,
.on_data = on_data,
.on_eof = on_eof,
.on_error = NULL,
.on_stopped = NULL
};
static bool
initialize (void *ctx, struct plugin_api *api)
{
g_data = (struct plugin_data) { .ctx = ctx, .api = api };
api->register_service (ctx, &g_http_service);
return true;
}
struct plugin_info ponymap_plugin_info =
{
.api_version = API_VERSION,
.initialize = initialize
};