Welcome

From feb9ac1f4cd0fe0d83f6f5ef18c25f059674905a Mon Sep 17 00:00:00 2001 From: "Evgeny Grin (Karlson2k)" Date: Fri, 19 May 2023 13:07:09 +0300 Subject: examples/sessions.c: removed non-portable function and improved safety --- doc/examples/sessions.c | 150 ++++++++++++++++++++++-------------------------- 1 file changed, 69 insertions(+), 81 deletions(-) diff --git a/doc/examples/sessions.c b/doc/examples/sessions.c index de864382..3f60c291 100644 --- a/doc/examples/sessions.c +++ b/doc/examples/sessions.c @@ -6,61 +6,8 @@ #include #include #include -#include #include -/* Emulate 'asprintf()', as it is not portable */ -static int -MHD_asprintf (char **resultp, const char *format, ...) -{ - va_list argptr; - va_list argcopy; - int len; - int ret; - - ret = -1; - va_start (argptr, format); - - va_copy (argcopy, argptr); -#ifndef _WIN32 - len = vsnprintf (NULL, 0, format, argcopy); -#else - len = _vscprintf (format, argcopy); -#endif - va_end (argcopy); - if (0 < len) - { - size_t buf_size; - char *buf; - - buf_size = (size_t) len + 1; - buf = (char *) malloc (buf_size * sizeof(char)); - if (NULL != buf) - { - int res; - -#ifndef _WIN32 - res = vsnprintf (buf, buf_size, format, argptr); -#else - res = _vsnprintf (buf, buf_size, format, argptr); -#endif - if (len == res) - { - *resultp = buf; - ret = res; - } - else - { - free (buf); - *resultp = NULL; - } - } - } - va_end (argptr); - return ret; -} - - /** * Invalid method page. */ @@ -79,12 +26,16 @@ MHD_asprintf (char **resultp, const char *format, ...) #define MAIN_PAGE \ "Welcome

What is your name? " +#define FORM_V1 MAIN_PAGE + /** * Second page. (/2) */ #define SECOND_PAGE \ "Tell me moreprevious %s, what is your job? " +#define FORM_V1_V2 SECOND_PAGE + /** * Second page (/S) */ @@ -350,27 +301,45 @@ fill_v1_form (const void *cls, int reply_len; (void) cls; /* Unused */ - reply_len = MHD_asprintf (&reply, - MAIN_PAGE, - session->value_1); + /* Emulate 'asprintf' */ + reply_len = snprintf (NULL, 0, FORM_V1, session->value_1); if (0 > reply_len) + return MHD_NO; /* Internal error */ + + reply = (char *) malloc (reply_len + 1); + if (NULL == reply) + return MHD_NO; /* Out-of-memory error */ + + if (reply_len != snprintf (reply, + ((size_t) reply_len) + 1, + FORM_V1, + session->value_1)) { - /* oops */ - return MHD_NO; + free (reply); + return MHD_NO; /* printf error */ } + /* return static form */ response = MHD_create_response_from_buffer_with_free_callback ((size_t) reply_len, (void *) reply, &free); - add_session_cookie (session, response); - MHD_add_response_header (response, - MHD_HTTP_HEADER_CONTENT_ENCODING, - mime); - ret = MHD_queue_response (connection, - MHD_HTTP_OK, - response); - MHD_destroy_response (response); + if (NULL != response) + { + add_session_cookie (session, response); + MHD_add_response_header (response, + MHD_HTTP_HEADER_CONTENT_ENCODING, + mime); + ret = MHD_queue_response (connection, + MHD_HTTP_OK, + response); + MHD_destroy_response (response); + } + else + { + free (reply); + ret = MHD_NO; + } return ret; } @@ -395,28 +364,47 @@ fill_v1_v2_form (const void *cls, int reply_len; (void) cls; /* Unused */ - reply_len = MHD_asprintf (&reply, - SECOND_PAGE, - session->value_1, - session->value_2); + /* Emulate 'asprintf' */ + reply_len = snprintf (NULL, 0, FORM_V1_V2, session->value_1, + session->value_2); if (0 > reply_len) + return MHD_NO; /* Internal error */ + + reply = (char *) malloc (reply_len + 1); + if (NULL == reply) + return MHD_NO; /* Out-of-memory error */ + + if (reply_len == snprintf (reply, + ((size_t) reply_len) + 1, + FORM_V1_V2, + session->value_1, + session->value_2)) { - /* oops */ - return MHD_NO; + free (reply); + return MHD_NO; /* printf error */ } + /* return static form */ response = MHD_create_response_from_buffer_with_free_callback ((size_t) reply_len, (void *) reply, &free); - add_session_cookie (session, response); - MHD_add_response_header (response, - MHD_HTTP_HEADER_CONTENT_ENCODING, - mime); - ret = MHD_queue_response (connection, - MHD_HTTP_OK, - response); - MHD_destroy_response (response); + if (NULL != response) + { + add_session_cookie (session, response); + MHD_add_response_header (response, + MHD_HTTP_HEADER_CONTENT_ENCODING, + mime); + ret = MHD_queue_response (connection, + MHD_HTTP_OK, + response); + MHD_destroy_response (response); + } + else + { + free (reply); + ret = MHD_NO; + } return ret; } @@ -457,7 +445,7 @@ not_found_page (const void *cls, /** * List of all pages served by this HTTP server. */ -static struct Page pages[] = { +static const struct Page pages[] = { { "/", "text/html", &fill_v1_form, NULL }, { "/2", "text/html", &fill_v1_v2_form, NULL }, { "/S", "text/html", &serve_simple_form, SUBMIT_PAGE }, -- cgit v1.2.3