+/*********************************************************************
+ *
+ * Function : get_char_param
+ *
+ * Description : Get a single-character parameter passed to a CGI
+ * function.
+ *
+ * Parameters :
+ * 1 : parameters = map of cgi parameters
+ * 2 : param_name = The name of the parameter to read
+ *
+ * Returns : Uppercase character on success, '\0' on error.
+ *
+ *********************************************************************/
+char get_char_param(const struct map *parameters,
+ const char *param_name)
+{
+ char ch;
+
+ assert(parameters);
+ assert(param_name);
+
+ ch = *(lookup(parameters, param_name));
+ if ((ch >= 'a') && (ch <= 'z'))
+ {
+ ch = ch - 'a' + 'A';
+ }
+
+ return ch;
+}
+
+
+/*********************************************************************
+ *
+ * Function : get_string_param
+ *
+ * Description : Get a string paramater, to be used as an
+ * ACTION_STRING or ACTION_MULTI paramater.
+ * Validates the input to prevent stupid/malicious
+ * users from corrupting their action file.
+ *
+ * Parameters :
+ * 1 : parameters = map of cgi parameters
+ * 2 : param_name = The name of the parameter to read
+ * 3 : pparam = destination for paramater. Allocated as
+ * part of the map "parameters", so don't free it.
+ * Set to NULL if not specified.
+ *
+ * Returns : JB_ERR_OK on success, or if the paramater
+ * was not specified.
+ * JB_ERR_MEMORY on out-of-memory.
+ * JB_ERR_CGI_PARAMS if the paramater is not valid.
+ *
+ *********************************************************************/
+jb_err get_string_param(const struct map *parameters,
+ const char *param_name,
+ const char **pparam)
+{
+ const char *param;
+ const char *s;
+ char ch;
+
+ assert(parameters);
+ assert(param_name);
+ assert(pparam);
+
+ *pparam = NULL;
+
+ param = lookup(parameters, param_name);
+ if (!*param)
+ {
+ return JB_ERR_OK;
+ }
+
+ if (strlen(param) >= CGI_PARAM_LEN_MAX)
+ {
+ /*
+ * Too long.
+ *
+ * Note that the length limit is arbitrary, it just seems
+ * sensible to limit it to *something*. There's no
+ * technical reason for any limit at all.
+ */
+ return JB_ERR_CGI_PARAMS;
+ }
+
+ /* Check every character to see if it's legal */
+ s = param;
+ while ((ch = *s++) != '\0')
+ {
+ if ( ((unsigned char)ch < (unsigned char)' ')
+ || (ch == '}') )
+ {
+ /* Probable hack attempt, or user accidentally used '}'. */
+ return JB_ERR_CGI_PARAMS;
+ }
+ }
+
+ /* Success */
+ *pparam = param;
+
+ return JB_ERR_OK;
+}
+
+
+/*********************************************************************
+ *
+ * Function : get_number_param
+ *
+ * Description : Get a non-negative integer from the parameters
+ * passed to a CGI function.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : parameters = map of cgi parameters
+ * 3 : name = Name of CGI parameter to read
+ * 4 : pvalue = destination for value.
+ * Set to -1 on error.
+ *
+ * Returns : JB_ERR_OK on success
+ * JB_ERR_MEMORY on out-of-memory
+ * JB_ERR_CGI_PARAMS if the parameter was not specified
+ * or is not valid.
+ *
+ *********************************************************************/
+jb_err get_number_param(struct client_state *csp,
+ const struct map *parameters,
+ char *name,
+ unsigned *pvalue)
+{
+ const char *param;
+ char ch;
+ unsigned value;
+
+ assert(csp);
+ assert(parameters);
+ assert(name);
+ assert(pvalue);
+
+ *pvalue = 0;
+
+ param = lookup(parameters, name);
+ if (!*param)
+ {
+ return JB_ERR_CGI_PARAMS;
+ }
+
+ /* We don't use atoi because I want to check this carefully... */
+
+ value = 0;
+ while ((ch = *param++) != '\0')
+ {
+ if ((ch < '0') || (ch > '9'))
+ {
+ return JB_ERR_CGI_PARAMS;
+ }
+
+ ch -= '0';
+
+ /* Note:
+ *
+ * <limits.h> defines UINT_MAX
+ *
+ * (UINT_MAX - ch) / 10 is the largest number that
+ * can be safely multiplied by 10 then have ch added.
+ */
+ if (value > ((UINT_MAX - (unsigned)ch) / 10U))
+ {
+ return JB_ERR_CGI_PARAMS;
+ }
+
+ value = value * 10 + ch;
+ }
+
+ /* Success */
+ *pvalue = value;
+
+ return JB_ERR_OK;
+
+}
+
+