diff options
Diffstat (limited to 'backend/escl/escl_status.c')
| -rw-r--r-- | backend/escl/escl_status.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/backend/escl/escl_status.c b/backend/escl/escl_status.c new file mode 100644 index 0000000..68b51dc --- /dev/null +++ b/backend/escl/escl_status.c @@ -0,0 +1,176 @@ +/* sane - Scanner Access Now Easy. + + Copyright (C) 2019 Touboul Nathane + Copyright (C) 2019 Thierry HUCHARD <thierry@ordissimo.com> + + This file is part of the SANE package. + + SANE is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + SANE is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + for more details. + + You should have received a copy of the GNU General Public License + along with sane; see the file COPYING. If not, write to the Free + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + + This file implements a SANE backend for eSCL scanners. */ + +#define DEBUG_DECLARE_ONLY +#include "../include/sane/config.h" + +#include "escl.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <curl/curl.h> +#include <libxml/parser.h> + +struct idle +{ + char *memory; + size_t size; +}; + +/** + * \fn static size_t memory_callback_s(void *contents, size_t size, size_t nmemb, void *userp) + * \brief Callback function that stocks in memory the content of the scanner status. + * + * \return realsize (size of the content needed -> the scanner status) + */ +static size_t +memory_callback_s(void *contents, size_t size, size_t nmemb, void *userp) +{ + size_t realsize = size * nmemb; + struct idle *mem = (struct idle *)userp; + + char *str = realloc(mem->memory, mem->size + realsize + 1); + if (str == NULL) { + DBG(1, "not enough memory (realloc returned NULL)\n"); + return (0); + } + mem->memory = str; + memcpy(&(mem->memory[mem->size]), contents, realsize); + mem->size = mem->size + realsize; + mem->memory[mem->size] = 0; + return (realsize); +} + +/** + * \fn static int find_nodes_s(xmlNode *node) + * \brief Function that browses the xml file and parses it, to find the xml children node. + * --> to recover the scanner status. + * + * \return 0 if a xml child node is found, 1 otherwise + */ +static int +find_nodes_s(xmlNode *node) +{ + xmlNode *child = node->children; + + while (child) { + if (child->type == XML_ELEMENT_NODE) + return (0); + child = child->next; + } + return (1); +} + +/** + * \fn static void print_xml_s(xmlNode *node, SANE_Status *status) + * \brief Function that browses the xml file, node by node. + * If the node 'State' is found, we are expecting to found in this node the 'Idle' + * content (if the scanner is ready to use) and then 'status' = SANE_STATUS_GOOD. + * Otherwise, this means that the scanner isn't ready to use. + */ +static void +print_xml_s(xmlNode *node, SANE_Status *status) +{ + int x = 0; + + while (node) { + if (node->type == XML_ELEMENT_NODE) { + if (find_nodes_s(node)) { + if (strcmp((const char *)node->name, "State") == 0) + x = 1; + } + if (x == 1 && strcmp((const char *)xmlNodeGetContent(node), "Idle") == 0) + *status = SANE_STATUS_GOOD; + } + print_xml_s(node->children, status); + node = node->next; + } +} + +/** + * \fn SANE_Status escl_status(SANE_String_Const name) + * \brief Function that finally recovers the scanner status ('Idle', or not), using curl. + * This function is called in the 'sane_open' function and it's the equivalent of + * the following curl command : "curl http(s)://'ip':'port'/eSCL/ScannerStatus". + * + * \return status (if everything is OK, status = SANE_STATUS_GOOD, otherwise, SANE_STATUS_NO_MEM/SANE_STATUS_INVAL) + */ +SANE_Status +escl_status(SANE_String_Const name) +{ + SANE_Status status; + CURL *curl_handle = NULL; + struct idle *var = NULL; + xmlDoc *data = NULL; + xmlNode *node = NULL; + const char *scanner_status = "/eSCL/ScannerStatus"; + char tmp[PATH_MAX] = { 0 }; + + if (name == NULL) + return (SANE_STATUS_NO_MEM); + var = (struct idle*)calloc(1, sizeof(struct idle)); + if (var == NULL) + return (SANE_STATUS_NO_MEM); + var->memory = malloc(1); + var->size = 0; + curl_handle = curl_easy_init(); + strcpy(tmp, name); + strcat(tmp, scanner_status); + curl_easy_setopt(curl_handle, CURLOPT_URL, tmp); + DBG( 1, "Get Status : %s.\n", tmp); + if (strncmp(name, "https", 5) == 0) { + DBG( 1, "Ignoring safety certificates, use https\n"); + curl_easy_setopt(curl_handle, CURLOPT_SSL_VERIFYPEER, 0L); + curl_easy_setopt(curl_handle, CURLOPT_SSL_VERIFYHOST, 0L); + } + curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, memory_callback_s); + curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)var); + if (curl_easy_perform(curl_handle) != CURLE_OK) { + DBG( 1, "The scanner didn't respond.\n"); + status = SANE_STATUS_INVAL; + goto clean_data; + } + data = xmlReadMemory(var->memory, var->size, "file.xml", NULL, 0); + if (data == NULL) { + status = SANE_STATUS_NO_MEM; + goto clean_data; + } + node = xmlDocGetRootElement(data); + if (node == NULL) { + status = SANE_STATUS_NO_MEM; + goto clean; + } + status = SANE_STATUS_DEVICE_BUSY; + print_xml_s(node, &status); +clean: + xmlFreeDoc(data); +clean_data: + xmlCleanupParser(); + xmlMemoryDump(); + curl_easy_cleanup(curl_handle); + free(var->memory); + free(var); + return (status); +} |