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mirror of https://github.com/falk-werner/webfuse-provider synced 2024-10-27 20:44:10 +00:00
falk-werner_webfuse-provider/examples/provider/main.c
2020-06-16 23:57:41 +02:00

383 lines
9.0 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
#include "webfuse_provider/webfuse_provider.h"
struct config
{
char * url;
struct wfp_client_config * client_config;
bool show_help;
};
enum fs_entry_type
{
FS_FILE,
FS_DIR
};
struct fs_entry
{
ino_t parent;
ino_t inode;
char const * name;
int mode;
enum fs_entry_type type;
size_t content_length;
char const * content;
};
struct fs
{
struct fs_entry const * entries;
};
static void show_help()
{
printf(
"webfuse-provider, Copyright (c) 2019, webfuse authors <https://github.com/falk-werner/webfuse>\n"
"Example for websocket file system provider\n"
"\n"
"Usage: webfuse-provider -u <url> [-k <key_path>] [-c <cert_path>]\n"
"\n"
"Options:\n"
"\t-u, --url URL of webfuse server (required)\n"
"\t-k, --key_path Path to private key of provider (default: not set, TLS disabled)\n"
"\t-c, --cert_path Path to certificate of provider (defautl: not set, TLS disabled)\n"
"\t-h, --help prints this message\n"
"\n"
"Example:\n"
"\twebfuse-provider -u ws://localhost:8080/\n"
"\n"
);
}
static int parse_arguments(
int argc,
char* argv[],
struct config * config)
{
static struct option const options[] =
{
{"url", required_argument, NULL, 'u'},
{"key_path", required_argument, NULL, 'k'},
{"cert_path", required_argument, NULL, 'c'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, NULL, 0}
};
int result = EXIT_SUCCESS;
bool finished = false;
while (!finished)
{
int option_index = 0;
int const c = getopt_long(argc, argv, "u:k:c:h", options, &option_index);
switch (c)
{
case -1:
finished = true;
break;
case 'h':
config->show_help = true;
finished = true;
break;
case 'u':
free(config->url);
config->url = strdup(optarg);
break;
case 'k':
wfp_client_config_set_keypath(config->client_config, optarg);
break;
case 'c':
wfp_client_config_set_certpath(config->client_config, optarg);
break;
default:
fprintf(stderr, "error: unknown argument\n");
finished = true;
result = EXIT_FAILURE;
break;
}
if (NULL == config->url)
{
fprintf(stderr, "error: missing required argument \"-u\"\n");
result = EXIT_FAILURE;
}
if (result != EXIT_SUCCESS)
{
config->show_help = true;
}
}
return result;
}
static struct fs_entry const * fs_getentry(
struct fs * fs,
ino_t inode)
{
for (size_t i = 0; 0 != fs->entries[i].inode; i++)
{
struct fs_entry const * entry = &fs->entries[i];
if (inode == entry->inode)
{
return entry;
}
}
return NULL;
}
static struct fs_entry const * fs_getentry_byname(
struct fs * fs,
ino_t parent,
char const * name)
{
for( size_t i = 0; 0 != fs->entries[i].inode; i++)
{
struct fs_entry const * entry = &fs->entries[i];
if ((parent == entry->parent) && (0 == strcmp(name, entry->name)))
{
return entry;
}
}
return NULL;
}
static void fs_stat(
struct fs_entry const * entry,
struct stat * stat)
{
memset(stat, 0, sizeof(struct stat));
stat->st_ino = entry->inode;
stat->st_mode = entry->mode;
if (FS_DIR == entry->type)
{
stat->st_mode |= S_IFDIR;
}
if (FS_FILE == entry->type)
{
stat->st_mode |= S_IFREG;
stat->st_size = entry->content_length;
}
}
static void fs_lookup(
struct wfp_request * request,
ino_t parent,
char const * name,
void * user_data)
{
struct fs * fs = (struct fs*) user_data;
struct fs_entry const * entry = fs_getentry_byname(fs, parent, name);
if (NULL != entry)
{
struct stat stat;
fs_stat(entry, &stat);
wfp_respond_lookup(request, &stat);
}
else
{
wfp_respond_error(request, WFP_BAD_NOENTRY);
}
}
static void fs_getattr(
struct wfp_request * request,
ino_t inode,
void * user_data)
{
struct fs * fs = (struct fs*) user_data;
struct fs_entry const * entry = fs_getentry(fs, inode);
if (NULL != entry)
{
struct stat stat;
fs_stat(entry, &stat);
wfp_respond_getattr(request, &stat);
}
else
{
wfp_respond_error(request, WFP_BAD_NOENTRY);
}
}
static void fs_readdir(
struct wfp_request * request,
ino_t directory,
void * user_data)
{
struct fs * fs = (struct fs*) user_data;
struct fs_entry const * dir = fs_getentry(fs, directory);
if ((NULL != dir) && (FS_DIR == dir->type))
{
struct wfp_dirbuffer * buffer = wfp_dirbuffer_create();
wfp_dirbuffer_add(buffer, ".", dir->inode);
wfp_dirbuffer_add(buffer, "..", dir->inode);
for(size_t i = 0; 0 != fs->entries[i].inode; i++)
{
struct fs_entry const * entry = &fs->entries[i];
if (directory == entry->parent)
{
wfp_dirbuffer_add(buffer, entry->name, entry->inode);
}
}
wfp_respond_readdir(request, buffer);
wfp_dirbuffer_dispose(buffer);
}
else
{
wfp_respond_error(request, WFP_BAD_NOENTRY);
}
}
static void fs_open(
struct wfp_request * request,
ino_t inode,
int flags,
void * user_data)
{
struct fs * fs = (struct fs*) user_data;
struct fs_entry const * entry = fs_getentry(fs, inode);
if ((NULL != entry) && (FS_FILE == entry->type))
{
if (O_RDONLY == (flags & O_ACCMODE))
{
wfp_respond_open(request, 0U);
}
else
{
wfp_respond_error(request, WFP_BAD_ACCESS_DENIED);
}
}
else
{
wfp_respond_error(request, WFP_BAD_NOENTRY);
}
}
static size_t min(size_t const a, size_t const b)
{
return (a < b) ? a : b;
}
static void fs_read(
struct wfp_request * request,
ino_t inode,
uint32_t handle,
size_t offset,
size_t length,
void * user_data)
{
(void) handle;
struct fs * fs = (struct fs*) user_data;
struct fs_entry const * entry = fs_getentry(fs, inode);
if ((NULL != entry) && (FS_FILE == entry->type))
{
if (entry->content_length > offset)
{
size_t const remaining = entry->content_length - offset;
size_t const count = min(remaining, length);
wfp_respond_read(request, &entry->content[offset], count);
}
else
{
wfp_respond_error(request, WFP_BAD);
}
}
else
{
wfp_respond_error(request, WFP_BAD_NOENTRY);
}
}
static volatile bool shutdown_requested = false;
static void on_interrupt(int signal_id)
{
(void) signal_id;
shutdown_requested = true;
}
int main(int argc, char* argv[])
{
struct config config;
config.url = NULL;
config.show_help = false;
config.client_config = wfp_client_config_create();
int result = parse_arguments(argc, argv, &config);
if (EXIT_SUCCESS == result)
{
static struct fs_entry const entries[]=
{
{.parent = 0, .inode = 1, .name = "<root>", .mode = 0555, .type = FS_DIR},
{
.parent = 1,
.inode = 2,
.name = "hello.txt",
.mode = 0444,
.type = FS_FILE,
.content="hello, world!",
.content_length = 13,
},
{.parent = 0, .inode = 0, .name = NULL}
};
struct fs fs =
{
.entries = entries
};
signal(SIGINT, &on_interrupt);
wfp_client_config_set_userdata(config.client_config, &fs);
wfp_client_config_set_onlookup(config.client_config, &fs_lookup);
wfp_client_config_set_ongetattr(config.client_config, &fs_getattr);
wfp_client_config_set_onreaddir(config.client_config, &fs_readdir);
wfp_client_config_set_onopen(config.client_config, &fs_open);
wfp_client_config_set_onread(config.client_config, &fs_read);
struct wfp_client * client = wfp_client_create(config.client_config);
wfp_client_connect(client, config.url);
while (!shutdown_requested)
{
wfp_client_service(client);
}
wfp_client_dispose(client);
}
if (config.show_help)
{
show_help();
}
free(config.url);
wfp_client_config_dispose(config.client_config);
return result;
}