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#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <errno.h>
#include "nfcommander.h"
#include "command.h"
#include "config.h"
#define COMMAND_ALIVE 1
#define COMMAND_STOPPED 2
#define INPUT_BUFFER_MAX 4096
typedef struct {
uint8_t flags;
pid_t child;
int iopipe[2];
nfc_tag_info_t* tag;
} command_t;
static size_t ncommands = 0;
static command_t* commands = NULL;
int command_handle(int fd){
size_t n = 0;
ssize_t bytes;
uint8_t input_buffer[INPUT_BUFFER_MAX];
//find matching command
for(n = 0; n < ncommands; n++){
if(commands[n].flags & COMMAND_ALIVE
&& fd == commands[n].iopipe[0]){
bytes = read(fd, input_buffer, sizeof(input_buffer));
if(bytes < 0){
perror("command/recv");
}
else if(bytes == 0){
printf("Command %lu pipe closed\n", n);
core_manage_fd(commands[n].iopipe[0], 0, system_command);
close(commands[n].iopipe[0]);
commands[n].iopipe[0] = -1;
}
else{
printf("%d bytes from command %lu\n", bytes, n);
}
return 0;
}
}
printf("Unhandled command fd\n");
return 1;
}
void command_reap(){
//TODO
printf("Reaping children\n");
}
static int command_spawn(command_t* cmd, char* command_name, char* command_static, size_t arg_length){
char* workdir = config_get("command", "chdir");
char* handler = config_get("command", "handler");
printf("Starting command %s, static %s\n", command_name, command_static);
if(pipe(cmd->iopipe)){
perror("cmd/pipe");
return 1;
}
cmd->child = fork();
switch(cmd->child){
case -1:
perror("cmd/fork");
return 1;
case 0:
//child
if(workdir && chdir(workdir)){
perror("child/chdir");
_exit(1);
}
//connect stdout
while((dup2(cmd->iopipe[1], STDOUT_FILENO) == -1) && (errno == EINTR)) {
}
close(cmd->iopipe[1]);
close(cmd->iopipe[0]);
execl(command_name, command_static, NULL);
perror("cmd/exec");
_exit(1);
default:
//parent
cmd->flags |= COMMAND_ALIVE;
close(cmd->iopipe[1]);
core_manage_fd(cmd->iopipe[0], 1, system_command);
}
return 0;
}
int command_start(nfc_tag_info_t* info){
size_t n = 0, p = ncommands, arg_length = 0;
uint8_t* command_name = NULL, *command_static = NULL;
for(n = 0; n < ncommands; n++){
//if command already in list, do nothing
if(commands[n].tag == info){
//this should not normally happen
return 0;
}
//mark available slot
if(!commands[n].tag && !commands[n].flags){
p = n;
}
}
//cant run without an actual command
if(!info->static_data || !info->static_length){
printf("Tag contains no command data\n");
return 0;
}
//parse out command data
command_name = calloc(info->static_length + 1, sizeof(uint8_t));
if(!command_name){
printf("Failed to allocate memory\n");
return 1;
}
memcpy(command_name, info->static_data, info->static_length);
for(n = 0; n < info->static_length; n++){
if(!isalnum(command_name[n])){
command_name[n] = 0;
if(info->static_length - n > 1){
command_static = command_name + n + 1;
arg_length = info->static_length - n - 1;
}
break;
}
}
//FIXME might want to parse out any non-graphs
if(p == ncommands){
commands = realloc(commands, (p + 1) * sizeof(command_t));
if(!commands){
ncommands = 0;
printf("Failed to allocate memory\n");
goto bail;
}
memset(commands + p, 0, sizeof(command_t));
ncommands++;
}
commands[p].tag = info;
if(command_spawn(commands + p, (char*) command_name, (char*) command_static, arg_length)){
//TODO clean up and free command instance
}
bail:
free(command_name);
return 0;
}
int command_stop(nfc_tag_info_t* info){
size_t n = 0;
for(n = 0; n < ncommands; n++){
if(commands[n].tag == info){
commands[n].tag = NULL;
if(commands[n].flags & COMMAND_ALIVE){
//TODO stop running command
commands[n].flags |= COMMAND_STOPPED;
}
}
}
return 0;
}
void command_free(){
size_t n = 0;
printf("Shutting down any remaining commands\n");
for(n = 0; n < ncommands; n++){
if(commands[n].flags & COMMAND_ALIVE){
//TODO stop command, terminate command
}
//TODO free allocated data
}
ncommands = 0;
free(commands);
commands = NULL;
}
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