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| #include<stdlib.h>
#include<stdio.h>
#include<unistd.h>
#include<string.h>
#include<unistd.h>
#include <sys/prctl.h>
#include <linux/filter.h>
#include <linux/seccomp.h>
#include "user.pb-c.h"
char buffer[1024];
char *chunk_list[5];
int add_count = 4;
int show_count = 2;
void *ptr;
void welcome()
{
puts("welcome to user management system");
puts("Here, you can manage some users");
}
void setbox()
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD+BPF_W+BPF_ABS,4),
BPF_JUMP(BPF_JMP+BPF_JEQ,0xc000003e,0,2),
BPF_STMT(BPF_LD+BPF_W+BPF_ABS,0),
BPF_JUMP(BPF_JMP+BPF_JEQ,59,0,1),
BPF_STMT(BPF_RET+BPF_K,SECCOMP_RET_KILL),
BPF_STMT(BPF_RET+BPF_K,SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
.filter = filter,
};
prctl(PR_SET_NO_NEW_PRIVS,1,0,0,0);
prctl(PR_SET_SECCOMP,SECCOMP_MODE_FILTER,&prog);
}
void menu() {
puts("1. add a user");
puts("2. edit a user");
puts("3. show a user");
puts("4. delete a user");
puts("your choice: ");
}
void add(const char *username,size_t username_len,const char *description,size_t description_len)
{
char name[0x40];
char desc[0x80];
if(add_count > 0)
{
int index;
for(index = 0;index < 5;index++)
{
if(!chunk_list[index]) break;
}
if(index < 5)
{
chunk_list[index] = malloc(0xc0);
if(username_len > 0x40 || description_len > 0x80)
puts("too long!");
else
{ memcpy(name, username,username_len);
memcpy(chunk_list[index], name, username_len + 8);
memcpy(desc, description,description_len);
memcpy(chunk_list[index] + 64, desc, description_len + 8);
}
}
else
{
puts("what?");
}
}
else
{
puts("you have no choice!");
}
add_count--;
}
void edit(uint64_t msg_id,const char *username,size_t username_len,const char *description,size_t description_len)
{
if(chunk_list[msg_id])
{
if(username_len > 0x40 || description_len > 0x80)
puts("too long!");
else
{
memcpy(chunk_list[msg_id], username, username_len);
memcpy(chunk_list[msg_id] + 64, description, description_len);
}
}
else
{
puts("what?");
}
}
void delete(uint64_t msg_id) {
ptr = chunk_list[msg_id];
if(ptr)
{
free(ptr);
ptr = 0LL;
puts("delete success!");
}
else
{
puts("what?");
}
}
void show(uint64_t msg_id) {
if(show_count > 0)
{
if(chunk_list[msg_id])
{
printf("the content: %s\n",chunk_list[msg_id]);
printf("the content: %s\n",chunk_list[msg_id] + 64);
}
else
{
puts("nothing happen");
}
}
else
{
puts("you have no choice!");
}
show_count--;
}
void real_main(uint64_t action_id, uint64_t msg_id, const char *username_bytes, size_t username_len, const char *description_bytes, size_t description_len)
{
if(action_id == 1)
add(username_bytes,username_len,description_bytes,description_len);
else if(action_id == 2)
edit(msg_id,username_bytes,username_len,description_bytes,description_len);
else if(action_id == 3)
show(msg_id);
else if(action_id == 4)
delete(msg_id);
else
puts("invalid choice.");
}
int main() {
setvbuf(stdin, 0LL, 2, 0LL);
setvbuf(stdout, 0LL, 2, 0LL);
setvbuf(stderr, 0LL, 2, 0LL);
setbox();
welcome();
User user_msg = USER__INIT;
while (1)
{
menu();
memset(buffer, 0, sizeof(buffer));
ssize_t len = read(0, buffer, sizeof(buffer));
void *msg = user__unpack(NULL, len, buffer);
if (!msg) {
break;
}
memcpy(&user_msg, msg, sizeof(User));
real_main(user_msg.action_id, user_msg.msg_id, user_msg.username.data, user_msg.username.len, user_msg.description.data, user_msg.description.len);
}
return 0;
}
|
