From d01ee55602127e0278c0d67e0e310a5a623dff94 Mon Sep 17 00:00:00 2001 From: p6a8nelzg <1973393745@qq.com> Date: Sun, 26 Jun 2022 20:30:35 +0800 Subject: [PATCH] =?UTF-8?q?ADD=20file=20via=20upload=20execve2=E6=9C=AA?= =?UTF-8?q?=E5=AE=9E=E7=8E=B0=20getcwd=E5=AE=9E=E7=8E=B0=E5=B7=AE=E4=B8=80?= =?UTF-8?q?=E7=82=B9?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- 1.c | 401 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 401 insertions(+) create mode 100644 1.c diff --git a/1.c b/1.c new file mode 100644 index 0000000..db89bad --- /dev/null +++ b/1.c @@ -0,0 +1,401 @@ +/* + * linux/kernel/sys.c + * + * (C) 1991 Linus Torvalds + */ + +#include + +#include //调度程序头文件。定义了任务结构task_struct,任务0的数据, + //还有一些有关描述符参数设置和获取的嵌入式汇编函数宏语言 +#include +#include //内核头文件 +#include +#include +#include //系统名称结构头文件 + +#include +int sys_ftime() +{ + return -ENOSYS; +} + +int sys_break() +{ + return -ENOSYS; +} + +int sys_ptrace() +{ + return -ENOSYS; +} + +int sys_stty() +{ + return -ENOSYS; +} + +int sys_gtty() +{ + return -ENOSYS; +} + +int sys_rename() +{ + return -ENOSYS; +} + +int sys_prof() +{ + return -ENOSYS; +} + +int sys_setregid(int rgid, int egid) +{ + if (rgid>0) { + if ((current->gid == rgid) || + suser()) + current->gid = rgid; + else + return(-EPERM); + } + if (egid>0) { + if ((current->gid == egid) || + (current->egid == egid) || + suser()) { + current->egid = egid; + current->sgid = egid; + } else + return(-EPERM); + } + return 0; +} +//设置进程组号 +int sys_setgid(int gid) +{ +/* return(sys_setregid(gid, gid)); */ + if (suser()) + current->gid = current->egid = current->sgid = gid; + else if ((gid == current->gid) || (gid == current->sgid)) + current->egid = gid; + else + return -EPERM; + return 0; +} + +int sys_acct() +{ + return -ENOSYS; +} + +int sys_phys() +{ + return -ENOSYS; +} + +int sys_lock() +{ + return -ENOSYS; +} + +int sys_mpx() +{ + return -ENOSYS; +} + +int sys_ulimit() +{ + return -ENOSYS; +} +//返回从1970年1月1号 开始记时的时间值(s) +int sys_time(long * tloc) +{ + int i; + + i = CURRENT_TIME; + if (tloc) { + verify_area(tloc,4); + put_fs_long(i,(unsigned long *)tloc); //把时间值存储到用户空间 + //段寄存器fs被默认地指向用户数据空间，因此此函数可利用fs段寄存器来访问用户空间中的值 + } + return i; +} + +/* + * Unprivileged users may change the real user id to the effective uid + * or vice versa. + */ +int sys_setreuid(int ruid, int euid) +{ + int old_ruid = current->uid; + + if (ruid>0) { + if ((current->euid==ruid) || + (old_ruid == ruid) || + suser()) + current->uid = ruid; + else + return(-EPERM); + } + if (euid>0) { + if ((old_ruid == euid) || + (current->euid == euid) || + suser()) { + current->euid = euid; + current->suid = euid; + } else { + current->uid = old_ruid; + return(-EPERM); + } + } + return 0; +} + +int sys_setuid(int uid) +{ +/* return(sys_setreuid(uid, uid)); */ + if (suser()) + current->uid = current->euid = current->suid = uid; + else if ((uid == current->uid) || (uid == current->suid)) + current->euid = uid; + else + return -EPERM; + return(0); +} + +int sys_stime(long * tptr) +{ + if (!suser()) + return -EPERM; + startup_time = get_fs_long((unsigned long *)tptr) - jiffies/HZ; + return 0; +} +//获取当前任务运行时间统计值 +int sys_times(struct tms * tbuf) +{ + if (tbuf) { + verify_area(tbuf,sizeof *tbuf); + put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime); + put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime); + put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime); + put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime); + } + return jiffies; +} +//设置程序在内存中的末端位置 +int sys_brk(unsigned long end_data_seg) +{ + //如果参数值大于代码结尾，并且小于（堆栈-16kb），则设置新数据段结尾值 + if (end_data_seg >= current->end_code && + end_data_seg < current->start_stack - 16384) + current->brk = end_data_seg; + return current->brk; +} + +/* + * This needs some heave checking ... + * I just haven't get the stomach for it. I also don't fully + * understand sessions/pgrp etc. Let somebody who does explain it. + */ +int sys_setpgid(int pid, int pgid) +{ + int i; + + if (!pid) + pid = current->pid; + if (!pgid) + pgid = current->pid; + for (i=0 ; ipid==pid) { + if (task[i]->leader) + return -EPERM; + if (task[i]->session != current->session) + return -EPERM; + task[i]->pgrp = pgid; + return 0; + } + return -ESRCH; +} + +int sys_getpgrp(void) +{ + return current->pgrp; +} + +int sys_setsid(void) +{ + if (current->leader && !suser()) + return -EPERM; + current->leader = 1; + current->session = current->pgrp = current->pid; + current->tty = -1; + return current->pgrp; +} + +int sys_getgroups() +{ + return -ENOSYS; +} + +int sys_setgroups() +{ + return -ENOSYS; +} + +int sys_uname(struct utsname * name) +{ + static struct utsname thisname = { + "linux .0","nodename","release ","version ","machine " + }; + int i; + + if (!name) return -ERROR; + verify_area(name,sizeof *name); + for(i=0;iumask; + + current->umask = mask & 0777; + return (old); +} + +int sys_pipe2(void){ + return 0; +} + +int sys_sleep(unsigned int seconds){ + sys_signal(SIGALRM,SIG_IGN); + sys_alarm(seconds); + sys_pause(); + return 0; +} + +int sys_execve2(){ + return 0; +} +/*获取目录的目录项*/ +/*fd指目录描述符，dirp指目录信息，count指目录信息大小*/ +int sys_getdents(unsigned int fd,struct linux_dirent *dirp,unsigned int count) +{ + struct file *file; + struct m_inode *inode; + struct buffer_head *bh; + struct dir_entry *de; + struct linux_dirent *temp; + char * buf; + int i,len = 0,ret = 0; + + if(!count)return -1; + if(fd>=NR_OPEN)return -1; /*fd超过进程最多打开文件数20*/ + + file=current->filp[fd]; + if(!file)return -1; + inode = file->f_inode; + temp = (struct linux_dirent *)malloc(sizeof(struct linux_dirent)); //目录信息 + buf = (char*)malloc(sizeof(struct linux_dirent)); + bh = bread(inode->i_dev , inode->i_zone[0]); //读取指向的数据块 + + for (;reti_size;ret += sizeof(struct dir_entry)){ + if (len >= count-sizeof(struct linux_dirent)) + break; /* full */ + de = (struct dir_entry *)(bh->b_data + ret);/*de更新为当前目录项*/ + if (!de->inode )/*如果节点号为空，就退出*/ + continue; + /*用temp保存当前目录项信息*/ + temp->d_ino = de->inode; + temp->d_off = 0; + temp->d_reclen = sizeof(struct linux_dirent); + strcpy(temp->d_name,de->name); + /*将数据写回到用户*/ + memcpy(buf, temp, sizeof(struct linux_dirent)); + for (i=0;i < sizeof(struct linux_dirent);i++){ + put_fs_byte(*(buf+i), ((char*)dirp)+len+i); //用来访问用户程序的数据 + } + len += sizeof(struct linux_dirent); + } + return len; +} +//参考find_entry +int sys_getcwd(char* buf,size_t size){ + struct buffer_head *bh; + struct dir_entry*de,*p_de; + + unsigned current_depth = 0; + struct m_inode* current_ino; + struct m_inode* parent_ino; + char* t_buf; + int ret = 0; + t_buf = (char*)malloc(256); + strcpy(t_buf,""); + buf = malloc(size); + if(!buf)return -1; + + for(;;){ + current_ino = namei("."); + parent_ino = namei(".."); + if(current_ino == parent_ino) //找到了根节点 + break; + sys_chdir(".."); + //read_inode(current_ino); 这是个静态函数 + //buf[current_depth++] = read_inode(current_ino);//根据节点号，在当前目录查找文件read_inode + bh = bread(parent_ino->i_dev,parent_ino->i_zone[0]); + for(;reti_size;ret+=sizeof(struct dir_entry)) + { + de = (struct dir_entry*)(bh->b_data + ret); + if(!de->inode)break; + if(de->inode == (current_ino->i_num)){ + memcpy(t_buf,de->name,NAME_LEN); + current_depth += NAME_LEN; + break; + } + } + //current_depth++; + } + // int i = current_depth-1; + // for(i;i >= 0;i--){ + // printk("/%s",buf[i]); + // } + // printk("%s\n",current_depth==0?"/":""); + // //复制过来 + int i; + for(i = 0;t_buf[i];i++){ + put_fs_byte(t_buf[i],buf+i); + } + return (int)buf; +}