#include <unistd.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <sys/mman.h>
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#include <sys/syscall.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <linux/memfd.h>
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#include <stdlib.h>
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#include <time.h>
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#include <stdarg.h>
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#include "memfd.h"
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#include <assert.h>
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#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
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} while (0)
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#define LOGFILE "/opt/vasystem/valog/memfd.log"
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/*****************************************************************************
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函 数 名 : mydebug
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功能描述 : 日志记录函数，记录到文件
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输入参数 : const char *fmt
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...
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输出参数 : 无
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返 回 值 : 无
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调用函数 :
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被调函数 :
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修改历史 :
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1.日 期 : 2018年1月15日
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作 者 : cheliequan
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修改内容 : 新生成函数
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*****************************************************************************/
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void mydebug(const char *fmt, ...)
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{
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char debugbuff[2048];
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int outlen;
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FILE *fp;
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va_list ap;
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time_t nowtime = time(NULL);
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struct tm *pNowtime=NULL;
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pNowtime = localtime(&nowtime);
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fp=fopen(LOGFILE,"a+");
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if(fp==NULL)
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{
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return;
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}
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va_start(ap, fmt);
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outlen=vsprintf(debugbuff,fmt,ap);
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va_end(ap);
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*(debugbuff+outlen) = 0;
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fprintf(fp,"%d-%02d-%02d %02d:%02d:%02d====",pNowtime->tm_year+1900,pNowtime->tm_mon+1,pNowtime->tm_mday,pNowtime->tm_hour,pNowtime->tm_min,pNowtime->tm_sec);
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fprintf(fp,"%s",debugbuff);
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fclose(fp);
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}
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static int sys_memfd_create(const char *name,
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unsigned int flags)
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{
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return syscall(__NR_memfd_create, name, flags);
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}
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int basic_shm_create(char *name, ssize_t len)
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{
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int fd;
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struct stat st;
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/* Create an anonymous file in tmpfs; */
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if(0 >= len)
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{
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return -1;
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}
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fd = sys_memfd_create(name, MFD_CLOEXEC);
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if (fd == -1)
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{
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errExit("memfd_create");
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}
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/* Size the file as specified on the command line */
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mydebug("length: %zu\n", len);
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if (ftruncate(fd, len) == -1)
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{
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errExit("ftruncate");
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}
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if (fstat (fd, &st))
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{
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errExit ("fstat");
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}
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mydebug("PID: %ld; fd: %d; /proc/%ld/fd/%d, atime: %lu.%lu\n",
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(long) getpid(), fd, (long) getpid(), fd, st.st_atim.tv_sec, st.st_atim.tv_nsec);
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return fd;
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}
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int basic_shm_path_open(int memfd, pid_t pid)
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{
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ssize_t len;
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int fd;
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struct stat st;
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if ((pid != 0) && (memfd != 0))
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{
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char fd_path[512] = {0};
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snprintf(fd_path, sizeof(fd_path), "/proc/%d/fd/%d", pid, memfd);
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fd = open(fd_path, O_RDWR|O_CLOEXEC);
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if (fd == -1)
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{
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errExit("open");
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}
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}
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if (fstat (fd, &st))
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{
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errExit ("fstat");
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}
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len = st.st_size;
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mydebug("length: %zu, atime: %lu.%lu\n", len, st.st_atim.tv_sec, st.st_atim.tv_nsec);
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return fd;
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}
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int basic_shm_open(int fd, pid_t pid, int flags)
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{
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int memfd = -1;
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switch(flags){
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case local_open_flag:
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memfd = basic_shm_path_open(fd, getpid());
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break;
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case remote_open_flag:
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memfd = basic_shm_path_open(fd, pid);
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break;
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default:
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mydebug("not support\n");
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break;
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}
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return memfd;
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}
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int basic_shm_mmap(int fd, unsigned char** ppaddr)
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{
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struct stat st;
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ssize_t len;
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if (fstat (fd, &st))
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{
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errExit ("fstat");
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}
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len = st.st_size;
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*ppaddr = (unsigned char*) mmap (NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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if (*ppaddr == MAP_FAILED)
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{
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errExit("mmap");
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}
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mydebug("length: %zu, atime: %lu.%lu\n", len, st.st_atim.tv_sec, st.st_atim.tv_nsec);
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return len;
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}
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int basic_shm_unmmap(int fd, unsigned char** ppaddr)
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{
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struct stat st;
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ssize_t len;
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int ret = 0;
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if (fstat (fd, &st))
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{
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errExit ("fstat");
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}
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len = st.st_size;
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ret = munmap((void *)*ppaddr, len);
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if (ret == -1)
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{
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errExit("munmap()");
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}
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*ppaddr = NULL;
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mydebug("length: %zu, atime: %lu.%lu\n", len, st.st_atim.tv_sec, st.st_atim.tv_nsec);
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return len;
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}
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int basic_shm_close(int fd)
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{
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int ret = -1;
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if (fd >= 0)
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{
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ret = close(fd);
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}
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return ret;
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}
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static void mfd_assert_size(int fd, size_t size)
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{
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struct stat st;
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int r;
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r = fstat(fd, &st);
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if (r < 0) {
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mydebug("fstat(%d) failed: %m\n", fd);
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} else if (st.st_size != size) {
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mydebug("wrong file size %lld, but expected %lld\n",
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(long long)st.st_size, (long long)size);
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}
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}
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static int mfd_assert_open(int fd, int flags, mode_t mode)
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{
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char buf[512];
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int r;
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sprintf(buf, "/proc/self/fd/%d", fd);
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r = open(buf, flags, mode);
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if (r < 0)
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{
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mydebug("open(%s) failed: %m\n", buf);
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}
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return r;
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}
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int basic_shm_shrink(int fd, ssize_t len)
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{
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int r, fd2;
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r = ftruncate(fd, len);
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if (r < 0) {
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mydebug("ftruncate(SHRINK) failed\n");
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return r;
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}
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mfd_assert_size(fd, len);
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fd2 = mfd_assert_open(fd,
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O_RDWR | O_CREAT | O_TRUNC,
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S_IRUSR | S_IWUSR);
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if (fd2 < 0) {
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mydebug("basic_shm_shrink failed\n");
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return fd2;
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}
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return fd2;
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}
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int basic_shm_grow(int fd, ssize_t len)
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{
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int r;
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r = ftruncate(fd, len);
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if (r < 0) {
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mydebug("ftruncate(GROW) failed: %m\n");
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return r;
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}
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mfd_assert_size(fd, len);
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return r;
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}
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