feat: 支持pid容器内访问进程挂载目录

Close #I6DCM8

Signed-off-by: zhushengle <zhushengle@huawei.com>
Change-Id: Ie1002ca48f9a73429e767136c1f11b1a8b137b48

syscall/fs_syscall.c

@@ -291,17 +291,135 @@ ssize_t SysWrite(int fd, const void *buf, size_t nbytes)
     return ret;
 }
 
+// int vfs_normalize_path(const char *directory, const char *filename, char **pathname)
+#ifdef LOSCFG_PID_CONTAINER
+#ifdef LOSCFG_PROC_PROCESS_DIR
+#define PROCESS_DIR_ROOT   "/proc"
+static char *NextName(char *pos, uint8_t *len)
+{
+    char *name = NULL;
+    while (*pos != 0 && *pos == '/') {
+        pos++;
+    }
+    if (*pos == '\0') {
+        return NULL;
+    }
+    name = (char *)pos;
+    while (*pos != '\0' && *pos != '/') {
+        pos++;
+    }
+    *len = pos - name;
+    return name;
+}
+
+static unsigned int ProcRealProcessIDGet(unsigned int pid)
+{
+    unsigned int intSave;
+    if (OS_PID_CHECK_INVALID(pid)) {
+        return 0;
+    }
+
+    SCHEDULER_LOCK(intSave);
+    LosProcessCB *pcb = OsGetPCBFromVpid(pid);
+    if (pcb == NULL) {
+        SCHEDULER_UNLOCK(intSave);
+        return 0;
+    }
+
+    int rootPid = OsGetRootPid(pcb);
+    SCHEDULER_UNLOCK(intSave);
+    if ((rootPid == OS_INVALID_VALUE) || (rootPid == pid)) {
+        return 0;
+    }
+
+    return rootPid;
+}
+
+static int ProcRealProcessDirGet(char *path)
+{
+    char pidBuf[PATH_MAX] = {0};
+    char *fullPath = NULL;
+    uint8_t strLen = 0;
+    int pid, rootPid;
+    int ret = vfs_normalize_path(NULL, path, &fullPath);
+    if (ret < 0) {
+        return ret;
+    }
+
+    int procLen = strlen(PROCESS_DIR_ROOT);
+    if (strncmp(fullPath, PROCESS_DIR_ROOT, procLen) != 0) {
+        free(fullPath);
+        return 0;
+    }
+
+    char *pidStr = NextName(fullPath + procLen, &strLen);
+    if (pidStr == NULL) {
+        free(fullPath);
+        return 0;
+    }
+
+    if ((*pidStr <= '0') || (*pidStr > '9')) {
+        free(fullPath);
+        return 0;
+    }
+
+    if (memcpy_s(pidBuf, PATH_MAX, pidStr, strLen) != EOK) {
+        free(fullPath);
+        return 0;
+    }
+    pidBuf[strLen] = '\0';
+
+    pid = atoi(pidBuf);
+    if (pid == 0) {
+        free(fullPath);
+        return 0;
+    }
+
+    rootPid = ProcRealProcessIDGet((unsigned)pid);
+    if (rootPid == 0) {
+        free(fullPath);
+        return 0;
+    }
+
+    if (snprintf_s(path, PATH_MAX + 1, PATH_MAX, "/proc/%d%s", rootPid, (pidStr + strLen)) < 0) {
+        free(fullPath);
+        return -EFAULT;
+    }
+
+    free(fullPath);
+    return 0;
+}
+#endif
+#endif
+
+static int GetPath(const char *path, char **pathRet)
+{
+    int ret = UserPathCopy(path, pathRet);
+    if (ret != 0) {
+        return ret;
+    }
+#ifdef LOSCFG_PID_CONTAINER
+#ifdef LOSCFG_PROC_PROCESS_DIR
+    ret = ProcRealProcessDirGet(*pathRet);
+    if (ret != 0) {
+        return ret;
+    }
+#endif
+#endif
+    return 0;
+}
+
 int SysOpen(const char *path, int oflags, ...)
 {
     int ret;
-    int procFd;
+    int procFd = -1;
     mode_t mode = DEFAULT_FILE_MODE; /* 0666: File read-write properties. */
     char *pathRet = NULL;
 
     if (path != NULL) {
-        ret = UserPathCopy(path, &pathRet);
+        ret = GetPath(path, &pathRet);
         if (ret != 0) {
-            return ret;
+            goto ERROUT;
         }
     }
 
@@ -432,6 +550,15 @@ ssize_t SysReadlink(const char *pathname, char *buf, size_t bufsize)
         if (ret != 0) {
             goto OUT;
         }
+
+#ifdef LOSCFG_PID_CONTAINER
+#ifdef LOSCFG_PROC_PROCESS_DIR
+        ret = ProcRealProcessDirGet(pathRet);
+        if (ret != 0) {
+            goto OUT;
+        }
+#endif
+#endif
     }
 
     if (!LOS_IsUserAddressRange((vaddr_t)(UINTPTR)buf, bufsize)) {
@@ -1840,6 +1967,15 @@ ssize_t SysReadlinkat(int dirfd, const char *pathname, char *buf, size_t bufsize
         if (ret != 0) {
             goto OUT;
         }
+
+#ifdef LOSCFG_PID_CONTAINER
+#ifdef LOSCFG_PROC_PROCESS_DIR
+        ret = ProcRealProcessDirGet(pathRet);
+        if (ret != 0) {
+            goto OUT;
+        }
+#endif
+#endif
     }
 
     if (dirfd != AT_FDCWD) {

testsuites/unittest/container/full/It_pid_container_002.cpp

@@ -110,25 +110,26 @@ static int ChildFunClone1(void *p)
     int ret;
     pid_t pid = getpid();
     int childFunRet = (int)pid;
-    void *pstk = malloc(STACK_SIZE);
-    if (pstk == NULL) {
-        return EXIT_CODE_ERRNO_2;
-    }
-    int childPid = clone(ChildFunClone2, (char *)pstk + STACK_SIZE, CLONE_NEWPID | SIGCHLD, NULL);
+    char *containerType = "pid";
+    int childPid = clone(ChildFunClone2, NULL, CLONE_NEWPID | SIGCHLD, NULL);
     if (childPid == -1) {
-        free(pstk);
         return EXIT_CODE_ERRNO_3;
     }
 
+    auto linkBuffer = ReadlinkContainer(childPid, containerType);
+    auto linkBuffer1 = ReadlinkContainer(getpid(), containerType);
+    ret = linkBuffer.compare(linkBuffer1);
+    if (ret == 0) {
+        (void)waitpid(childPid, &status, 0);
+        return EXIT_CODE_ERRNO_5;
+    }
+
     ret = waitpid(childPid, &status, 0);
     ret = WIFEXITED(status);
     ret = WEXITSTATUS(status);
     if (ret != CONTAINER_FIRST_PID) {
-        free(pstk);
         return EXIT_CODE_ERRNO_4;
     }
-
-    free(pstk);
     return childFunRet;
 }