Upgrade libutils to C++

native/jni/utils/misc.cpp

@@ -0,0 +1,195 @@
+/* misc.cpp - Store all functions that are unable to be catagorized clearly
+ */
+ 
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <unistd.h>
+#include <syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/sysmacros.h>
+
+#include "logging.h"
+#include "utils.h"
+
+unsigned get_shell_uid() {
+	struct passwd* ppwd = getpwnam("shell");
+	if (nullptr == ppwd)
+		return 2000;
+
+	return ppwd->pw_uid;
+}
+
+unsigned get_system_uid() {
+	struct passwd* ppwd = getpwnam("system");
+	if (nullptr == ppwd)
+		return 1000;
+
+	return ppwd->pw_uid;
+}
+
+unsigned get_radio_uid() {
+	struct passwd* ppwd = getpwnam("radio");
+	if (nullptr == ppwd)
+		return 1001;
+
+	return ppwd->pw_uid;
+}
+
+/* Check if the string only contains digits */
+int is_num(const char *s) {
+	int len = strlen(s);
+	for (int i = 0; i < len; ++i)
+		if (s[i] < '0' || s[i] > '9')
+			return 0;
+	return 1;
+}
+
+/* Read a whole line from file descriptor */
+ssize_t fdgets(char *buf, const size_t size, int fd) {
+	ssize_t len = 0;
+	buf[0] = '\0';
+	while (len < size - 1) {
+		int ret = read(fd, buf + len, 1);
+		if (ret < 0)
+			return -1;
+		if (ret == 0)
+			break;
+		if (buf[len] == '\0' || buf[len++] == '\n') {
+			buf[len] = '\0';
+			break;
+		}
+	}
+	buf[size - 1] = '\0';
+	return len;
+}
+
+int switch_mnt_ns(int pid) {
+	char mnt[32];
+	snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);
+	if(access(mnt, R_OK) == -1) return 1; // Maybe process died..
+
+	int fd, ret;
+	fd = xopen(mnt, O_RDONLY);
+	if (fd < 0) return 1;
+	// Switch to its namespace
+	ret = xsetns(fd, 0);
+	close(fd);
+	return ret;
+}
+
+int fork_dont_care() {
+	int pid = xfork();
+	if (pid) {
+		waitpid(pid, nullptr, 0);
+		return pid;
+	} else if ((pid = xfork())) {
+		exit(0);
+	}
+	return 0;
+}
+
+void gen_rand_str(char *buf, int len) {
+	const char base[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+	int urandom;
+	if (access("/dev/urandom", R_OK) == 0) {
+		urandom = xopen("/dev/urandom", O_RDONLY | O_CLOEXEC);
+	} else {
+		mknod("/urandom", S_IFCHR | 0666, makedev(1, 9));
+		urandom = xopen("/urandom", O_RDONLY | O_CLOEXEC);
+		unlink("/urandom");
+	}
+	xxread(urandom, buf, len - 1);
+	close(urandom);
+	for (int i = 0; i < len - 1; ++i) {
+		buf[i] = base[buf[i] % (sizeof(base) - 1)];
+	}
+	buf[len - 1] = '\0';
+}
+
+int strend(const char *s1, const char *s2) {
+	size_t l1 = strlen(s1);
+	size_t l2 = strlen(s2);
+	return strcmp(s1 + l1 - l2, s2);
+}
+
+/* Original source: https://opensource.apple.com/source/cvs/cvs-19/cvs/lib/getline.c
+ * License: GPL 2 or later
+ * Adjusted to match POSIX */
+#define MIN_CHUNK 64
+ssize_t __getdelim(char **lineptr, size_t *n, int delim, FILE *stream) {
+	size_t nchars_avail;
+	char *read_pos;
+
+	if (!lineptr || !n || !stream) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (!*lineptr) {
+		*n = MIN_CHUNK;
+		*lineptr = (char *) malloc(*n);
+		if (!*lineptr) {
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	nchars_avail = *n;
+	read_pos = *lineptr;
+
+	while (1) {
+		int save_errno;
+		int c = getc(stream);
+
+		save_errno = errno;
+
+		if (nchars_avail < 2) {
+			if (*n > MIN_CHUNK)
+				*n *= 2;
+			else
+				*n += MIN_CHUNK;
+
+			nchars_avail = *n + *lineptr - read_pos;
+			*lineptr = (char *) realloc(*lineptr, *n);
+			if (!*lineptr) {
+				errno = ENOMEM;
+				return -1;
+			}
+			read_pos = *n - nchars_avail + *lineptr;
+		}
+
+		if (ferror(stream)) {
+			errno = save_errno;
+			return -1;
+		}
+
+		if (c == EOF) {
+			if (read_pos == *lineptr)
+				return -1;
+			else
+				break;
+		}
+
+		*read_pos++ = c;
+		nchars_avail--;
+
+		if (c == delim)
+			break;
+	}
+
+	*read_pos = '\0';
+
+	return read_pos - *lineptr;
+}
+
+ssize_t __getline(char **lineptr, size_t *n, FILE *stream) {
+	return __getdelim(lineptr, n, '\n', stream);
+}
+
+int __fsetxattr(int fd, const char *name, const void *value, size_t size, int flags) {
+	return (int) syscall(__NR_fsetxattr, fd, name, value, size, flags);
+}