date: add rudimentary support for setting date/time

apps/date.c

@@ -15,6 +15,7 @@
  * Copyright (C) 2018 K. Lange
  */
 #include <stdio.h>
+#include <string.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/time.h>
@@ -32,6 +33,45 @@ static void show_usage(int argc, char * argv[]) {
 			"\n", argv[0], argv[0]);
 }
 
+int digits(const char * s, int len) {
+	for (int i = 0; i < len; ++i) {
+		if (s[i] < '0' || s[i] > '9') return 0;
+	}
+	return 1;
+}
+
+int mmddhhmm(struct tm * tm, const char * str) {
+	int month = (str[0]-'0') * 10 + (str[1]-'0');
+	int day   = (str[2]-'0') * 10 + (str[3]-'0');
+	int hour  = (str[4]-'0') * 10 + (str[5]-'0');
+	int min   = (str[6]-'0') * 10 + (str[7]-'0');
+
+	if (month < 1 || month > 12) return 0;
+	if (day < 1 || day > 31) return 0;
+	if (hour < 0 || hour > 23) return 0;
+	if (min < 0 || min > 59) return 0;
+
+	tm->tm_mon = month - 1;
+	tm->tm_mday = day;
+	tm->tm_hour = hour;
+	tm->tm_min = min;
+
+	return 1;
+}
+
+int ddyy(struct tm * tm, const char * str) {
+	int year = (str[0]-'0') * 1000 + (str[1]-'0') * 100 + (str[2]-'0') * 10 + (str[3]-'0');
+	tm->tm_year = year - 1900;
+	return 1;
+}
+
+int secs(struct tm * tm, const char * str) {
+	int sec = (str[0]-'0') * 10 + (str[1]-'0');
+	if (sec < 0 || sec > 59) return 0;
+	tm->tm_sec = sec;
+	return 1;
+}
+
 int main(int argc, char * argv[]) {
 	char * format = "%a %d %b %Y %T %Z";
 	struct tm * timeinfo;
@@ -47,12 +87,47 @@ int main(int argc, char * argv[]) {
 		}
 	}
 
+	gettimeofday(&now, NULL);
+	timeinfo = localtime((time_t *)&now.tv_sec);
+
 	if (optind < argc && *argv[optind] == '+') {
 		format = &argv[optind][1];
-	}
+	} else if (optind < argc) {
 
-	gettimeofday(&now, NULL); //time(NULL);
-	timeinfo = localtime((time_t *)&now.tv_sec);
+		int len =strlen(argv[optind]);
+
+		if (len == 8) {
+			if (!digits(argv[optind], 8)) goto _invalid;
+			if (!mmddhhmm(timeinfo, argv[optind])) goto _invalid;
+			goto set_time;
+		} else if (len == 11) {
+			if (argv[optind][8] != '.') goto _invalid;
+			if (!digits(argv[optind], 8) || !digits(argv[optind]+9,2)) goto _invalid;
+			if (!mmddhhmm(timeinfo, argv[optind])) goto _invalid;
+			if (!secs(timeinfo, argv[optind]+9)) goto _invalid;
+			goto set_time;
+		} else if (len == 12) {
+			if (!digits(argv[optind], 12)) goto _invalid;
+			if (!mmddhhmm(timeinfo, argv[optind])) goto _invalid;
+			if (!ddyy(timeinfo, argv[optind]+8)) goto _invalid;
+			goto set_time;
+		} else if (len == 15) {
+			if (argv[optind][12] != '.') goto _invalid;
+			if (!digits(argv[optind], 12) || !digits(argv[optind]+13,2)) goto _invalid;
+			if (!mmddhhmm(timeinfo, argv[optind])) goto _invalid;
+			if (!ddyy(timeinfo, argv[optind]+8)) goto _invalid;
+			if (!secs(timeinfo, argv[optind]+13)) goto _invalid;
+			goto set_time;
+		}
+_invalid:
+		fprintf(stderr, "date: only 'MMDDhhmm', 'MMDDhhmm.ss', 'MMDDhhmmCCYY' and 'MMDDhhmmCCYY.ss' are supported for setting time.\n");
+		return 1;
+
+set_time:
+		now.tv_usec = 0;
+		now.tv_sec = mktime(timeinfo);
+		return settimeofday(&now, NULL);
+	}
 
 	strftime(buf,BUFSIZ,format,timeinfo);
 	puts(buf);

base/usr/include/sys/time.h

@@ -16,5 +16,6 @@ struct timezone {
 };
 
 extern int gettimeofday(struct timeval *p, void *z);
+extern int settimeofday(struct timeval *p, void *z);
 
 _End_C_Header

base/usr/include/syscall.h

@@ -221,6 +221,7 @@ DECL_SYSCALL2(getgroups, int, int*);
 DECL_SYSCALL2(setgroups, int, const int*);
 DECL_SYSCALL1(times, struct tms*);
 DECL_SYSCALL4(ptrace, int, int, void*, void*);
+DECL_SYSCALL2(settimeofday, void *, void *);
 
 _End_C_Header
 

base/usr/include/syscall_nums.h

@@ -72,3 +72,4 @@
 #define SYS_GETGROUPS 69
 #define SYS_SETGROUPS 70
 #define SYS_TIMES 71
+#define SYS_SETTIMEOFDAY 72

kernel/arch/aarch64/main.c

@@ -24,6 +24,7 @@
 #include <kernel/misc.h>
 #include <kernel/ptrace.h>
 #include <kernel/ksym.h>
+#include <errno.h>
 
 #include <sys/ptrace.h>
 
@@ -122,6 +123,20 @@ uint64_t now(void) {
 	return t.tv_sec;
 }
 
+static spin_lock_t _time_set_lock;
+
+int settimeofday(struct timeval * t, void *z) {
+	if (!t) return -EINVAL;
+	if (t->tv_sec < 0 || t->tv_usec < 0 || t->tv_usec > 1000000) return -EINVAL;
+
+	spin_lock(_time_set_lock);
+	uint64_t clock_time = now();
+	arch_boot_time += t->tv_sec - clock_time;
+	spin_unlock(_time_set_lock);
+
+	return 0;
+}
+
 void relative_time(unsigned long seconds, unsigned long subseconds, unsigned long * out_seconds, unsigned long * out_subseconds) {
 	if (!arch_boot_time) {
 		*out_seconds = 0;

kernel/arch/x86_64/cmos.c

@@ -13,6 +13,7 @@
  * of the NCSA / University of Illinois License - see LICENSE.md
  * Copyright (C) 2021 K. Lange
  */
+#include <errno.h>
 #include <kernel/printf.h>
 #include <kernel/string.h>
 #include <kernel/process.h>
@@ -324,6 +325,27 @@ uint64_t now(void) {
 	return t.tv_sec;
 }
 
+static spin_lock_t _time_set_lock;
+
+/**
+ * Set the system clock time
+ *
+ * TODO: A lot of this time stuff needs to be made more generic,
+ *       it's shared pretty directly with aarch64...
+ */
+int settimeofday(struct timeval * t, void *z) {
+	if (!t) return -EINVAL;
+	if (t->tv_sec < 0 || t->tv_usec < 0 || t->tv_usec > 1000000) return -EINVAL;
+
+	spin_lock(_time_set_lock);
+	uint64_t clock_time = now();
+	arch_boot_time += t->tv_sec - clock_time;
+	spin_unlock(_time_set_lock);
+
+	return 0;
+}
+
+
 /**
  * @brief Calculate a time in the future.
  *

kernel/sys/syscall.c

@@ -557,6 +557,14 @@ long sys_gettimeofday(struct timeval * tv, void * tz) {
 	return gettimeofday(tv, tz);
 }
 
+long sys_settimeofday(struct timeval * tv, void * tz) {
+	extern int settimeofday(struct timeval * t, void *z);
+	if (this_core->current_process->user != USER_ROOT_UID) return -EPERM;
+	PTR_VALIDATE(tv);
+	PTR_VALIDATE(tz);
+	return settimeofday(tv,tz);
+}
+
 long sys_getuid(void) {
 	return (long)this_core->current_process->real_user;
 }
@@ -1146,6 +1154,7 @@ static long (*syscalls[])() = {
 	[SYS_SETGROUPS]    = sys_setgroups,
 	[SYS_TIMES]        = sys_times,
 	[SYS_PTRACE]       = ptrace_handle,
+	[SYS_SETTIMEOFDAY] = sys_settimeofday,
 
 	[SYS_SOCKET]       = net_socket,
 	[SYS_SETSOCKOPT]   = net_setsockopt,

libc/time/settimeofday.c

@@ -0,0 +1,11 @@
+#include <sys/time.h>
+#include <syscall.h>
+#include <syscall_nums.h>
+
+DEFN_SYSCALL2(settimeofday, SYS_SETTIMEOFDAY, void *, void *);
+
+int settimeofday(struct timeval *p, void *z){
+	return syscall_settimeofday(p,z);
+}
+
+