Add some system calls, plus a fakish /bin/login

kernel/include/process.h

@@ -15,6 +15,8 @@ typedef unsigned int  user_t;
 typedef unsigned int  group_t;
 typedef unsigned char status_t;
 
+#define USER_ROOT_UID (user_t)0
+
 /* Unix waitpid() options */
 enum wait_option{
 	WCONTINUED,

kernel/include/syscall.h

@@ -84,6 +84,9 @@ DECL_SYSCALL0(getgraphicswidth);
 DECL_SYSCALL0(getgraphicsheight);
 DECL_SYSCALL0(getgraphicsdepth);
 
+DECL_SYSCALL0(getuid);
+DECL_SYSCALL1(setuid, unsigned int);
+
 
 #endif
 /*

kernel/sys/syscall.c

@@ -9,6 +9,7 @@
 #include <logging.h>
 #include <fs.h>
 #include <pipe.h>
+#include <version.h>
 
 #define SPECIAL_CASE_STDIO
 
@@ -232,6 +233,34 @@ static int dup2(int old, int new) {
 	return new;
 }
 
+static int getuid() {
+	return current_process->user;
+}
+
+static int setuid(user_t new_uid) {
+	if (current_process->user != USER_ROOT_UID) {
+		current_process->user = new_uid;
+		return 0;
+	}
+	return -1;
+}
+
+static int kernel_name_XXX(char * buffer) {
+	char version_number[1024];
+	sprintf(version_number, __kernel_version_format,
+			__kernel_version_major,
+			__kernel_version_minor,
+			__kernel_version_lower,
+			__kernel_version_suffix);
+	return sprintf(buffer, "%s %s %s %s %s %s",
+			__kernel_name,
+			version_number,
+			__kernel_version_codename,
+			__kernel_build_date,
+			__kernel_build_time,
+			__kernel_arch);
+}
+
 /*
  * System Call Internals
  */
@@ -261,6 +290,9 @@ static uintptr_t syscalls[] = {
 	(uintptr_t)&getgraphicsdepth,	/* 20 */
 	(uintptr_t)&mkpipe,
 	(uintptr_t)&dup2,
+	(uintptr_t)&getuid,
+	(uintptr_t)&setuid,				/* 24 */
+	(uintptr_t)&kernel_name_XXX,
 	0
 };
 uint32_t num_syscalls;

loader/syscall.c

@@ -17,3 +17,6 @@ DEFN_SYSCALL1(wait, 17, int)
 DEFN_SYSCALL0(getgraphicswidth,  18)
 DEFN_SYSCALL0(getgraphicsheight, 19)
 DEFN_SYSCALL0(getgraphicsdepth,  20)
+
+DEFN_SYSCALL0(getuid, 23)
+DEFN_SYSCALL1(setuid, 24, unsigned int)

userspace/esh.c

@@ -68,6 +68,20 @@ int main(int argc, char ** argv) {
 	int  nowait = 0;
 	int  free_cmd = 0;
 	int  last_ret = 0;
+
+	FILE * motd = fopen("/etc/motd", "r");
+	if (motd) {
+		size_t s = 0;
+		fseek(motd, 0, SEEK_END);
+		s = ftell(motd);
+		fseek(motd, 0, SEEK_SET);
+		char * m = malloc(sizeof(char) * s);
+		fread(m, s, 1, motd);
+		fwrite(m, s, 1, stdout);
+		fprintf(stdout, "\n");
+		fflush(stdout);
+	}
+
 	while (1) {
 		char * cmd = malloc(sizeof(char) * 1024);
 

userspace/login.c

@@ -0,0 +1,117 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ *
+ * Login Service
+ *
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+DEFN_SYSCALL1(wait, 17, unsigned int);
+DEFN_SYSCALL1(setuid, 24, unsigned int);
+DEFN_SYSCALL1(kernel_string_XXX, 25, char *);
+
+typedef struct {
+	int uid;
+	char * name;
+	char * pass;
+} user_combo;
+
+user_combo users[] = {
+	{0, "root", "toor"},
+	{1, "klange", "herp"}
+};
+
+int n_users = 2;
+
+int readline(char * buf, size_t size, uint8_t display) {
+	size_t collected = 0;
+	while (collected < size - 1) {
+		char * cmd = malloc(2);
+		size_t nread = fread(cmd, 1, 1, stdin);
+		if (nread > 0) {
+			if (cmd[0] < 10 || (cmd[0] > 10 && cmd[0] < 32) || cmd[0] > 126) {
+				continue;
+			}
+			buf[collected] = cmd[0];
+			if (display || buf[collected] == '\n') {
+				printf("%c", cmd[0]);
+			}
+			fflush(stdout);
+			if (buf[collected] == '\n') {
+				goto _done;
+			}
+			collected++;
+		}
+	}
+_done:
+	buf[collected] = '\0';
+	return collected;
+}
+
+int checkUserPass(char * user, char * pass) {
+	for (int i = 0; i < n_users; ++i) {
+		if (!strcmp(user, users[0].name)) {
+			if (!strcmp(pass, users[0].pass)) {
+				return users[0].uid;
+			}
+		}
+	}
+	return -1;
+}
+
+int main(int argc, char ** argv) {
+	/* TODO: Read /etc/shadow */
+
+	/* TODO: uname() */
+	char * _uname = malloc(sizeof(char) * 1024);
+	syscall_kernel_string_XXX(_uname);
+
+	fprintf(stdout, "\n%s\n\n", _uname);
+
+	while (1) {
+		char * username = malloc(sizeof(char) * 1024);
+		char * password = malloc(sizeof(char) * 1024);
+
+		/* TODO: gethostname() */
+		char * _hostname = "test";
+
+		fprintf(stdout, "%s login: ", _hostname);
+		fflush(stdout);
+		readline(username, 1024, 1);
+
+		fprintf(stdout, "password: ");
+		fflush(stdout);
+		readline(password, 1024, 0);
+
+		int uid = checkUserPass(username, password);
+
+		if (uid < 0) {
+			fprintf(stdout, "\nLogin failed.\n");
+			continue;
+		}
+
+		pid_t pid = getpid();
+
+		uint32_t f = fork();
+		if (getpid() != pid) {
+			char * args[] = {
+				"/bin/esh",
+				NULL
+			};
+			syscall_setuid(uid);
+			int i = execve(args[0], args, NULL);
+		} else {
+			syscall_wait(f);
+		}
+		free(username);
+		free(password);
+	}
+
+	return 0;
+}

userspace/terminal.c

@@ -2853,8 +2853,8 @@ int main(int argc, char ** argv) {
 		//syscall_dup2(ifd, 0);
 		syscall_dup2(ofd, 1);
 		syscall_dup2(ofd, 2);
-		char * tokens[] = {"/bin/esh",NULL};
-		int i = execve("/bin/esh", tokens, NULL);
+		char * tokens[] = {"/bin/login",NULL};
+		int i = execve(tokens[0], tokens, NULL);
 		return 0;
 	} else {
 		char buf[1024];