HW1: 加入使用者身份相關內容

7 files changed, 378 insertions, 4 deletions

diff --git a/hw1/Makefile.am b/hw1/Makefile.am
index b314c9b..a35e644 100644
--- a/hw1/Makefile.am
+++ b/hw1/Makefile.am
@@ -1,7 +1,25 @@
+NULL =
+
 EXTRA_DIST = autogen.sh
+
 bin_PROGRAMS = ras-server
 noinst_LIBRARIES = libbasic.a libras.a
-libbasic_a_SOURCES = xwrap.c xwrap.h basic-list.c basic-list.h
-libras_a_SOURCES = socktool.c socktool.h connection.c connection.h
-ras_server_SOURCES = server-main.c server.c server.h session.c session.h
+
+libbasic_a_SOURCES = \
+	xwrap.c xwrap.h \
+	basic-list.c basic-list.h \
+	basic-array.c basic-arrstr.c basic-array2.c basic-array.h \
+	$(NULL)
+
+libras_a_SOURCES = \
+	socktool.c socktool.h \
+	connection.c connection.h \
+	$(NULL)
+
+ras_server_SOURCES = \
+	server.c server.h \
+	session.c session.h \
+	server-main.c \
+	$(NULL)
+
 ras_server_LDADD = $(top_builddir)/libbasic.a $(top_builddir)/libras.a
diff --git a/hw1/basic-array.c b/hw1/basic-array.c
new file mode 100644
index 0000000..5d5f61e
--- /dev/null
+++ b/hw1/basic-array.c
@@ -0,0 +1,133 @@
+#include "xwrap.h"
+#include <stdlib.h>
+#include <string.h>
+#include "basic-array.h"
+
+Array* array_create_setmax(int itemsize, int len, int maxlen){
+	if(itemsize <= 0 || len < 0 || maxlen < len){
+		return NULL;
+	}
+	Array* arr = (Array*)xmalloc(sizeof(Array));
+	if(arr == NULL){
+		return NULL;
+	}
+	arr->arr_itemsize = itemsize;
+	arr->arr_curlen = len;
+	arr->arr_maxlen = maxlen;
+	if(maxlen != 0){
+		arr->arr_data = xmalloc(itemsize * maxlen);
+		if(arr->arr_data == NULL){
+			free(arr);
+			return NULL;
+		}
+	}else{
+		arr->arr_data = NULL;
+	}
+	return arr;
+}
+
+Array* array_create(int itemsize, int len){
+	return array_create_setmax(itemsize, len, len);
+}
+
+void array_free(Array* arr){
+	if(arr->arr_data != NULL){
+		free(arr->arr_data);
+	}
+	free(arr);
+}
+
+int array_pushback(Array* arr, const void* data){
+	if((arr->arr_maxlen) < (arr->arr_curlen + 1)){
+		if(arr->arr_maxlen != 0){
+			if(array_setmax(arr, arr->arr_maxlen*2) < 0){
+				return -1;
+			}
+		}else{
+			if(array_setmax(arr, 1) < 0){
+				return -1;
+			}
+		}
+	}
+	memcpy(array_vp(arr, arr->arr_curlen), data, arr->arr_itemsize);
+	arr->arr_curlen++;
+	return 0;
+}
+
+int array_setlen(Array* arr, int len){
+	if(len > (arr->arr_maxlen)){
+		if(array_setmax(arr, len) < 0){
+			return -1;
+		}else{
+			arr->arr_curlen = len;
+		}
+	}else{
+		arr->arr_curlen = len;
+		return 0;
+	}
+	return 0;
+}
+
+int array_setmax(Array* arr, int max){
+	void* newptr;
+	if(arr->arr_data == NULL){
+		newptr = xmalloc((arr->arr_itemsize)*max);
+		if(newptr == NULL){
+			return -1;
+		}else{
+			arr->arr_maxlen = max;
+			arr->arr_data = newptr;
+			return 0;
+		}
+	}
+	newptr = realloc(arr->arr_data, (arr->arr_itemsize)*max);
+	if(newptr == NULL){
+		return -1;
+	}else{
+		arr->arr_maxlen = max;
+		arr->arr_data = newptr;
+	}
+	return 0;
+}
+
+int array_strip(Array* arr){
+	if(arr->arr_data == NULL){
+		return 0;
+	}
+	Array* newptr; 
+	/* 其實縮小空間營該一定會成功才對......
+	 * 不過還是保險一點，加個判斷式，別說 memory leak 是我害的
+	 * 當然也是避免編譯器一直跳 warning
+	 */
+	if((arr->arr_maxlen) > (arr->arr_curlen)){
+		arr->arr_maxlen = arr->arr_curlen;
+		newptr = realloc(arr->arr_data, (arr->arr_curlen)*(arr->arr_itemsize));
+		if(newptr == NULL){
+			return -1;
+		}
+		arr->arr_data = newptr;
+	}
+	return 0;
+}
+
+/* 基本上直接玩 struct 的函式還是少用吧 */
+void* array_drop_struct(Array* arr){
+	void* toreturn = arr->arr_data;
+	free(arr);
+	return toreturn;
+}
+
+Array* array_make_struct(void* data, int itemsize, int len, int maxlen){
+	if(itemsize <= 0 || len < 0 || maxlen < len){
+		return NULL;
+	}
+	Array* arr = (Array*)xmalloc(sizeof(Array));
+	if(arr == NULL){
+		return NULL;
+	}
+	arr->arr_itemsize = itemsize;
+	arr->arr_curlen = len;
+	arr->arr_maxlen = maxlen;
+	arr->arr_data = data;
+	return arr;
+}
diff --git a/hw1/basic-array.h b/hw1/basic-array.h
new file mode 100644
index 0000000..ee0de42
--- /dev/null
+++ b/hw1/basic-array.h
@@ -0,0 +1,65 @@
+#include "xwrap.h"
+#ifndef L4LIB_DYNAMIC_ARRAY
+#define L4LIB_DYNAMIC_ARRAY
+
+#include <stdio.h> /* 取得 FILE */
+
+/*********** 一維陣列 ***********/
+
+typedef struct l4lib_dyn_arr{
+	int arr_itemsize;		/* 每個項目的大小 */
+	int arr_curlen;			/* 陣列總長度 */
+	int arr_maxlen;			/* 陣列最大長度 */
+	void* arr_data;			/* 資料區 */
+} Array ;
+
+Array* array_create_setmax(int, int, int);
+Array* array_create(int, int);
+void array_free(Array*);
+int array_pushback(Array*, const void*);
+#define array_popback(arr) (((arr)->arr_curlen)--)
+#define array_getlen(arr) ((arr)->arr_curlen)
+int array_setlen(Array*, int);
+#define array_getmax(arr) ((arr)->arr_maxlen)
+int array_setmax(Array*, int);
+int array_strip(Array*);
+#define array_itemsize(arr) ((arr)->arr_itemsize)
+#define array_data(arr) ((arr)->arr_data)
+#define array_v(arr, type, num) \
+	(*(((type*)((arr)->arr_data))+(num)))
+#define array_vp(arr, num) \
+	((void*)(((char*)((arr)->arr_data))+(((arr)->arr_itemsize)*(num))))
+
+#define array_readline() (array_filereadline_delim(stdin, '\n'))
+#define array_readline_delim(delim) (array_filereadline_delim(stdin, (delim)))
+#define array_filereadline(infile) (array_filereadline_delim((infile), '\n'))
+Array* array_filereadline_delim(FILE*, int);
+
+Array* array_dup(const Array*);
+int array_combine(Array*, const Array*);
+
+void* array_drop_struct(Array*);
+Array* array_make_struct(void*, int, int, int);
+
+/*********** 二維陣列 (其實是用一維陣列來模擬，功能有限) ***********/
+
+typedef struct l4lib_dyn_2darr{
+	int arr_itemsize;		/* 每個項目的大小 */
+	int arr_lenx;	 	 	/* 陣列 x 方向長度 */
+	int arr_leny;  			/* 陣列 y 方向長度 */
+	void* arr_data; 	   	/* 資料區 */
+} ArrayTwo ;
+
+ArrayTwo* array_two_create(int, int, int);
+void array_two_free(ArrayTwo*);
+#define array_two_getlenx(arr) ((arr)->arr_lenx)
+#define array_two_getleny(arr) ((arr)->arr_leny)
+#define array_two_itemsize(arr) ((arr)->arr_itemsize)
+#define array_two_data(arr) ((arr)->arr_data)
+#define array_two_v(arr, type, numx, numy) \
+	(*(((type*)((arr)->arr_data))+((numx)*(array_two_getleny(arr)))+(numy)))
+#define array_two_vp(arr, numx, numy) \
+	((void*)(((char*)((arr)->arr_data))+ \
+	((arr)->arr_itemsize)*((numx)*(array_two_getleny(arr))+(numy))))
+
+#endif
diff --git a/hw1/basic-array2.c b/hw1/basic-array2.c
new file mode 100644
index 0000000..848ec67
--- /dev/null
+++ b/hw1/basic-array2.c
@@ -0,0 +1,27 @@
+#include "xwrap.h"
+#include <stdlib.h>
+#include "basic-array.h"
+
+ArrayTwo* array_two_create(int itemsize, int lenx, int leny){
+	if(lenx <= 0 || leny <= 0 || itemsize <= 0){
+		return NULL;
+	}
+	ArrayTwo* arr = (ArrayTwo*)xmalloc(sizeof(ArrayTwo));
+	if(arr == NULL){
+		return NULL;
+	}
+	arr->arr_itemsize = itemsize;
+	arr->arr_lenx = lenx;
+	arr->arr_leny = leny;
+	arr->arr_data = xmalloc(itemsize*lenx*leny);
+	if(arr->arr_data == NULL){
+		free(arr);
+		return NULL;
+	}
+	return arr;
+}
+
+void array_two_free(ArrayTwo* arr){
+	free(arr->arr_data);
+	free(arr);
+}
diff --git a/hw1/basic-arrstr.c b/hw1/basic-arrstr.c
new file mode 100644
index 0000000..f15bd22
--- /dev/null
+++ b/hw1/basic-arrstr.c
@@ -0,0 +1,48 @@
+#include "xwrap.h"
+#include <string.h>
+#include "basic-array.h"
+
+Array* array_dup(const Array* arr){
+	Array* newarr = array_create_setmax(
+			array_itemsize(arr), array_getlen(arr), array_getmax(arr));
+	if(newarr == NULL){
+		return NULL;
+	}
+	memcpy(newarr->arr_data, arr->arr_data, 
+			array_getlen(arr) * array_itemsize(arr));
+	return newarr;
+}
+
+int array_combine(Array* arr, const Array* att){
+	if(array_itemsize(arr) != array_itemsize(att)){
+		return -2;
+	}
+	if(array_setlen(arr, array_getlen(arr) + array_getlen(att)) < 0){
+		return -1;
+	}
+	memcpy(array_vp(arr, array_getlen(arr)), att->arr_data,
+			array_getlen(att) * array_itemsize(att));
+	return 0;
+}
+
+Array* array_filereadline_delim(FILE* infile, int chr){
+	Array* newarr = array_create(1, 0);
+	if(newarr == NULL){
+		return NULL;
+	}
+	int c;
+	char towrite;
+	while((c = getc(infile)) != chr && !feof(infile)){
+		towrite = c;
+		if(array_pushback(newarr, (void*)&towrite) < 0){
+			array_free(newarr);
+			return NULL;
+		}
+	}
+	towrite = '\0';
+	if(array_pushback(newarr, (void*)&towrite) < 0){
+		array_free(newarr);
+		return NULL;
+	}
+	return newarr;
+}
diff --git a/hw1/configure.ac b/hw1/configure.ac
index b85f2d5..e13206a 100644
--- a/hw1/configure.ac
+++ b/hw1/configure.ac
@@ -27,6 +27,7 @@ AC_TYPE_UINT16_T
 # Checks for library functions.
 AC_FUNC_MALLOC
 AC_FUNC_REALLOC
+AC_CHECK_FUNCS([setgroups initgroups])
 
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
diff --git a/hw1/session.c b/hw1/session.c
index dd416a8..40a0e65 100644
--- a/hw1/session.c
+++ b/hw1/session.c
@@ -8,6 +8,7 @@
 #include "socktool.h"
 #include "connection.h"
 #include "server.h"
+#include "basic-array.h"
 
 #include <errno.h>
 #include <grp.h>
@@ -92,7 +93,7 @@ int ras_session_read_header (RasSession* session) {
 		next = oneline + onelinelen;
 	} else {
 		*space = '\0';
-		for (space++; *space != '\0' && *space != ' '; space++);
+		for (space++; *space == '\0' && *space == ' '; space++);
 		next = space;
 	}
 
@@ -110,6 +111,87 @@ int ras_session_read_header (RasSession* session) {
 		return -1;
 	}
 
+	struct passwd* login_user = NULL;
+	if (*next != '\0') {
+		login_user = getpwnam (next);
+		if (login_user == NULL) {
+			const char baduser_msg[] = "Error: User not found.\n";
+			const int baduser_len = STATIC_STRLEN (baduser_msg);
+			ras_socktool_write_string (RAS_CONN (session)->fd, baduser_msg, baduser_len);
+			ras_session_log (session, "user %s cannot be found", next);
+			free (oneline);
+			return -1;
+		}
+	}
+
+	free (oneline);
+
+	if (RAS_CONN (session)->perm == RAS_CONN_PERM_RESTRICTED) {
+		uid_t real_uid = getuid ();
+		if (login_user != NULL && login_user->pw_uid != real_uid) {
+			const char rest_msg[] = "Error: You are not permitted to login from here.\n";
+			const int rest_len = STATIC_STRLEN (rest_msg);
+			ras_socktool_write_string (RAS_CONN (session)->fd, rest_msg, rest_len);
+			ras_session_log (session, "user %s is not permitted", login_user->pw_name);
+			return -1;
+		}
+		setuid (real_uid);
+	} else {
+		const char sufail_msg[] = "Error: Unable to change the user credential.\n";
+		const int sufail_len = STATIC_STRLEN (sufail_msg);
+		int rval;
+
+#if defined(HAVE_INITGROUPS)
+		rval = initgroups (login_user->pw_name, login_user->pw_gid);
+#elif defined(HAVE_SETGROUPS)
+		struct group* groupentry;
+		Array* grouplist = array_create (sizeof (gid_t), 1);
+		int errno_saved;
+
+		array_pushback (grouplist, &login_user->pw_gid);
+		setgrent ();
+		while ((groupentry = getgrent ()) != NULL) {
+			for (int i = 0; groupentry->gr_mem[i] != NULL; i++) {
+				if (strcmp (groupentry->gr_mem[i], login_user->pw_name) == 0) {
+					array_pushback (grouplist, &groupentry->gr_gid);
+				}
+			}
+		}
+		endgrent ();
+
+		rval = setgroups (array_getlen (grouplist), array_data (grouplist));
+
+		errno_saved = errno;
+		array_free (grouplist);
+		errno = errno_saved;
+#endif
+
+		if (rval < 0) {
+			write (RAS_CONN (session)->fd, sufail_msg, sufail_len);
+			ras_session_log (session,
+					"cannot set supplementary groups: %s", strerror (errno));
+			return -1;
+		}
+
+		rval = setgid (login_user->pw_gid);
+		if (rval < 0) {
+			write (RAS_CONN (session)->fd, sufail_msg, sufail_len);
+			ras_session_log (session,
+					"cannot set primary group to %d: %s",
+					login_user->pw_gid, strerror (errno));
+			return -1;
+		}
+
+		rval = setuid (login_user->pw_uid);
+		if (rval < 0) {
+			write (RAS_CONN (session)->fd, sufail_msg, sufail_len);
+			ras_session_log (session,
+					"cannot set user to %s (uid = %d): %s",
+					login_user->pw_name, login_user->pw_uid, strerror (errno));
+			return -1;
+		}
+	}
+
 
 	return 0;
 }