Attachment 2109 Details for Bug 1953 – Patch that implements xattr in sftp-server

[patch] Patch that implements xattr in sftp-server

openssh-5.9p1_xattr.patch (text/plain), 15.18 KB, created by e.kuemmerle on 2011-12-01 21:43:14 AEDT

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Creator: e.kuemmerle

Created: 2011-12-01 21:43:14 AEDT

Size: 15.18 KB

patch

obsolete

>diff -rupN openssh-5.9p1/sftp-server.c openssh-5.9p1_mod_xattr/sftp-server.c
>--- openssh-5.9p1/sftp-server.c	2011-06-20 06:42:52.000000000 +0200
>+++ openssh-5.9p1_mod_xattr/sftp-server.c	2011-11-30 15:34:38.121066184 +0100
>@@ -30,6 +30,11 @@
> #include <sys/statvfs.h>
> #endif
> 
>+#include <sys/xattr.h>
>+#ifndef ENOATTR
>+#define ENOATTR ENODATA
>+#endif
>+
> #include <dirent.h>
> #include <errno.h>
> #include <fcntl.h>
>@@ -51,6 +56,8 @@
> #include "sftp.h"
> #include "sftp-common.h"
> 
>+#define MAX_XATTR_DATA_LEN 100000
>+
> /* helper */
> #define get_int64()			buffer_get_int64(&iqueue);
> #define get_int()			buffer_get_int(&iqueue);
>@@ -73,6 +80,17 @@ u_int version;
> /* Disable writes */
> int readonly;
> 
>+/* xattr extension */
>+int xattr_caching;
>+
>+typedef struct Xattrib Xattrib;
>+
>+struct Xattrib {
>+	char *name;
>+	void *value;
>+	size_t size;
>+};
>+
> /* portable attributes, etc. */
> 
> typedef struct Stat Stat;
>@@ -81,6 +99,8 @@ struct Stat {
> 	char *name;
> 	char *long_name;
> 	Attrib attrib;
>+	Xattrib *xattrib;
>+	size_t xa_size;
> };
> 
> static int
>@@ -110,6 +130,22 @@ errno_to_portable(int unixerrno)
> 	case ENOSYS:
> 		ret = SSH2_FX_OP_UNSUPPORTED;
> 		break;
>+	case ENOATTR:
>+		ret = SSH2_FX_ENOATTR;
>+		break;
>+	case ENOSPC:
>+	case EDQUOT:
>+		ret = SSH2_FX_ENOSPC;
>+		break;
>+	case ENOTSUP:
>+		ret = SSH2_FX_ENOTSUP;
>+		break;
>+	case ERANGE:
>+		ret = SSH2_FX_ERANGE;
>+		break;
>+	case EMSGSIZE:
>+		ret = SSH2_FX_EMSGSIZE;
>+		break;
> 	default:
> 		ret = SSH2_FX_FAILURE;
> 		break;
>@@ -396,6 +432,11 @@ status_to_message(u_int32_t status)
> 		"No connection",		/* SSH_FX_NO_CONNECTION */
> 		"Connection lost",		/* SSH_FX_CONNECTION_LOST */
> 		"Operation unsupported",	/* SSH_FX_OP_UNSUPPORTED */
>+		"No such attribute",		/* SSH2_FX_ENOATTR */
>+		"No space",			/* SSH2_FX_ENOSPC */
>+		"Not supported",		/* SSH2_FX_ENOTSUP */
>+		"Range error",			/* SSH2_FX_ERANGE */
>+		"Message size error",		/* SSH2_FX_EMSGSIZE */
> 		"Unknown error"			/* Others */
> 	};
> 	return (status_messages[MIN(status,SSH2_FX_MAX)]);
>@@ -454,23 +495,65 @@ send_handle(u_int32_t id, int handle)
> }
> 
> static void
>+write_allxattr_data(Buffer *msg, Xattrib *xa, size_t xa_size) {
>+	buffer_put_int(msg, xa_size);
>+	if (xa_size == (size_t)-1)
>+		buffer_put_int(msg, *(int*)xa);
>+	else if (xa_size != 0) {
>+		size_t j;
>+		for (j=0; j<xa_size; ++j) {
>+			buffer_put_cstring(msg, xa[j].name);
>+			buffer_put_int(msg, xa[j].size);
>+			if (xa[j].size == (size_t)-1)
>+				buffer_put_int(msg, *(int*)xa[j].value);
>+			else if (xa[j].size != 0)
>+				buffer_append(msg, xa[j].value, xa[j].size);
>+		}
>+	}
>+}
>+
>+static void
>+send_names_start(Buffer *msg, u_int32_t id)
>+{
>+	debug("send_names_start %u", id);
>+	buffer_init(msg);
>+	buffer_put_char(msg, SSH2_FXP_NAME);
>+	buffer_put_int(msg, id);
>+	buffer_put_int(msg, 0);
>+}
>+
>+static void
>+send_names_next(Buffer *msg, u_int32_t id, const Stat *stats)
>+{
>+	buffer_put_cstring(msg, stats->name);
>+	buffer_put_cstring(msg, stats->long_name);
>+	encode_attrib(msg, &stats->attrib);
>+	if (xattr_caching)
>+		write_allxattr_data(msg, stats->xattrib, stats->xa_size);
>+}
>+
>+static void
>+send_names_end(Buffer *msg, int count)
>+{
>+	char buf[4];
>+	put_u32(buf, count);
>+	memcpy((char*)buffer_ptr(msg) + 5, buf, 4);
>+	send_msg(msg);
>+	buffer_free(msg);
>+}
>+
>+static void
> send_names(u_int32_t id, int count, const Stat *stats)
> {
> 	Buffer msg;
> 	int i;
> 
>-	buffer_init(&msg);
>-	buffer_put_char(&msg, SSH2_FXP_NAME);
>-	buffer_put_int(&msg, id);
>-	buffer_put_int(&msg, count);
>+	send_names_start(&msg, id);
> 	debug("request %u: sent names count %d", id, count);
> 	for (i = 0; i < count; i++) {
>-		buffer_put_cstring(&msg, stats[i].name);
>-		buffer_put_cstring(&msg, stats[i].long_name);
>-		encode_attrib(&msg, &stats[i].attrib);
>+		send_names_next(&msg, id, stats + i);
> 	}
>-	send_msg(&msg);
>-	buffer_free(&msg);
>+	send_names_end(&msg, count);
> }
> 
> static void
>@@ -538,6 +621,19 @@ process_init(void)
> 	/* hardlink extension */
> 	buffer_put_cstring(&msg, "hardlink@openssh.com");
> 	buffer_put_cstring(&msg, "1"); /* version */
>+	/* xattr extensions */
>+	buffer_put_cstring(&msg, "setxattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
>+	buffer_put_cstring(&msg, "getxattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
>+	buffer_put_cstring(&msg, "listxattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
>+	buffer_put_cstring(&msg, "removexattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
>+	buffer_put_cstring(&msg, "cachexattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
>+	buffer_put_cstring(&msg, "getallxattr@openssh.com");
>+	buffer_put_cstring(&msg, "1"); /* version */
> 	send_msg(&msg);
> 	buffer_free(&msg);
> }
>@@ -907,6 +1003,120 @@ process_opendir(void)
> 	xfree(path);
> }
> 
>+static void delete_xattr(Xattrib *xattr, size_t xa_size)
>+{
>+	if (xa_size != 0) {
>+		if (xa_size != (size_t)-1) {
>+			size_t i;
>+			for (i=0; i<xa_size; ++i) {
>+				xfree(xattr[i].name);
>+				if (xattr[i].size != 0) {
>+					xfree(xattr[i].value);
>+				}
>+			}
>+		}
>+		xfree(xattr);
>+	}
>+}
>+
>+static size_t get_xattr(const char *path, Xattrib **xattrib)
>+{
>+	size_t lsize = 1024;
>+	char *list = xmalloc(lsize);
>+	size_t lret;
>+	Xattrib *xattr = NULL;
>+	do {
>+		lret = llistxattr(path, list, lsize);
>+		if (lret == (size_t)-1) {
>+			if (errno == ERANGE) {
>+				lret = llistxattr(path, list, 0);
>+				if (lret != (size_t)-1) {
>+					if (lret > MAX_XATTR_DATA_LEN) {
>+						lret = (size_t)-1;
>+						errno = EMSGSIZE;
>+					}
>+					else {
>+						lsize = lret;
>+						list = xrealloc(list, lsize, 1);
>+						continue;
>+					}
>+				}
>+			}
>+		}
>+		break;
>+	} while (1);
>+	debug3("get_xattr: lret=%ld", lret);
>+
>+	if (lret == (size_t)-1) {
>+		xattr = xmalloc(sizeof(int));
>+		*(int*)xattr = errno_to_portable(errno);
>+	} else if (lret != 0) {
>+		char *p;
>+		char *list_end = list + lret;
>+		int cnt = 0;
>+		for (p=list; p<list_end; ++p)
>+			if (!*p)
>+				++cnt;
>+		debug3("get_xattr: cnt=%d", cnt);
>+		xattr = xcalloc(cnt, sizeof(Xattrib));
>+		size_t vsize = 1024;
>+		void *value = xmalloc(vsize);
>+		char *name = list;
>+		int i;
>+		size_t tot_siz = 0;
>+		for (i=0; i<cnt; ++i) {
>+			size_t nlen = strlen(name);
>+			size_t gret;
>+			do {
>+				gret = lgetxattr(path, name, value, vsize);
>+				//debug3("get_xattr: gret=%d, errno=%d(%d), name=%s, size=%ld, value=%s\n", gret, errno, ERANGE, name, vsize, value);
>+				if (gret == (size_t)-1) {
>+					if (errno == ERANGE) {
>+						gret = lgetxattr(path, name, value, 0);
>+						//debug3("get_xattr: gret=%d, errno=%d(%d), name=%s\n", gret, errno, ERANGE, name);
>+						if (gret != (size_t)-1) {
>+							if (gret > MAX_XATTR_DATA_LEN) {
>+								gret = (size_t)-1;
>+								errno = EMSGSIZE;
>+							}
>+							else {
>+								vsize = gret;
>+								value = xrealloc(value, vsize, 1);
>+								continue;
>+							}
>+						}
>+					}
>+				}
>+				break;
>+			} while (1);
>+			tot_siz += gret;
>+			if (tot_siz > MAX_XATTR_DATA_LEN)
>+				break;
>+			xattr[i].name = xstrdup(name);
>+			xattr[i].size = gret;
>+			if (gret == (size_t)-1) {
>+				xattr[i].value = xmalloc(sizeof(int));
>+				*(int*)xattr[i].value = errno_to_portable(errno);
>+			} else if (gret != 0) {
>+				xattr[i].value = xmalloc(gret);
>+				memcpy(xattr[i].value, value, gret);
>+			}
>+			//debug3("get_xattr: name=%s, size=%ld, value=%s\n", xattr[i].name, xattr[i].size, xattr[i].value);
>+			name += nlen+1;
>+		}
>+		if (i<cnt) {
>+			delete_xattr(xattr, i);
>+			xattr = xmalloc(sizeof(int));
>+			*(int*)xattr = errno_to_portable(EMSGSIZE);
>+		}
>+		xfree(value);
>+		lret = cnt;
>+	}
>+	xfree(list);
>+	*xattrib = xattr;
>+	return lret;
>+}
>+
> static void
> process_readdir(void)
> {
>@@ -927,39 +1137,42 @@ process_readdir(void)
> 	} else {
> 		struct stat st;
> 		char pathname[MAXPATHLEN];
>-		Stat *stats;
>-		int nstats = 10, count = 0, i;
>+		Stat stats;
>+		int count = 0;
>+		Buffer msg;
>+		int max_entrysize = 256 + MAXPATHLEN + 32 + 1024;
>+		debug3("readdir: xattr_caching=%d", xattr_caching);
>+		if (xattr_caching)
>+			max_entrysize += MAX_XATTR_DATA_LEN;
>+		send_names_start(&msg, id);
> 
>-		stats = xcalloc(nstats, sizeof(Stat));
> 		while ((dp = readdir(dirp)) != NULL) {
>-			if (count >= nstats) {
>-				nstats *= 2;
>-				stats = xrealloc(stats, nstats, sizeof(Stat));
>-			}
>-/* XXX OVERFLOW ? */
> 			snprintf(pathname, sizeof pathname, "%s%s%s", path,
> 			    strcmp(path, "/") ? "/" : "", dp->d_name);
> 			if (lstat(pathname, &st) < 0)
> 				continue;
>-			stat_to_attrib(&st, &(stats[count].attrib));
>-			stats[count].name = xstrdup(dp->d_name);
>-			stats[count].long_name = ls_file(dp->d_name, &st, 0, 0);
>+			stat_to_attrib(&st, &stats.attrib);
>+			stats.name = xstrdup(dp->d_name);
>+			stats.long_name = ls_file(dp->d_name, &st, 0, 0);
>+			stats.xa_size = 0;
>+			if (xattr_caching)
>+				stats.xa_size = get_xattr(pathname, &stats.xattrib);
>+			debug3("readdir: stats.xa_size=%ld", stats.xa_size);
>+			send_names_next(&msg, id, &stats);
>+			xfree(stats.name);
>+			xfree(stats.long_name);
>+			delete_xattr(stats.xattrib, stats.xa_size);
> 			count++;
>-			/* send up to 100 entries in one message */
>-			/* XXX check packet size instead */
>-			if (count == 100)
>+			if (buffer_len(&msg) + max_entrysize > SFTP_MAX_MSG_LENGTH)
> 				break;
> 		}
> 		if (count > 0) {
>-			send_names(id, count, stats);
>-			for (i = 0; i < count; i++) {
>-				xfree(stats[i].name);
>-				xfree(stats[i].long_name);
>-			}
>+			debug3("readdir: count=%d", count);
>+			send_names_end(&msg, count);
> 		} else {
>+			buffer_free(&msg);
> 			send_status(id, SSH2_FX_EOF);
> 		}
>-		xfree(stats);
> 	}
> }
> 
>@@ -1051,6 +1264,7 @@ process_realpath(void)
> 	} else {
> 		Stat s;
> 		attrib_clear(&s.attrib);
>+		s.xa_size = 0;
> 		s.name = s.long_name = resolvedname;
> 		send_names(id, 1, &s);
> 	}
>@@ -1138,6 +1352,7 @@ process_readlink(void)
> 
> 		buf[len] = '\0';
> 		attrib_clear(&s.attrib);
>+		s.xa_size = 0;
> 		s.name = s.long_name = buf;
> 		send_names(id, 1, &s);
> 	}
>@@ -1247,6 +1462,152 @@ process_extended_hardlink(u_int32_t id)
> }
> 
> static void
>+process_extended_setxattr(u_int32_t id)
>+{
>+	char *path, *name;
>+	void *value = NULL;
>+	u_int size;
>+	int pflags, ret, status;
>+
>+	path  = get_string(NULL);
>+	name  = get_string(NULL);
>+	value = get_string(&size);
>+	pflags = get_int();
>+	debug3("request %u: setxattr", id);
>+	if (readonly) {
>+		status = SSH2_FX_PERMISSION_DENIED;
>+		errno = EACCES;
>+	} else {
>+		int flags;
>+		flags  = (pflags & SSH2_FXE_XATTR_CREATE ) ? XATTR_CREATE  : 0;
>+		flags |= (pflags & SSH2_FXE_XATTR_REPLACE) ? XATTR_REPLACE : 0;
>+		logit("setxattr path \"%s\" name \"%s\" size=%d flags=%d", path, name, size, flags);
>+		ret = lsetxattr(path, name, value, size, flags);
>+		status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
>+	}
>+	send_status(id, status);
>+	xfree(path);
>+	xfree(name);
>+	xfree(value);
>+}
>+
>+void send_xattr_data (u_int32_t id, const char *data, size_t ret, size_t size) {
>+	if ((ret != (size_t)-1) && (ret > MAX_XATTR_DATA_LEN) && (size != 0)) {
>+		debug3("send_xattr_data EMSGSIZE: ret=%ld size=%ld ", ret, size);
>+		errno = EMSGSIZE;
>+		ret = (size_t)-1;
>+	}
>+	Buffer msg;
>+	buffer_init(&msg);
>+	buffer_put_char(&msg, SSH2_FXP_EXTENDED_REPLY);
>+	buffer_put_int(&msg, id);
>+	int err_no_p = errno_to_portable(errno);
>+	debug3("send_xattr_data ret=%ld errno=%d err_no_p=%d", ret, errno, err_no_p);
>+	buffer_put_int(&msg, ret);
>+	if (ret == (size_t)-1) {
>+		buffer_put_int(&msg, err_no_p);
>+	} else if (size != 0) {
>+		buffer_append(&msg, data, ret);
>+	}
>+	send_msg(&msg);
>+	buffer_free(&msg);
>+}
>+
>+static void
>+process_extended_getxattr(u_int32_t id)
>+{
>+	char *path, *name;
>+	size_t size;
>+	size_t ret;
>+
>+	path  = get_string(NULL);
>+	name  = get_string(NULL);
>+	size  = get_int();
>+	void *value = xmalloc(size+1);
>+
>+	debug3("request %u: getxattr", id);
>+	logit("getxattr path \"%s\" name \"%s\" size=%ld", path, name, size);
>+	ret = lgetxattr(path, name, value, size);
>+	send_xattr_data(id, value, ret, size);
>+	xfree(path);
>+	xfree(name);
>+	xfree(value);
>+}
>+
>+static void
>+process_extended_listxattr(u_int32_t id)
>+{
>+	char *path;
>+	size_t size;
>+	size_t ret;
>+
>+	path  = get_string(NULL);
>+	size  = get_int();
>+	void *list = xmalloc(size+1);
>+
>+	debug3("request %u: listxattr", id);
>+	logit("listxattr path \"%s\" size=%ld", path, size);
>+	ret = llistxattr(path, list, size);
>+	send_xattr_data(id, list, ret, size);
>+	xfree(path);
>+	xfree(list);
>+}
>+
>+static void
>+process_extended_removexattr(u_int32_t id)
>+{
>+	char *path, *name;
>+	int ret, status;
>+
>+	path  = get_string(NULL);
>+	name  = get_string(NULL);
>+	debug3("request %u: removexattr", id);
>+	logit("removexattr path \"%s\" name \"%s\"", path, name);
>+	if (readonly) {
>+		status = SSH2_FX_PERMISSION_DENIED;
>+		errno = EACCES;
>+	} else {
>+		ret = lremovexattr(path, name);
>+		status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
>+	}
>+	send_status(id, status);
>+	xfree(path);
>+	xfree(name);
>+}
>+
>+static void
>+process_extended_cachexattr(u_int32_t id)
>+{
>+	debug3("request %u: cachexattr", id);
>+	xattr_caching = 1;
>+	send_status(id, SSH2_FX_OK);
>+}
>+
>+static void
>+process_extended_getallxattr(u_int32_t id)
>+{
>+	char *path;
>+	Xattrib *xattrib;
>+	size_t xa_size;
>+
>+	path  = get_string(NULL);
>+	debug3("request %u: getallxattr", id);
>+	logit("getallxattr path \"%s\"", path);
>+	xa_size = get_xattr(path, &xattrib);
>+	debug3("getallxattr: xa_size=%ld", xa_size);
>+
>+	Buffer msg;
>+	buffer_init(&msg);
>+	buffer_put_char(&msg, SSH2_FXP_EXTENDED_REPLY);
>+	buffer_put_int(&msg, id);
>+	write_allxattr_data(&msg, xattrib, xa_size);
>+	send_msg(&msg);
>+	buffer_free(&msg);
>+	xfree(path);
>+	delete_xattr(xattrib, xa_size);
>+}
>+
>+static void
> process_extended(void)
> {
> 	u_int32_t id;
>@@ -1262,6 +1623,18 @@ process_extended(void)
> 		process_extended_fstatvfs(id);
> 	else if (strcmp(request, "hardlink@openssh.com") == 0)
> 		process_extended_hardlink(id);
>+	else if (strcmp(request, "setxattr@openssh.com") == 0)
>+		process_extended_setxattr(id);
>+	else if (strcmp(request, "getxattr@openssh.com") == 0)
>+		process_extended_getxattr(id);
>+	else if (strcmp(request, "listxattr@openssh.com") == 0)
>+		process_extended_listxattr(id);
>+	else if (strcmp(request, "removexattr@openssh.com") == 0)
>+		process_extended_removexattr(id);
>+	else if (strcmp(request, "cachexattr@openssh.com") == 0)
>+		process_extended_cachexattr(id);
>+	else if (strcmp(request, "getallxattr@openssh.com") == 0)
>+		process_extended_getallxattr(id);
> 	else
> 		send_status(id, SSH2_FX_OP_UNSUPPORTED);	/* MUST */
> 	xfree(request);
>@@ -1293,6 +1666,7 @@ process(void)
> 	buffer_consume(&iqueue, 4);
> 	buf_len -= 4;
> 	type = buffer_get_char(&iqueue);
>+	debug3("request type: %d", type);
> 	switch (type) {
> 	case SSH2_FXP_INIT:
> 		process_init();
>diff -rupN openssh-5.9p1/sftp.h openssh-5.9p1_mod_xattr/sftp.h
>--- openssh-5.9p1/sftp.h	2008-06-13 02:22:54.000000000 +0200
>+++ openssh-5.9p1_mod_xattr/sftp.h	2011-11-08 15:03:41.490347612 +0100
>@@ -83,6 +83,10 @@
> #define SSH2_FXE_STATVFS_ST_RDONLY	0x00000001
> #define SSH2_FXE_STATVFS_ST_NOSUID	0x00000002
> 
>+/* xattr@openssh.com flags */
>+#define SSH2_FXE_XATTR_CREATE		0x00000001
>+#define SSH2_FXE_XATTR_REPLACE		0x00000002
>+
> /* status messages */
> #define SSH2_FX_OK			0
> #define SSH2_FX_EOF			1
>@@ -93,7 +97,12 @@
> #define SSH2_FX_NO_CONNECTION		6
> #define SSH2_FX_CONNECTION_LOST		7
> #define SSH2_FX_OP_UNSUPPORTED		8
>-#define SSH2_FX_MAX			8
>+#define SSH2_FX_ENOATTR                 9
>+#define SSH2_FX_ENOSPC                 10
>+#define SSH2_FX_ENOTSUP                11
>+#define SSH2_FX_ERANGE                 12
>+#define SSH2_FX_EMSGSIZE               13
>+#define SSH2_FX_MAX		       13
> 
> struct passwd;
>

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