driver: implemented and integrated the -H (follow symlink args) cmdline option.

7 files changed, 112 insertions, 4 deletions

diff --git a/include/tpax/tpax.h b/include/tpax/tpax.h
index 2938d92..ec44b41 100644
--- a/include/tpax/tpax.h
+++ b/include/tpax/tpax.h
@@ -56,6 +56,7 @@ extern "C" {
 
 #define TPAX_DRIVER_PRESERVE_ATIME	0x1000000
 #define TPAX_DRIVER_PRESERVE_MTIME	0x2000000
+#define TPAX_DRIVER_PAX_SYMLINK_ARGS    0x4000000
 
 /* error flags */
 #define TPAX_ERROR_TOP_LEVEL		0x0001
diff --git a/src/driver/tpax_driver_ctx.c b/src/driver/tpax_driver_ctx.c
index e8ecb9e..71b4656 100644
--- a/src/driver/tpax_driver_ctx.c
+++ b/src/driver/tpax_driver_ctx.c
@@ -530,6 +530,10 @@ int tpax_lib_get_driver_ctx(
 					cctx.drvflags |= TPAX_DRIVER_PRESERVE_ATIME;
 					break;
 
+				case TAG_PAX_SYMLINK_ARGS:
+					cctx.drvflags |= TPAX_DRIVER_PAX_SYMLINK_ARGS;
+					break;
+
 				case TAG_STRICT_PATH:
 					cctx.drvflags |= TPAX_DRIVER_STRICT_PATH_INPUT;
 					break;
diff --git a/src/internal/tpax_driver_impl.h b/src/internal/tpax_driver_impl.h
index 1e898e9..a074535 100644
--- a/src/internal/tpax_driver_impl.h
+++ b/src/internal/tpax_driver_impl.h
@@ -28,6 +28,8 @@
 
 #define TPAX_ITEM_EXPLICIT 0X1
 #define TPAX_ITEM_IMPLICIT 0X2
+#define TPAX_ITEM_SYMLINK  0X4
+#define TPAX_ITEM_NAMEREF  0x8
 
 extern const struct argv_option tpax_default_options[];
 
@@ -46,6 +48,7 @@ enum app_tags {
 	TAG_STRICT_PATH,
 	TAG_PURE_PATH,
 	TAG_PRESERVE_ATIME,
+	TAG_PAX_SYMLINK_ARGS,
 };
 
 struct tpax_dirent {
diff --git a/src/logic/tpax_archive_enqueue.c b/src/logic/tpax_archive_enqueue.c
index 222b0ad..b81661b 100644
--- a/src/logic/tpax_archive_enqueue.c
+++ b/src/logic/tpax_archive_enqueue.c
@@ -400,6 +400,7 @@ int tpax_archive_enqueue(
 	const struct tpax_unit_ctx *    uctx)
 {
 	int                             fdat;
+	int                             fdlnk;
 	uintptr_t                       addr;
 	const char *                    name;
 	const char *                    mark;
@@ -409,11 +410,15 @@ int tpax_archive_enqueue(
 	struct tpax_dirent *            cdent;
 	struct tpax_dirent *            cnext;
 	struct dirent *                 dirent;
+	struct dirent *                 lnkent;
+	struct stat                     lnkst;
 	char                            entbuf[PATH_MAX + sizeof(struct dirent)];
+	char                            lnkbuf[PATH_MAX + sizeof(struct dirent)];
 
 	/* init */
 	fdat   = tpax_driver_fdcwd(dctx);
 	dirent = (struct dirent *)entbuf;
+	lnkent = (struct dirent *)lnkbuf;
 	prefix = 0;
 
 	/* split path to prefix + basename */
@@ -449,6 +454,39 @@ int tpax_archive_enqueue(
 			TPAX_NESTED_ERROR(dctx),
 			0);
 
+	/* follow command-line symlink arguments as needed */
+	fdlnk = (uctx->link[0] && (dctx->cctx->drvflags & TPAX_DRIVER_PAX_SYMLINK_ARGS))
+		? openat(fdat,uctx->link[0],O_RDONLY|O_CLOEXEC) : (-1);
+
+	if (fdlnk >= 0) {
+		if (fstat(fdlnk,&lnkst) <0) {
+			close(fdlnk);
+			return tpax_archive_enqueue_ret(
+				TPAX_SYSTEM_ERROR(dctx),
+				0);
+		}
+
+		close(fdlnk);
+
+		if (tpax_dirent_init_from_uctx(&lnkst,uctx->link[0],lnkent) < 0)
+			return tpax_archive_enqueue_ret(
+				TPAX_CUSTOM_ERROR(
+					dctx,
+					TPAX_ERR_FLOW_ERROR),
+				0);
+
+		cdent = tpax_get_driver_dirmark(dctx);
+		cdent->flags |= TPAX_ITEM_NAMEREF;
+
+		if (tpax_archive_add_queue_item(
+				dctx,lnkent,cdent,0,1,
+				TPAX_ITEM_EXPLICIT|TPAX_ITEM_SYMLINK,
+				fdat,&fkeep) < 0)
+			return tpax_archive_enqueue_ret(
+				TPAX_NESTED_ERROR(dctx),
+				0);
+	}
+
 	/* queue directory child items */
 	dentbuf = tpax_get_driver_dirents(dctx);
 	cdent   = tpax_get_driver_dirmark(dctx);
diff --git a/src/logic/tpax_archive_write.c b/src/logic/tpax_archive_write.c
index 1a641bf..98d7dfc 100644
--- a/src/logic/tpax_archive_write.c
+++ b/src/logic/tpax_archive_write.c
@@ -80,8 +80,10 @@ static int tpax_archive_write_impl(
 	struct tpax_unit_ctx *          uctx;
 	struct tpax_ustar_header        uhdr;
 	const struct stat *             st;
+	struct stat                     stbuf;
 	const  char *                   path;
 	const  char *                   slnk;
+	const  char *                   mlnk;
 	off_t                           hpos;
 	off_t                           dpos;
 	int                             fdtmp;
@@ -91,6 +93,12 @@ static int tpax_archive_write_impl(
 	size_t                          buflen;
 	size_t                          cmplen;
 	void *				membuf;
+	char *                          ch;
+	char                           	pathbuf[PATH_MAX];
+
+	/* followed symlink? */
+	if (cdent->flags & TPAX_ITEM_NAMEREF)
+		return 0;
 
 	/* full path */
 	if (!(path = tpax_queue_item_full_path(dctx,cdent)))
@@ -104,6 +112,44 @@ static int tpax_archive_write_impl(
 
 	st   = uctx->st;
 	slnk = uctx->link[0];
+	mlnk = 0;
+
+	if (cdent->flags & TPAX_ITEM_SYMLINK) {
+		st   = &stbuf;
+		mlnk = slnk;
+		slnk = 0;
+		ch   = 0;
+
+		if (mlnk[0] != '/') {
+			if (strlen(path) >= PATH_MAX)
+				return tpax_archive_write_ret(
+					TPAX_CUSTOM_ERROR(
+						dctx,
+						TPAX_ERR_FLOW_ERROR),
+					uctx);
+
+			strcpy(pathbuf,path);
+
+			ch = strrchr(pathbuf,'/');
+		}
+
+		if (ch && (++ch - pathbuf >= PATH_MAX))
+			return tpax_archive_write_ret(
+				TPAX_CUSTOM_ERROR(
+					dctx,
+					TPAX_ERR_FLOW_ERROR),
+				uctx);
+
+		if (ch) {
+			strcpy(ch,mlnk);
+			mlnk = pathbuf;
+		}
+
+		if (fstatat(fdcwd,mlnk,&stbuf,0) < 0)
+			return tpax_archive_write_ret(
+				TPAX_SYSTEM_ERROR(dctx),
+				uctx);
+	}
 
 	/* record errors */
 	tpax_driver_set_ectx(
@@ -136,14 +182,16 @@ static int tpax_archive_write_impl(
 		/* snapshot */
 		if (membuf) {
 			if (tpax_io_create_memory_snapshot(
-					dctx,fdcwd,path,
+					dctx,fdcwd,
+					mlnk ? mlnk : path,
 					st,membuf) < 0)
 				return tpax_archive_write_ret(
 					TPAX_NESTED_ERROR(dctx),
 					uctx);
 		} else {
 			if ((fdtmp = tpax_io_create_tmpfs_snapshot(
-					dctx,fdcwd,path,
+					dctx,fdcwd,
+					mlnk ? mlnk : path,
 					st)) < 0)
 				return tpax_archive_write_ret(
 					TPAX_NESTED_ERROR(dctx),
diff --git a/src/logic/tpax_queue_vector.c b/src/logic/tpax_queue_vector.c
index 82930b1..cae4da0 100644
--- a/src/logic/tpax_queue_vector.c
+++ b/src/logic/tpax_queue_vector.c
@@ -38,11 +38,17 @@ tpax_hidden const char * tpax_queue_item_full_path(
 		ch += sprintf(ch,"%s",pdirent[0]->prefix);
 
 	for (; pdirent > dirstck; ) {
-		ch += sprintf(ch,"%s/",pdirent[0]->dirent.d_name);
+		if (!(pdirent[0]->flags & TPAX_ITEM_SYMLINK))
+			ch += sprintf(ch,"%s/",pdirent[0]->dirent.d_name);
+
 		pdirent--;
 	}
 
-	sprintf(ch,"%s",pdirent[0]->dirent.d_name);
+	if (pdirent[0]->flags & TPAX_ITEM_SYMLINK) {
+		*--ch = '\0';
+	} else {
+		sprintf(ch,"%s",pdirent[0]->dirent.d_name);
+	}
 
 	return pathbuf;
 }
diff --git a/src/skin/tpax_skin_default.c b/src/skin/tpax_skin_default.c
index 1684553..5bddb70 100644
--- a/src/skin/tpax_skin_default.c
+++ b/src/skin/tpax_skin_default.c
@@ -66,6 +66,14 @@ const tpax_hidden struct argv_option tpax_default_options[] = {
 			"time that was reported by fstatat(3) prior to the "
 			"first read operation performed by pax"},
 
+	{"Wpax-symlink-args",
+			'H',TAG_PAX_SYMLINK_ARGS,ARGV_OPTARG_NONE,
+			ARGV_OPTION_HYBRID_ONLY,0,0,
+			"when a command-line argument is a symbolic link, "
+			"add the underlying (referenced) file-system object "
+			"or directory to the archive using the name of the "
+			"symbolic link."},
+
 	{"Wstrict-path-input",
 			0,TAG_STRICT_PATH,ARGV_OPTARG_NONE,
 			ARGV_OPTION_HYBRID_ONLY,0,0,