From a7fc0edabecbb4fbd89708e19f232889c0da2b0b Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Mon, 20 Nov 1995 07:19:40 +0000
Subject: [PATCH] make dlopen() use hints database, not just paths; from
 etheisen@TECLink.Net; netbsd pr#1763

---
 gnu/usr.bin/ld/rtld/rtld.c | 103 +++++++++++++++++++++++++++++++++++--
 share/man/man3/dlfcn.3     |  11 ++--
 2 files changed, 105 insertions(+), 9 deletions(-)

diff --git a/gnu/usr.bin/ld/rtld/rtld.c b/gnu/usr.bin/ld/rtld/rtld.c
index 72194af2d7d..33b5cd76551 100644
--- a/gnu/usr.bin/ld/rtld/rtld.c
+++ b/gnu/usr.bin/ld/rtld/rtld.c
@@ -1331,6 +1331,103 @@ static struct so_map dlmap = {
 };
 static int dlerrno;
 
+/*
+ * Populate sod struct for dlopen's call to map_obj
+ */
+void
+build_sod(name, sodp)
+	char		*name;
+	struct	sod	*sodp;
+{
+	unsigned int	number;
+	unsigned int	tuplet;
+	unsigned int	strange = 0;
+	int		major, minor;
+	char		*realname, *tok, *tok1;
+
+	/* default is an absolute or relative path */
+	sodp->sod_name = (long)strdup(name);	/* strtok is destructive */
+	sodp->sod_library = 0;
+	sodp->sod_major = sodp->sod_minor = 0;
+	/* asking for lookup? */
+	if (strncmp((char *)sodp->sod_name, "lib", 3) == NULL) {
+		/* skip over 'lib' */
+		tok = (char *)sodp->sod_name + 3;
+		/* dot guardian */
+		if((strchr(tok, '.') != NULL) && (*(tok+strlen(tok)-1)!='.')) {
+			tok = strtok(tok, ".");
+			/* default */
+			major = minor = -1;
+			/* removed 'lib' and extensions from name */
+			realname = tok;
+			/* loop through name - parse skipping name */
+			for(tuplet=1;((tok=strtok(NULL,"."))!=NULL);tuplet++) {
+				switch (tuplet) {
+					/* 'so' extension */
+					case 1:
+						if(strcmp(tok, "so") != NULL)
+							strange = 1;
+						break;
+					/* major ver extension */
+					case 2:
+						for(tok1=tok;
+						    (*tok1 != '\0');
+						    tok1++) {
+							if(isdigit(*tok1))
+								number = 1;
+							else {
+								number = 0;
+								break;
+							}
+						}
+						if(number)
+							major = atoi(tok);
+						else {
+							major = 0;
+							strange = 1;
+						}
+						break;
+					/* minor ver extension */
+					case 3:
+						for(tok1=tok;
+						    (*tok1 != '\0');
+						    tok1++) {
+							if(isdigit(*tok1))
+								number = 1;
+							else {
+								number = 0;
+								break;
+							}
+						}
+						if(number)
+							minor = atoi(tok);
+						else {
+							minor = 0;
+							strange = 1;
+						}
+						break;
+					/* if we get here, it must be weird */
+					default:
+						strange = 1;
+				} /* end switch */
+			} /* end for */
+			/* normal */
+			if(!strange) {
+				free((char *)sodp->sod_name);
+				sodp->sod_name = (long)strdup(realname);
+				sodp->sod_library = 1;
+				sodp->sod_major = major;
+				sodp->sod_minor = minor;
+			}
+			/* strange */
+			else {
+				free((char *)sodp->sod_name);
+				sodp->sod_name = (long)strdup(name);
+			}
+		} /* end if dots */
+	}  /* end if lookup */
+}
+
 static void *
 __dlopen(name, mode)
 	char	*name;
@@ -1352,11 +1449,9 @@ __dlopen(name, mode)
 		return NULL;
 	}
 
-	sodp->sod_name = (long)strdup(name);
-	sodp->sod_library = 0;
-	sodp->sod_major = sodp->sod_minor = 0;
+	build_sod(name, sodp);
 
-	if ((smp = map_object(name, sodp, 0)) == NULL) {
+	if ((smp = map_object((char *)sodp->sod_name, sodp, 0)) == NULL) {
 #ifdef DEBUG
 xprintf("%s: %s\n", name, strerror(errno));
 #endif
diff --git a/share/man/man3/dlfcn.3 b/share/man/man3/dlfcn.3
index 3c36a96bbee..39047b975a5 100644
--- a/share/man/man3/dlfcn.3
+++ b/share/man/man3/dlfcn.3
@@ -41,7 +41,7 @@
 .Sh SYNOPSIS
 .Fd #include <dlfcn.h>
 .Ft "void *"
-.Fn dlopen "char *path" "int mode"
+.Fn dlopen "char *name" "int mode"
 .Ft "int"
 .Fn dlclose "void *handle"
 .Ft "void *"
@@ -57,10 +57,11 @@ They allow new shared objects to be loaded into the process' address space
 under program control.
 The
 .Fn dlopen
-function takes a pathname of a shared object as the first argument. The
-shared object is mapped into the address space, relocated and its external
-references are resolved in the same way as is done with the implicitly loaded
-shared libraries at program startup.
+function takes a filename of the forms 'libname.so', 'libname.so.xx.xx' where
+xx are the major and minor revisions, or 'pathname/filename' of a shared object
+as the first argument. The shared object is mapped into the address space,
+relocated and its external references are resolved in the same way as is done
+with the implicitly loaded shared libraries at program startup.
 The second argument has currently no effect, but should be set to
 .Dv DL_LAZY
 for future compatibility.
-- 
2.20.1