0.6.2: okrun opens a relative image name that climbs (..)

.github/workflows/ci.yml

@@ -288,6 +288,15 @@ jobs:
           grep -q "argc as kal_env_arg_count = 3" <<<"$out" || { echo "::error::the image's arguments"; exit 1; }
           grep -q "mix = 204" <<<"$out" || { echo "::error::the calling convention"; exit 1; }
           grep -q "tls main=1 ctx1=10 ctx2=20" <<<"$out" || { echo "::error::thread-local storage or the callback"; exit 1; }
+          # A RELATIVE NAME THAT CLIMBS (0.6.2): `..' above the working
+          # directory folds against its name and opens through the supplied
+          # directory that then holds it; `./' beside it and an absolute name
+          # already ran.
+          mkdir -p rel/below
+          (cd rel/below && "$OKRUN" ../../"out/$a/hello.oke" one | tr -d '\r' \
+            | grep -q "argc as kal_env_arg_count = 2") \
+            || { echo "::error::a relative image name with .. was not opened"; exit 1; }
+          echo "  ok  a relative name that climbs opens the image"
           n=$("$OKRUN" "out/$a/needed.oke" | tr -d '\r')
           echo "$n"
           grep -q "twice(21) = 42, next_value() = 41" <<<"$n" || { echo "::error::an image another needs"; exit 1; }

README.md

@@ -76,6 +76,14 @@ states the system's base), where openkal-freebsd is hosted, and over
 openkal-musl (`<arch>-freebsd-musl`), whose graph already holds openkal-freebsd
 standalone. No other change.
 
+Version 0.6.2 opens an image whose relative name climbs above the working
+directory (`../image.oke`). Such a name was passed to the file system as it
+stood, and an openkal name admits no `..` component, so the image was refused.
+The runner now folds a relative name against the first directory's name ---
+`..' and `.' lexically, a symlink left to the file system --- into the absolute
+name beneath it, which is matched against the supplied directories as an
+absolute one is. No other change.
+
 ## An image
 
 ```sh

bind/mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-bind"
-version     = "0.6.1"
+version     = "0.6.2"
 # `mcpp::xpkg_request', `mcpp::decision' (protocol 15).
 mcpp        = ">=2026.10.1.3"
 description = "A build plugin: a library published as an ok image (.okso) and a C header is called from a program of any system, through a binding generated from the header and libokrun."

ld/mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-ld"
-version     = "0.6.1"
+version     = "0.6.2"
 description = "libokld: the ok format (openkal image format) --- its definition, a reader of bytes, a checker, a signer, and a loader. Freestanding: no C library, no exceptions."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]

run/mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-run"
-version     = "0.6.1"
+version     = "0.6.2"
 description = "libokrun: the runner's core --- an ok image's names bound to this process's one openkal implementation, in the image's calling convention, and its entry entered."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]

run/src/run.cpp

@@ -67,33 +67,61 @@ void* allocate(okld_size n, void*) { return kal_alloc(n, 16); }
 void deallocate(void* p, okld_size n, void*) { kal_free(p, n, 16); }
 
 // A name as openkal names things: the supplied directory that is the longest
-// prefix of it, and the rest. A relative name is beneath the first.
+// prefix of it, and the rest. A relative name is folded against the first
+// directory's name --- `..' and `.' lexically, a symlink not resolved --- into
+// the absolute one beneath it and matched as that. It folds into `g_folded',
+// which outlives the call: the rest points into it.
 bool separator(char c) { return c == '/' || c == '\\'; }
 char lower(char c) { return (c >= 'A' && c <= 'Z') ? static_cast<char>(c - 'A' + 'a') : c; }
 
+char g_folded[1024];
+
 bool locate(const char* path, kal_dir& dir, const char*& rest) {
-    const bool absolute = separator(path[0]) || (path[0] && path[1] == ':');
-    if (!absolute) {
-        char name[8]; kal_uintptr len = 0;
-        if (kal_fs_preopen(0, &dir, name, sizeof name, &len) != kal_ok) return false;
-        rest = path;
-        while (rest[0] == '.' && separator(rest[1])) rest += 2;
-        return true;
+    const char* name = path;
+    if (!(separator(path[0]) || (path[0] && path[1] == ':'))) {
+        char base[1024]; kal_uintptr blen = 0;
+        if (kal_fs_preopen(0, &dir, base, sizeof base, &blen) != kal_ok
+            || blen == 0 || blen >= sizeof g_folded) return false;
+        unsigned long at = 0;
+        while (at < blen) { g_folded[at] = base[at]; ++at; }
+        if (!separator(g_folded[at - 1])) g_folded[at++] = '/';
+        // `..' may climb out of the first directory, to the root of what it
+        // then names: the whole tree, or a drive's. No higher.
+        unsigned long floor = at;
+        if (blen > 1 && separator(g_folded[0])) floor = 1;
+        else if (blen > 3 && g_folded[1] == ':' && separator(g_folded[2])) floor = 3;
+        for (const char* p = path; *p;) {
+            const char* s = p;
+            while (*p && !separator(*p)) ++p;
+            const unsigned long n = static_cast<unsigned long>(p - s);
+            while (separator(*p)) ++p;
+            if (n == 0 || (n == 1 && s[0] == '.')) continue;
+            if (n == 2 && s[0] == '.' && s[1] == '.') {
+                if (at <= floor) return false;
+                do --at; while (at > floor && !separator(g_folded[at - 1]));
+                continue;
+            }
+            if (at && !separator(g_folded[at - 1])) g_folded[at++] = '/';
+            if (at + n >= sizeof g_folded) return false;
+            for (unsigned long i = 0; i < n; ++i) g_folded[at++] = s[i];
+        }
+        g_folded[at] = 0;
+        name = g_folded;
     }
     unsigned long best = 0;
     bool found = false;
     for (kal_uintptr i = 0; i < kal_fs_preopen_count(); ++i) {
-        kal_dir d{}; char name[1024]; kal_uintptr len = 0;
-        if (kal_fs_preopen(i, &d, name, sizeof name, &len) != kal_ok || len == 0 || len >= sizeof name) continue;
+        kal_dir d{}; char pname[1024]; kal_uintptr len = 0;
+        if (kal_fs_preopen(i, &d, pname, sizeof pname, &len) != kal_ok || len == 0 || len >= sizeof pname) continue;
         unsigned long k = 0;
-        while (k < len && path[k] && (lower(path[k]) == lower(name[k]) || (separator(path[k]) && separator(name[k])))) ++k;
+        while (k < len && name[k] && (lower(name[k]) == lower(pname[k]) || (separator(name[k]) && separator(pname[k])))) ++k;
         if (k != len) continue;
-        if (!separator(name[len - 1]) && path[len] && !separator(path[len])) continue;
+        if (!separator(pname[len - 1]) && name[len] && !separator(name[len])) continue;
         if (found && len <= best) continue;
         best = len; found = true; dir = d;
     }
     if (!found) return false;
-    rest = path + best;
+    rest = name + best;
     while (separator(*rest)) ++rest;
     return true;
 }

tools/mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-tools"
-version     = "0.6.1"
+version     = "0.6.2"
 description = "okrun, which runs an ok image on this system, and okld, the format's tool on a build machine (check, note, sign, inspect)."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]