path: add new "systemd-path" utility for querying paths described in file-hierarchy(7)

This new tool is based on "sd-path", a new (so far unexported) API for
libsystemd, that can hopefully grow into a workable API covering /opt
and more one day.

4 files changed, 87 insertions, 4 deletions

diff --git a/src/shared/architecture.h b/src/shared/architecture.h
index 20e848bd8f..08079244dc 100644
--- a/src/shared/architecture.h
+++ b/src/shared/architecture.h
@@ -23,6 +23,8 @@
 
 #include "util.h"
 
+/* A cleaned up architecture definition */
+
 typedef enum Architecture {
         ARCHITECTURE_X86 = 0,
         ARCHITECTURE_X86_64,
@@ -38,7 +40,9 @@ typedef enum Architecture {
         ARCHITECTURE_SPARC,
         ARCHITECTURE_SPARC64,
         ARCHITECTURE_MIPS,
+        ARCHITECTURE_MIPS_LE,
         ARCHITECTURE_MIPS64,
+        ARCHITECTURE_MIPS64_LE,
         ARCHITECTURE_ALPHA,
         ARCHITECTURE_ARM,
         ARCHITECTURE_ARM_BE,
@@ -55,64 +59,107 @@ typedef enum Architecture {
 
 Architecture uname_architecture(void);
 
+/*
+ * ARCH_TUPLE should resolve to the local architecture systemd is
+ * built for, according to the Debian tuple list:
+ *
+ * https://wiki.debian.org/Multiarch/Tuples
+ *
+ */
+
 #if defined(__x86_64__)
 #  define native_architecture() ARCHITECTURE_X86_64
+#  define ARCH_TUPLE "x86_64-linux-gnu"
 #elif defined(__i386__)
 #  define native_architecture() ARCHITECTURE_X86
+#  define ARCH_TUPLE "i386-linux-gnu"
 #elif defined(__powerpc64__)
 #  if defined(WORDS_BIGENDIAN)
 #    define native_architecture() ARCHITECTURE_PPC64
+#    define ARCH_TUPLE "ppc64-linux-gnu"
 #  else
 #    define native_architecture() ARCHITECTURE_PPC64_LE
+#    error "Missing ARCH_TUPLE for PPC64LE"
 #  endif
 #elif defined(__powerpc__)
 #  if defined(WORDS_BIGENDIAN)
 #    define native_architecture() ARCHITECTURE_PPC
+#    define ARCH_TUPLE "powerpc-linux-gnu"
 #  else
 #    define native_architecture() ARCHITECTURE_PPC_LE
+#    error "Missing ARCH_TUPLE for PPCLE"
 #  endif
 #elif defined(__ia64__)
 #  define native_architecture() ARCHITECTURE_IA64
+#  define ARCH_TUPLE "ia64-linux-gnu"
 #elif defined(__hppa64__)
 #  define native_architecture() ARCHITECTURE_PARISC64
+#  error "Missing ARCH_TUPLE for HPPA64"
 #elif defined(__hppa__)
 #  define native_architecture() ARCHITECTURE_PARISC
+#  define ARCH_TUPLE "hppa‑linux‑gnu"
 #elif defined(__s390x__)
 #  define native_architecture() ARCHITECTURE_S390X
+#  define ARCH_TUPLE "s390x-linux-gnu"
 #elif defined(__s390__)
 #  define native_architecture() ARCHITECTURE_S390
+#  define ARCH_TUPLE "s390-linux-gnu"
 #elif defined(__sparc64__)
 #  define native_architecture() ARCHITECTURE_SPARC64
+#  define ARCH_TUPLE "sparc64-linux-gnu"
 #elif defined(__sparc__)
 #  define native_architecture() ARCHITECTURE_SPARC
+#  define ARCH_TUPLE "sparc-linux-gnu"
 #elif defined(__mips64__)
-#  define native_architecture() ARCHITECTURE_MIPS64
+#  if defined(WORDS_BIGENDIAN)
+#    define native_architecture() ARCHITECTURE_MIPS64
+#    error "Missing ARCH_TUPLE for MIPS64"
+#  else
+#    define native_architecture() ARCHITECTURE_MIPS64_LE
+#    error "Missing ARCH_TUPLE for MIPS64_LE"
+#  endif
 #elif defined(__mips__)
-#  define native_architecture() ARCHITECTURE_MIPS
+#  if defined(WORDS_BIGENDIAN)
+#    define native_architecture() ARCHITECTURE_MIPS
+#    define ARCH_TUPLE "mips-linux-gnu"
+#  else
+#    define native_architecture() ARCHITECTURE_MIPS_LE
+#    define ARCH_TUPLE "mipsel-linux-gnu"
+#endif
 #elif defined(__alpha__)
 #  define native_architecture() ARCHITECTURE_ALPHA
+#  define ARCH_TUPLE "alpha-linux-gnu"
 #elif defined(__aarch64__)
 #  if defined(WORDS_BIGENDIAN)
 #    define native_architecture() ARCHITECTURE_ARM64_BE
+#    define ARCH_TUPLE "aarch64_be-linux-gnu"
 #  else
 #    define native_architecture() ARCHITECTURE_ARM64
+#    define ARCH_TUPLE "aarch64-linux-gnu"
 #  endif
 #elif defined(__arm__)
 #  if defined(WORDS_BIGENDIAN)
 #    define native_architecture() ARCHITECTURE_ARM_BE
+#    error "Missing ARCH_TUPLE for ARM_BE"
 #  else
 #    define native_architecture() ARCHITECTURE_ARM
+#    error "Missing ARCH_TUPLE for ARM"
 #  endif
 #elif defined(__sh64__)
 #  define native_architecture() ARCHITECTURE_SH64
+#  error "Missing ARCH_TUPLE for SH64"
 #elif defined(__sh__)
 #  define native_architecture() ARCHITECTURE_SH
+#  define ARCH_TUPLE "sh4-linux-gnu"
 #elif defined(__m68k__)
 #  define native_architecture() ARCHITECTURE_M68K
+#  define ARCH_TUPLE "m68k-linux-gnu"
 #elif defined(__tilegx__)
 #  define native_architecture() ARCHITECTURE_TILEGX
+#  error "Missing ARCH_TUPLE for TILEGX"
 #elif defined(__cris__)
 #  define native_architecture() ARCHITECTURE_CRIS
+#  error "Missing ARCH_TUPLE for CRIS"
 #else
 #error "Please register your architecture here!"
 #endif
diff --git a/src/shared/strv.c b/src/shared/strv.c
index 1ef0b26a25..b4c476eff2 100644
--- a/src/shared/strv.c
+++ b/src/shared/strv.c
@@ -378,6 +378,30 @@ int strv_push(char ***l, char *value) {
         return 0;
 }
 
+int strv_push_prepend(char ***l, char *value) {
+        char **c;
+        unsigned n, i;
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+        c = new(char*, n + 2);
+        if (!c)
+                return -ENOMEM;
+
+        for (i = 0; i < n; i++)
+                c[i+1] = (*l)[i];
+
+        c[0] = value;
+        c[n+1] = NULL;
+
+        free(*l);
+        *l = c;
+
+        return 0;
+}
+
 int strv_consume(char ***l, char *value) {
         int r;
 
@@ -388,6 +412,16 @@ int strv_consume(char ***l, char *value) {
         return r;
 }
 
+int strv_consume_prepend(char ***l, char *value) {
+        int r;
+
+        r = strv_push_prepend(l, value);
+        if (r < 0)
+                free(value);
+
+        return r;
+}
+
 int strv_extend(char ***l, const char *value) {
         char *v;
 
diff --git a/src/shared/strv.h b/src/shared/strv.h
index e26ab828d2..3034073d32 100644
--- a/src/shared/strv.h
+++ b/src/shared/strv.h
@@ -41,7 +41,9 @@ int strv_extend_strv_concat(char ***a, char **b, const char *suffix);
 int strv_extend(char ***l, const char *value);
 int strv_extendf(char ***l, const char *format, ...) _printf_(2,0);
 int strv_push(char ***l, char *value);
+int strv_push_prepend(char ***l, char *value);
 int strv_consume(char ***l, char *value);
+int strv_consume_prepend(char ***l, char *value);
 
 char **strv_remove(char **l, const char *s);
 char **strv_uniq(char **l);
diff --git a/src/shared/util.c b/src/shared/util.c
index 9b5a47ab6f..a1c8baf237 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -5226,8 +5226,8 @@ int get_home_dir(char **_h) {
         assert(_h);
 
         /* Take the user specified one */
-        e = getenv("HOME");
-        if (e) {
+        e = secure_getenv("HOME");
+        if (e && path_is_absolute(e)) {
                 h = strdup(e);
                 if (!h)
                         return -ENOMEM;