Implement error handling

* Die on bad root directory

8 files changed, 67 insertions, 17 deletions

diff --git a/include/conf.h b/include/conf.h
index a5a4d36..7952eed 100644
--- a/include/conf.h
+++ b/include/conf.h
@@ -16,6 +16,7 @@ typedef struct {
 } ConfigItem;
 
 typedef struct {
+    char *rootrec;
     char *rootdir;
     char *bindir;
     char *includedir;
diff --git a/include/install.h b/include/install.h
index fb08661..bc1fe19 100644
--- a/include/install.h
+++ b/include/install.h
@@ -4,6 +4,8 @@
 #ifndef SPM_INSTALL_H
 #define SPM_INSTALL_H
 
+int spm_hierarchy_is_root(SPM_Hierarchy *fs);
+int spm_hierarchy_make_root(SPM_Hierarchy *fs);
 void spm_install_show_package(ManifestPackage *package);
 int spm_install(SPM_Hierarchy *fs, const char *tmpdir, const char *_package);
 int spm_install_package_record(SPM_Hierarchy *fs, char *tmpdir, char *package_name);
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index fd5c905..2185ef4 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -30,6 +30,7 @@ set(libspm_src
 	user_input.c
 	metadata.c
 	purge.c
+	error_handler.c
 )
 
 add_library(libspm_obj OBJECT ${libspm_src})
diff --git a/lib/config_global.c b/lib/config_global.c
index f63566b..e97cddb 100644
--- a/lib/config_global.c
+++ b/lib/config_global.c
@@ -153,7 +153,7 @@ void check_runtime_environment(void) {
 }
 
 /**
- *
+ * Define the structure of a SPM root hierarchy
  * @param basepath
  * @return
  */
@@ -170,12 +170,13 @@ SPM_Hierarchy *spm_hierarchy_init(char *basepath) {
     fs->tmpdir = join((char *[]) {fs->rootdir, "tmp", NULL}, DIRSEPS);
     fs->dbdir = join((char *[]) {fs->localstatedir, "db", NULL}, DIRSEPS);
     fs->dbrecdir = join((char *[]) {fs->dbdir, "records", NULL}, DIRSEPS);
+    fs->rootrec = join((char *[]) {".spm_root", NULL}, DIRSEPS);
 
     return fs;
 }
 
 /**
- *
+ * Free SPM_Hierarchy structure
  * @param fs
  */
 void spm_hierarchy_free(SPM_Hierarchy *fs) {
@@ -190,6 +191,7 @@ void spm_hierarchy_free(SPM_Hierarchy *fs) {
     free(fs->tmpdir);
     free(fs->dbdir);
     free(fs->dbrecdir);
+    free(fs->rootrec);
     free(fs);
 }
 
diff --git a/lib/fs.c b/lib/fs.c
index 3ba01e7..20a5999 100644
--- a/lib/fs.c
+++ b/lib/fs.c
@@ -624,7 +624,6 @@ char *spm_mkdtemp(const char *base, const char *name, const char *extended_path)
      path_stat = stat(path, &st);
      if (path_stat < 0) {
          if ((fp = fopen(path, "w+")) == NULL) {
-             perror(path);
              return -1;
          }
          fclose(fp);
@@ -632,7 +631,6 @@ char *spm_mkdtemp(const char *base, const char *name, const char *extended_path)
          if ((S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) > 0) {
              if (utime(path, NULL) < 0) {
                  // failed to set file time
-                 perror(path);
                  return -1;
              }
              // updated file time
diff --git a/lib/install.c b/lib/install.c
index c6e12ca..c5c2c4c 100644
--- a/lib/install.c
+++ b/lib/install.c
@@ -4,6 +4,37 @@
 #include <url.h>
 #include "spm.h"
 
+/**
+ * Check for the existence of `$ROOT/var/.spm_root`
+ * @param path
+ * @return yes=1, no=0
+ */
+int spm_hierarchy_is_root(SPM_Hierarchy *fs) {
+    if (exists(fs->rootrec) != 0) {
+        return 0;
+    }
+    return 1;
+}
+
+/**
+ * Initialize (not populate) a spm root directory.
+ * A "root record" is dropped into $ROOT/var
+ * @param fs `SPM_Hierarchy` structure
+ * @return success=0, error=-1
+ */
+int spm_hierarchy_make_root(SPM_Hierarchy *fs) {
+    // Create the root directory if it does not exist
+    if (mkdirs(fs->rootdir, 0755) != 0) {
+        return -1;
+    }
+
+    if (touch(fs->rootrec) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
 void spm_install_show_package(ManifestPackage *package) {
     if (package == NULL) {
         fprintf(stderr, "ERROR: package was NULL\n");
@@ -27,17 +58,6 @@ int spm_install(SPM_Hierarchy *fs, const char *tmpdir, const char *_package) {
         return -1;
     }
 
-    if (exists(fs->rootdir) != 0) {
-        if (SPM_GLOBAL.verbose) {
-            printf("Creating destination root: %s\n", fs->rootdir);
-        }
-        if (mkdirs(fs->rootdir, 0755) != 0) {
-            fprintf(SYSERROR);
-            free(package);
-            return -2;
-        }
-    }
-
     if (SPM_GLOBAL.verbose) {
         printf("Extracting archive: %s\n", package);
     }
@@ -192,6 +212,11 @@ int spm_do_install(SPM_Hierarchy *fs, ManifestList *mf, StrList *packages) {
         printf("Installation root: %s\n", fs->rootdir);
     }
 
+    if (spm_hierarchy_make_root(fs) < 0) {
+        spmerrno = SPM_ERR_ROOT_NO_RECORD;
+        return -1;
+    }
+
     // Produce a dependency tree from requested package(s)
     for (size_t i = 0; i < strlist_count(packages); i++) {
         char *item  = strlist_item(packages, i);
@@ -272,6 +297,12 @@ int spm_do_install(SPM_Hierarchy *fs, ManifestList *mf, StrList *packages) {
         manifest_free(tmp_manifest);
     }
 
+    if (spm_hierarchy_is_root(fs) == 0) {
+        if (SPM_GLOBAL.verbose) {
+            printf("Creating destination root: %s\n", fs->rootdir);
+        }
+    }
+
     printf("Installing package(s):\n");
     size_t num_installed = 0;
     for (size_t i = 0; requirements != NULL && requirements[i] != NULL; i++) {
@@ -288,7 +319,6 @@ int spm_do_install(SPM_Hierarchy *fs, ManifestList *mf, StrList *packages) {
 
         // Relocate installation root
         relocate_root(fs->rootdir, tmpdir);
-
         spm_install_package_record(fs, tmpdir, requirements[i]->name);
         num_installed++;
         free(package_path);
diff --git a/lib/purge.c b/lib/purge.c
index 997df51..da3e5e6 100644
--- a/lib/purge.c
+++ b/lib/purge.c
@@ -14,6 +14,7 @@ int spm_purge(SPM_Hierarchy *fs, const char *_package_name) {
     char *package_topdir = join((char *[]) {fs->dbrecdir, package_name, NULL}, DIRSEPS);
     char *descriptor = join((char *[]) {package_topdir, SPM_META_DESCRIPTOR, NULL}, DIRSEPS);
     char *filelist = join((char *[]) {package_topdir, SPM_META_FILELIST, NULL}, DIRSEPS);
+    char *rootrec = join((char *[]){path, "var", ".spm_root"}, DIRSEPS);
 
     if (spm_check_installed(fs, package_name) == 0) {
         // package is not installed in this root
@@ -67,6 +68,11 @@ int spm_purge(SPM_Hierarchy *fs, const char *_package_name) {
 int spm_do_purge(SPM_Hierarchy *fs, StrList *packages) {
     int status_remove = 0;
 
+    if (spm_hierarchy_is_root(fs) < 0) {
+        spmerrno = SPM_ERR_ROOT_NO_RECORD;
+        return -1;
+    }
+
     printf("Removing package(s):\n");
     for (size_t i = 0; i < strlist_count(packages); i++) {
         char *package = strlist_item(packages, i);
diff --git a/src/spm.c b/src/spm.c
index e2e7a8f..bb58401 100644
--- a/src/spm.c
+++ b/src/spm.c
@@ -128,6 +128,13 @@ int main(int argc, char *argv[], char *arge[]) {
                     usage(program_name);
                     exit(1);
                 }
+
+                // Installing into the system's root is forbidden for obvious reasons
+                if (strcmp(arg_next, DIRSEPS) == 0) {
+                    fprintf(stderr, "FATAL: refusing to operate on the system root directory\n");
+                    exit(1);
+                }
+
                 strcpy(rootdir, arg_next);
                 i++;
             }
@@ -236,7 +243,10 @@ int main(int argc, char *argv[], char *arge[]) {
     if (RUNTIME_INSTALL) {
         int status_install = 0;
         if ((status_install = spm_do_install(rootfs, mf, packages)) == -1) {
-            // failed to create temporary destination root
+            // general failure
+            if (spmerrno) {
+                spm_perror("Failed with reason");
+            }
             exit(1);
         } else if (status_install == -2) {
             // user said no when asked to proceed