From 2bc5861dc035a1f753e8f017d005319a0f6fc193 Mon Sep 17 00:00:00 2001
From: Nathan Fisher <nfisher.sr@gmail.com>
Date: Thu, 21 Sep 2023 22:58:32 -0400
Subject: [PATCH] Wrote the `extract_node` functionality; TODO: test it;

---
 haggis.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 84 insertions(+), 14 deletions(-)

diff --git a/haggis.c b/haggis.c
index d6d893c..fee190a 100644
--- a/haggis.c
+++ b/haggis.c
@@ -32,11 +32,14 @@
 
 #include "haggis.h"
 #include "mq.h"
+#include <asm-generic/errno-base.h>
 #include <assert.h>
 #include <errno.h>
+#include <libgen.h>
 #include <limits.h>          // PATH_MAX
+#include <linux/limits.h>
+#include <stddef.h>
 #include <stdint.h>          // uint<x>_t
-#include <sys/syslimits.h>
 #include <sys/unistd.h>
 
 #if defined(__FreeBSD__) || defined(__DragonFly__)
@@ -714,14 +717,16 @@ int haggis_extract_dev(haggis_node *node, char *basedir) {
     dev_t   dev;
     mode_t  mode;
     char   *path;
-    int     ret;
+    int     ret, major, minor;
 
     assert(geteuid() == 0);
     assert(node->filetype.tag == block || node->filetype.tag == character);
     path = get_full_path(&node->name, basedir);
     if (path == NULL)
         return errno;
-    dev = makedev((int)node->filetype.f_type.dev.major.val, (int)node->filetype.f_type.dev.minor.val);
+    major = (int)node->filetype.f_type.dev.major.val;
+    minor = (int)node->filetype.f_type.dev.minor.val;
+    dev = makedev(major, minor);
     mode = (mode_t)node->mode.val;
     ret = mknod(path, mode, dev);
     free(path);
@@ -746,14 +751,15 @@ int haggis_extract_fifo(haggis_node *node, char *basedir) {
 }
 
 int haggis_extract_symlink(haggis_node *node, char *basedir) {
-    char *path;
+    char *path, *target;
     int   ret;
 
     assert(node->filetype.tag == softlink);
     path = get_full_path(&node->name, basedir);
     if (path == NULL)
         return 1;
-    ret = symlink(node->filetype.f_type.target.name, path);
+    target = node->filetype.f_type.target.name;
+    ret = symlink(target, path);
     free(path);
     if (ret != 0)
         return errno;
@@ -791,39 +797,103 @@ int haggis_extract_hardlink(haggis_node *node, char *basedir) {
     return 0;
 }
 
+int mkdir_p(char *dir) {
+    struct stat st;
+
+    if (!stat(dir, &st))
+        return 0;
+
+    if (mkdir_p(dirname(strndup(dir, PATH_MAX))))
+        return 1;
+    return mkdir(dir, 0755);
+}
+
 int haggis_extract_dir(haggis_node *node, char *basedir) {
-    // todo
+    char *path;
+
     assert(node->filetype.tag == directory);
+    path = get_full_path(&node->name, basedir);
+    if (mkdir_p(path)) {
+        free(path);
+        return errno;
+    }
+    free(path);
     return 0;
 }
 
 int haggis_extract_file(haggis_node *node, char *basedir) {
-    // todo
+    char   *path;
+    FILE   *fd;
+    size_t  len;
+    int ret;
+
     assert(node->filetype.tag == normal);
+    path = get_full_path(&node->name, basedir);
+    if (path == NULL) {
+        return 1;
+    }
+    if (mkdir_p(dirname(strndup(path, PATH_MAX)))) {
+        free(path);
+        return errno;
+    }
+    fd = fopen(path, "w");
+    if (fd == NULL) {
+        free(path);
+        return 1;
+    }
+    len = (size_t)node->filetype.f_type.file.len.val;
+    ret = fwrite(node->filetype.f_type.file.data, len, 1, fd);
+    if (ret != len) {
+        return 2;
+    }
+    free(path);
     return 0;
 }
 
 int haggis_extract_node(FILE *stream, char *basedir, haggis_node *node) {
-    // todo
+    // todo: take a `haggis_mq` pointer as a parameter
+    char *path, *dir;
+    int   ret;
+
+    path = get_full_path(&node->name, basedir);
+    dir = dirname(strndup(path, PATH_MAX));
+    mkdir_p(dir);
     switch (node->filetype.tag) {
     case block:
     case character:
         if (geteuid() == 0)
-            return haggis_extract_dev(node, basedir);
+            ret = haggis_extract_dev(node, basedir);
+        // todo: Add message type for skipped file and add it to queue if we're
+        // not root when calling this. We want this to be a warning, but not a
+        // fatal error.
+        break;
     case fifo:
-        return haggis_extract_fifo(node, basedir);
+        ret = haggis_extract_fifo(node, basedir);
+        break;
     case softlink:
         return haggis_extract_symlink(node, basedir);
     case hardlink:
-        return haggis_extract_hardlink(node, basedir);
+        ret = haggis_extract_hardlink(node, basedir);
+        break;
     case directory:
-        return haggis_extract_dir(node, basedir);
+        ret = haggis_extract_dir(node, basedir);
+        break;
     case normal:
-        return haggis_extract_file(node, basedir);
+        ret = haggis_extract_file(node, basedir);
+        break;
     case eof:
         return 0;
     }
-    return 0;
+    if (geteuid() == 0) {
+        ret = chown(path, (uid_t)node->uid.val, (gid_t)node->gid.val);
+        if (ret != 0) {
+            free(path);
+            return errno;
+        }
+    }
+    ret = chmod(path, (mode_t)node->mode.val);
+    // todo: make a 'NodeCreated' message and add it to the message queue
+    return ret;
 }
 
 int haggis_load_node(FILE *stream, haggis_node *node) {