enumerate over installed Debian/Ubuntu packages

src/libimcv/os_info/os_info.c

@@ -17,6 +17,7 @@
 
 #include <sys/utsname.h>
 #include <stdio.h>
+#include <stdarg.h>
 
 #include <collections/linked_list.h>
 #include <utils/debug.h>
@@ -182,12 +183,94 @@ METHOD(os_info_t, get_setting, chunk_t,
 	return chunk_clone(value);
 }
 
+typedef struct {
+	/**
+	 * implements enumerator_t 
+	 */
+	enumerator_t public;
+
+	/**
+	 * streamed pipe
+	 */
+	FILE* file;
+
+	/**
+	 * line buffer
+	 */
+	char line[512];
+
+} package_enumerator_t;
+
+/**
+ * Implementation of package_enumerator.destroy.
+ */
+static void package_enumerator_destroy(package_enumerator_t *this)
+{
+	pclose(this->file);
+	free(this);
+}
+
+/**
+ * Implementation of package_enumerator.enumerate
+ */
+static bool package_enumerator_enumerate(package_enumerator_t *this, ...)
+{
+	chunk_t *name, *version;
+	char *pos;
+	va_list args;
+
+	if (!fgets(this->line, sizeof(this->line), this->file))
+	{
+		return FALSE;
+	}
+	va_start(args, this);
+
+	name = va_arg(args, chunk_t*);
+	name->ptr = this->line;
+	pos = strchr(this->line, '\t');
+	if (!pos)
+	{
+		return FALSE;
+	}
+	name->len = pos++ - this->line;
+
+	version = va_arg(args, chunk_t*);
+	version->ptr = pos;
+	version->len = strlen(pos) - 1;
+
+	va_end(args);
+	return TRUE;
+}
+
 METHOD(os_info_t, create_package_enumerator, enumerator_t*,
 	private_os_info_t *this)
 {
-	/* TODO */
+	FILE *file;
+	package_enumerator_t *enumerator;
+	chunk_t debian = { "Debian", 6 };
+	chunk_t ubuntu = { "Ubuntu", 6 };
 
-	return NULL;
+	/* Only Debian and Ubuntu package enumeration is currently supported */
+	if (!chunk_equals(this->name, debian) && !chunk_equals(this->name, ubuntu))
+	{
+		return NULL;
+	}
+
+	/* Open a pipe stream for reading the output of the dpkg-query commmand */
+	file = popen("/usr/bin/dpkg-query --show", "r");
+	if (!file)
+	{
+		DBG1(DBG_IMC, "failed to run dpkg command");
+		return NULL;
+	}
+
+	/* Create a package enumerator instance */
+	enumerator = malloc_thing(package_enumerator_t);
+	enumerator->public.enumerate = (void*)package_enumerator_enumerate;
+	enumerator->public.destroy = (void*)package_enumerator_destroy;
+	enumerator->file = file;
+
+	return (enumerator_t*)enumerator;
 }