testsuite: add trap to init_module() including simple test
diff --git a/testsuite/init_module.c b/testsuite/init_module.c
new file mode 100644
index 0000000..fd20c02
--- /dev/null
+++ b/testsuite/init_module.c
@@ -0,0 +1,169 @@
+#include <assert.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <dlfcn.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* kmod_elf_get_section() is not exported, we need the private header */
+#include <libkmod-private.h>
+
+/* FIXME: hack, change name so we don't clash */
+#undef ERR
+#include "testsuite.h"
+#include "stripped-module.h"
+
+struct mod {
+ struct mod *next;
+ int ret;
+ int errcode;
+ char name[];
+};
+
+static struct mod *modules;
+static bool need_init = true;
+
+static void parse_retcodes(struct mod *_modules, const char *s)
+{
+ const char *p;
+
+ if (s == NULL)
+ return;
+
+ for (p = s;;) {
+ struct mod *mod;
+ const char *modname;
+ char *end;
+ size_t modnamelen;
+ int ret, errcode;
+ long l;
+
+ modname = p;
+ if (modname == NULL || modname[0] == '\0')
+ break;
+
+ modnamelen = strcspn(s, ":");
+ if (modname[modnamelen] != ':')
+ break;
+
+ p = modname + modnamelen + 1;
+ if (p == NULL)
+ break;
+
+ l = strtol(p, &end, 0);
+ if (end == p || *end != ':')
+ break;
+ ret = (int) l;
+ p = end + 1;
+
+ l = strtol(p, &end, 0);
+ if (*end == ':')
+ p = end + 1;
+ else if (*end != '\0')
+ break;
+
+ errcode = (int) l;
+
+ mod = malloc(sizeof(*mod) + modnamelen + 1);
+ if (mod == NULL)
+ break;
+
+ memcpy(mod->name, modname, modnamelen);
+ mod->name[modnamelen] = '\0';
+ mod->ret = ret;
+ mod->errcode = errcode;
+ mod->next = _modules;
+ _modules = mod;
+ }
+}
+
+static struct mod *find_module(struct mod *_modules, const char *modname)
+{
+ struct mod *mod;
+
+ for (mod = _modules; mod != NULL; mod = mod->next) {
+ if (strcmp(mod->name, modname))
+ return mod;
+ }
+
+ return NULL;
+}
+
+static void init_retcodes(void)
+{
+ const char *s;
+
+ if (!need_init)
+ return;
+
+ need_init = false;
+ s = getenv(S_TC_INIT_MODULE_RETCODES);
+ if (s == NULL) {
+ fprintf(stderr, "TRAP init_module(): missing export %s?\n",
+ S_TC_INIT_MODULE_RETCODES);
+ }
+
+ parse_retcodes(modules, s);
+}
+
+TS_EXPORT long init_module(void *mem, unsigned long len, const char *args);
+
+/*
+ * FIXME: change /sys/module/<modname> to fake-insert a module
+ *
+ * Default behavior is to exit successfully. If this is not the intended
+ * behavior, set TESTSUITE_INIT_MODULE_RETCODES env var.
+ */
+long init_module(void *mem, unsigned long len, const char *args)
+{
+ const char *modname;
+ struct kmod_elf *elf;
+ struct mod *mod;
+ const void *buf;
+ uint64_t bufsize;
+ int err;
+
+ init_retcodes();
+
+ elf = kmod_elf_new(mem, len);
+ if (elf == NULL)
+ return 0;
+
+ err = kmod_elf_get_section(elf, ".gnu.linkonce.this_module", &buf,
+ &bufsize);
+ kmod_elf_unref(elf);
+
+ /*
+ * We couldn't find the module's name inside the ELF file. Just exit
+ * as if it was successful
+ */
+ if (err < 0)
+ return 0;
+
+ modname = (char *)buf + offsetof(struct module, name);
+ mod = find_module(modules, modname);
+ if (mod == NULL)
+ return 0;
+
+ errno = mod->errcode;
+ return mod->ret;
+}
+
+/* the test is going away anyway, but lets keep valgrind happy */
+void free_resources(void) __attribute__((destructor));
+void free_resources(void)
+{
+ while (modules) {
+ struct mod *mod = modules->next;
+ free(modules);
+ modules = mod;
+ }
+}