Build preload lib to fake output of uname.

src/fake-environ/Makefile

@@ -0,0 +1,31 @@
+
+ifeq "$(CFLAGS)" ""
+  $(error CLFAGS not defined.)
+endif
+
+ifeq "$(TOOLS_DIR)" ""
+  $(error TOOLS_DIR not defined.)
+endif
+
+LIB = libpakfire_preload.so
+
+SOURCES = $(wildcard *.c)
+OBJECTS = $(patsubst %.c,%.o,$(SOURCES))
+
+.PHONY: all
+all: $(LIB)
+
+%.o: %.c Makefile
+	$(CC) $(CFLAGS) -o $@ -c $<
+
+$(LIB): $(OBJECTS)
+	$(CC) $(CFLAGS) -shared -o $@ $? -ldl
+
+.PHONY: install
+install: all
+	-mkdir -pv $(TOOLS_DIR)/lib/
+	install -p -m 755 $(LIB) $(TOOLS_DIR)/lib
+
+.PHONY: clean
+clean:
+	$(LIB)

src/fake-environ/uname.c

@@ -0,0 +1,50 @@
+
+
+#include <stdio.h>
+#include <string.h>
+#include <dlfcn.h>
+#include <stdlib.h>		/* for EXIT_FAILURE */
+#include <unistd.h>		/* for _exit() */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/syslog.h>
+#include <sys/utsname.h>
+
+#ifndef RTLD_NEXT
+#define RTLD_NEXT      ((void *) -1l)
+#endif
+
+typedef int (*uname_t)(struct utsname * buf);
+
+static void *get_libc_func(const char *funcname) {
+	char *error;
+
+	void *func = dlsym(RTLD_NEXT, funcname);
+	if ((error = dlerror()) != NULL) {
+		fprintf(stderr, "I can't locate libc function `%s' error: %s", funcname, error);
+		_exit(EXIT_FAILURE);
+	}
+
+	return func;
+}
+
+int uname(struct utsname *buf) {
+	char *env = NULL;
+
+	/* Call real uname to get the information we need. */
+	uname_t real_uname = (uname_t)get_libc_func("uname");
+	int ret = real_uname((struct utsname *) buf);
+
+	/* Replace release if requested. */
+	if ((env = getenv("UTS_RELEASE")) != NULL) {
+		strncpy(buf->release, env, _UTSNAME_RELEASE_LENGTH);
+	}
+
+	/* Replace machine type if requested. */
+	if ((env = getenv("UTS_MACHINE")) != NULL) {
+		strncpy(buf->machine, env, _UTSNAME_MACHINE_LENGTH);
+	}
+
+	return ret;
+}