dynamic-dso/dynso_internal.h

#ifndef DYNSO_INTERNAL_H_
#define DYNSO_INTERNAL_H_

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

#include <elf.h>
#include <link.h>

#include <sys/auxv.h>
#include <sys/stat.h>

// glibc stuff...

struct link_map_priv1 {
	// SVR4
	ElfW(Addr) l_addr;
	char* l_name;
	ElfW(Dyn)* l_ld;
	struct link_map_priv1* l_next, *l_prev;

	// glibc-specific
	struct link_map_priv1* l_real;
	Lmid_t l_ns;
	struct libname_list* l_libname;
	ElfW(Dyn)* l_info[];
};

struct libname_list;
struct r_found_version;
struct r_search_path_elem;
struct r_file_id {
	dev_t dev;
	ino64_t ino;
};
struct r_scope_elem {
	struct link_map_priv1** r_list;
	unsigned int r_nlist;
};
struct r_search_path_struct {
	struct r_search_path_elem** dirs;
	int malloced;
};
struct link_map_priv2 {
	const ElfW(Phdr)* l_phdr;
	ElfW(Addr) l_entry;
	ElfW(Half) l_phnum;
	ElfW(Half) l_ldnum;

	struct r_scope_elem l_searchlist, l_symbolic_searchlist;

	struct link_map* l_loader;

	struct r_found_version* l_versions;
	unsigned int l_nversions;

	Elf_Symndx l_nbuckets;
	Elf32_Word l_gnu_bitmask_idxbits;
	Elf32_Word l_gnu_shift;
	const ElfW(Addr)* l_gnu_bitmask;
	union {
		const Elf32_Word* l_gnu_buckets;
		const Elf_Symndx* l_chain;
	};
	union {
		const Elf32_Word* l_gnu_chain_zero;
		const Elf_Symndx* l_buckets;
	};

	unsigned int l_direct_opencount;
	enum {
		lt_executable,
		lt_library,
		lt_loaded
	} l_type : 2;
	unsigned int l_relocated : 1;
	unsigned int l_init_called : 1;
	unsigned int l_global : 1;
	unsigned int l_reserved : 2;
	unsigned int l_phdr_allocated : 1;
	unsigned int l_soname_added : 1;
	unsigned int l_faked : 1;
	unsigned int l_need_tls_init : 1;
	unsigned int l_auditing : 1;
	unsigned int l_audit_any_plt : 1;
	unsigned int l_removed : 1;
	unsigned int l_contiguous : 1;
	unsigned int l_symbolic_in_local_scope : 1;
	unsigned int l_free_initfini : 1;

	//bool l_nodelete_active, l_nodelete_pending; // FIXME
	// ^ these two are added somewhere between glibc 2.30 (the one on my
	//   system) and now (current master), I should probably add a priv3 thing
	//   to accomodate for this, but EFFORT

/*#if defined(__i386__) || defined(__x86_64__)
	enum {
		lc_unknown = 0,
		lc_none = 1<<0,
		lc_ibt = 1<<1,
		lc_shstk = 1<<2,
		lc_ibt_and_shstk = lc_ibt | lc_shstk
	} l_cet : 3;
#endif*/
};

struct link_map_priv3 {
	struct r_search_path_struct l_rpath_dirs;

	struct reloc_result {
		ElfW(Addr) addr;
		struct link_map_priv1* bound;
		unsigned int boundndx;
		uint32_t enterexit;
		unsigned int flags;
		unsigned int init;
	} *l_reloc_result;

	ElfW(Versym)* l_versyms;
	const char* l_origin;
	ElfW(Addr) l_map_start, l_map_end;
	ElfW(Addr) l_text_end;
	struct r_scope_elem* l_scope_mem[4];
	size_t l_scope_max;
	struct r_scope_elem** l_scope;
	struct r_scope_elem* l_local_scope[2];
	struct r_file_id l_file_id;
	struct r_search_path_struct l_runpath_dirs;
	struct link_map** l_initfini;
	struct link_map_reldeps {
		unsigned int act;
		struct link_map* list[];
	} *l_reldeps;
	unsigned int l_reldepsmax;

	unsigned int l_used;
	ElfW(Word) l_feature_1, l_flags_1, l_flags;
	int l_idx;

	// more stuff...
};

typedef struct link_map_priv1* (*dl_new_object_f)(char* realname, const char* libname,
		int type, struct link_map* loader, int mode, Lmid_t nsid);

typedef void (*dl_add_to_namespace_list_f)(struct link_map_priv1 *new, Lmid_t nsid);

typedef void (*dl_setup_hash_f)(struct link_map_priv1* map);

// actual stuff internal for this lib now

struct rtldinfo {
	ElfW(Addr) base;
	ElfW(Sym)* symtab;
	char* strtab;
	size_t strsz;
	size_t shsz;
	ptrdiff_t syment;
	bool sym_malloc, str_malloc;
};

struct inject_undo_info {
	struct r_scope_elem** dest;
	struct r_scope_elem* old;
	struct r_scope_elem* alloced;
	//struct link_map_priv1** rlist;
};

struct dynso_sym {
	const char* name;
	void* value;
	size_t size;
	int type;
};
struct dynso_lib {
	struct inject_undo_info undoinf;
	dl_new_object_f _dl_new_object;
	dl_add_to_namespace_list_f _dl_add_to_namespace_list;
	dl_setup_hash_f _dl_setup_hash;
	ElfW(Dyn)* dyn;
	ElfW(Sym)* sym;
	Elf_Symndx* idx;
	char* str;
	struct link_map_priv1* caller;
	struct link_map_priv1* fake1;
	struct link_map_priv2* fake2;
	struct link_map_priv3* fake3;
	struct dynso_sym* syms;
	size_t address;
	size_t nsyms;
	size_t syms_cap;
	Lmid_t ns;
	bool added;
	bool removed;
	bool alloc_syms;
};
//extern void _start(void) __attribute__((__noreturn__));

static ptrdiff_t get_priv1_priv2_offset(void);
static ptrdiff_t get_priv2_priv3_offset(void);

static struct link_map_priv2* priv1_to_priv2(struct link_map_priv1* lm);
static struct link_map_priv3* priv2_to_priv3(struct link_map_priv2* l2);
inline static struct link_map_priv3* priv1_to_priv3(struct link_map_priv1* lm) {
	return priv2_to_priv3(priv1_to_priv2(lm));
}

static enum dynso_err get_rtld_symtab(struct rtldinfo* inf);
static enum dynso_err link_private_rtld_syms(struct dynso_lib* l);

static enum dynso_err inject_in_scope_of(struct inject_undo_info* r,
		struct link_map_priv3* victim, struct link_map_priv1* add);
static void inject_undo(const struct inject_undo_info* inf);

#endif