initial commit -- v1 code

src/module.cpp

@@ -0,0 +1,119 @@
+#include "module.h"
+
+#include "dbg.h"
+#include "filesystem.h"
+#include "strtools.h"
+
+#include <elf.h>
+#include <fcntl.h>
+#include <link.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+namespace modules
+{
+	CModule* engine = nullptr;
+	CModule* server = nullptr;
+	CModule* schemasystem = nullptr;
+}
+
+static bool GetModuleInformation(void* handle, void** base, size_t* length, std::vector<Section>& sections)
+{
+	link_map* lmap = nullptr;
+	if (dlinfo(handle, RTLD_DI_LINKMAP, &lmap) != 0 || !lmap)
+		return false;
+
+	int fd = open(lmap->l_name, O_RDONLY);
+	if (fd == -1)
+		return false;
+
+	struct stat st {};
+	if (fstat(fd, &st) != 0)
+	{
+		close(fd);
+		return false;
+	}
+
+	void* map = mmap(nullptr, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (map == MAP_FAILED)
+		return false;
+
+	auto* ehdr = static_cast<ElfW(Ehdr)*>(map);
+	auto* shdrs = reinterpret_cast<ElfW(Shdr)*>(reinterpret_cast<uintptr_t>(ehdr) + ehdr->e_shoff);
+	const char* strTab = reinterpret_cast<const char*>(reinterpret_cast<uintptr_t>(ehdr) + shdrs[ehdr->e_shstrndx].sh_offset);
+
+	for (int i = 0; i < ehdr->e_phnum; ++i)
+	{
+		auto* phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<uintptr_t>(ehdr) + ehdr->e_phoff + i * ehdr->e_phentsize);
+		if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X))
+		{
+			*base = reinterpret_cast<void*>(lmap->l_addr + phdr->p_vaddr);
+			*length = phdr->p_filesz;
+			break;
+		}
+	}
+
+	for (int i = 0; i < ehdr->e_shnum; ++i)
+	{
+		auto* shdr = reinterpret_cast<ElfW(Shdr)*>(reinterpret_cast<uintptr_t>(shdrs) + i * ehdr->e_shentsize);
+		if (*(strTab + shdr->sh_name) == '\0')
+			continue;
+		sections.push_back({strTab + shdr->sh_name, reinterpret_cast<void*>(lmap->l_addr + shdr->sh_addr), shdr->sh_size});
+	}
+
+	munmap(map, st.st_size);
+	return *base && *length;
+}
+
+CModule::CModule(const char* relativePath, const char* module) : m_name(module)
+{
+	char path[MAX_PATH];
+	V_snprintf(path, sizeof(path), "%s%s%s%s%s", Plat_GetGameDirectory(), relativePath, MODULE_PREFIX, module, MODULE_EXT);
+
+	m_handle = dlopen(path, RTLD_NOW | RTLD_NOLOAD);
+	if (!m_handle)
+		m_handle = dlopen(path, RTLD_NOW);
+	if (!m_handle)
+		Error("[SendProxy] Could not open %s: %s\n", path, dlerror());
+
+	if (!GetModuleInformation(m_handle, &m_base, &m_size, m_sections))
+		Error("[SendProxy] Could not inspect %s\n", path);
+
+	SPMessage("module %s base=%p size=%zu\n", module, m_base, m_size);
+}
+
+void* CModule::FindSignature(const uint8_t* pattern, size_t length, int& error) const
+{
+	error = SIG_NOT_FOUND;
+	void* found = nullptr;
+	auto* memory = static_cast<uint8_t*>(m_base);
+
+	for (size_t i = 0; i + length < m_size; ++i)
+	{
+		size_t matched = 0;
+		while (matched < length && (pattern[matched] == 0x2A || memory[i + matched] == pattern[matched]))
+			++matched;
+		if (matched != length)
+			continue;
+		if (found)
+		{
+			error = SIG_FOUND_MULTIPLE;
+			return found;
+		}
+		found = memory + i;
+		error = SIG_OK;
+	}
+
+	return found;
+}
+
+void* CModule::FindInterface(const char* name) const
+{
+	auto fn = reinterpret_cast<CreateInterfaceFn>(dlsym(m_handle, "CreateInterface"));
+	if (!fn)
+		return nullptr;
+	return fn(name, nullptr);
+}
+