From: Michael Tremer <michael.tremer@ipfire.org>
Date: Fri, 3 Jan 2025 08:52:14 +0000 (+0000)
Subject: ELF: Add a function to fetch the interpreter
X-Git-Tag: 0.9.30~569
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=309450602dd25ec8c6a8f020e6035f687f12166b;p=pakfire.git

ELF: Add a function to fetch the interpreter

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/pakfire/elf.c b/src/pakfire/elf.c
index c6c681fab..d6863d2e7 100644
--- a/src/pakfire/elf.c
+++ b/src/pakfire/elf.c
@@ -55,6 +55,9 @@ struct pakfire_elf {
 	// Strings
 	size_t shstrndx;
 
+	// Interpreter
+	const char* interpreter;
+
 	// GNU Build ID
 	char* build_id;
 
@@ -421,6 +424,42 @@ static int pakfire_elf_dyn_walk(struct pakfire_elf* self,
 	return 0;
 }
 
+static int pakfire_elf_fetch_interpreter(
+		struct pakfire_elf* self, const GElf_Phdr* phdr, void* data) {
+	Elf_Data* chunk = NULL;
+
+	switch (phdr->p_type) {
+		case PT_INTERP:
+			chunk = elf_getdata_rawchunk(self->elf, phdr->p_offset, phdr->p_filesz, ELF_T_BYTE);
+			if (!chunk || !chunk->d_buf) {
+				ERROR(self->ctx, "Failed to fetch the interpreter\n");
+				return -EINVAL;
+			}
+
+			// Store the interpreter
+			self->interpreter = (const char*)chunk->d_buf;
+			break;
+
+		default:
+			break;
+	}
+
+	return 0;
+}
+
+const char* pakfire_elf_interpreter(struct pakfire_elf* self) {
+	int r;
+
+	// Fetch the interpreter if not available
+	if (!self->interpreter) {
+		r = pakfire_elf_foreach_program_header(self, pakfire_elf_fetch_interpreter, NULL);
+		if (r < 0)
+			return NULL;
+	}
+
+	return self->interpreter;
+}
+
 int pakfire_elf_is_pie(struct pakfire_elf* self) {
 	switch (pakfire_elf_type(self)) {
 		// Shared Object files are good
diff --git a/src/pakfire/elf.h b/src/pakfire/elf.h
index f723d5224..a1d591797 100644
--- a/src/pakfire/elf.h
+++ b/src/pakfire/elf.h
@@ -43,6 +43,7 @@ int pakfire_elf_machine(struct pakfire_elf* self);
 int pakfire_elf_endianess(struct pakfire_elf* self);
 const char* pakfire_elf_build_id(struct pakfire_elf* self);
 const char* pakfire_elf_debuglink(struct pakfire_elf* self);
+const char* pakfire_elf_interpreter(struct pakfire_elf* elf);
 
 int pakfire_elf_is_pie(struct pakfire_elf* self);
 int pakfire_elf_has_ssp(struct pakfire_elf* self);