initrd-put: Split code for greater maintainability

Signed-off-by: Alexey Gladkov <[email protected]>

utils/initrd-put/Makefile.mk

@@ -2,7 +2,14 @@
 
 ifeq ($(HAVE_LIBELF),yes)
 initrd_put_DEST = $(dest_bindir)/initrd-put
-initrd_put_SRCS = $(utils_srcdir)/initrd-put/initrd-put.c
+initrd_put_SRCS = \
+	$(utils_srcdir)/initrd-put/memory.c \
+	$(utils_srcdir)/initrd-put/queue.c \
+	$(utils_srcdir)/initrd-put/tree.c \
+	$(utils_srcdir)/initrd-put/enqueue-library.c \
+	$(utils_srcdir)/initrd-put/enqueue-shebang.c \
+	$(utils_srcdir)/initrd-put/initrd-put.c
+
 initrd_put_LIBS = $(HAVE_LIBELF_LIBS) $(HAVE_LIBJSON_C_LIBS)
 initrd_put_CFLAGS = $(HAVE_LIBELF_CFLAGS) $(HAVE_LIBJSON_C_CFLAGS) \
 		    -I$(utils_srcdir)/initrd-put \

utils/initrd-put/elf_dlopen.c

@@ -15,6 +15,7 @@
 #include <json-c/json_visit.h>
 
 #include "config.h"
+#include "memory.h"
 #include "elf_dlopen.h"
 
 extern int verbose;
@@ -217,9 +218,7 @@ static int visit_userfunc(json_object *jso, int flags, json_object *,
 		    in_envvar("IGNORE_PUT_DLOPEN_PRIORITY", elf_metadata.priority))
 			return JSON_C_VISIT_RETURN_SKIP;
 
-		soname = calloc(array_len, sizeof(char *));
-		if (!soname)
-			err(EXIT_FAILURE, "calloc");
+		soname = xcalloc(array_len, sizeof(char *));
 
 		for (i = 0; i < array_len; i++) {
 			json_object *child = json_object_array_get_idx(value, i);

utils/initrd-put/enqueue-library.c

@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#define _GNU_SOURCE
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <ctype.h>
+#include <err.h>
+
+#include <gelf.h>
+
+#include "queue.h"
+#include "tree.h"
+#include "enqueue.h"
+#include "elf_dlopen.h"
+
+#define _FDO_ELF_METADATA 0x407c0c0a
+
+extern int verbose;
+
+static bool is_dynamic_elf_file(const char *filename, int fd) __attribute__((__nonnull__ (1)));
+static int enqueue_elf_dlopen(const char *filename, int fd) __attribute__((__nonnull__ (1)));
+static int enqueue_shared_libraries(const char *filename) __attribute__((__nonnull__ (1)));
+
+
+bool is_dynamic_elf_file(const char *filename, int fd)
+{
+	bool is_dynamic = false;
+	Elf *e;
+	Elf_Scn *scn;
+	size_t shstrndx;
+
+	if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
+		warnx("%s: elf_begin: %s", filename, elf_errmsg(-1));
+		goto err;
+	}
+
+	switch (elf_kind(e)) {
+		case  ELF_K_NONE:
+		case  ELF_K_AR:
+		case ELF_K_COFF:
+		case  ELF_K_ELF:
+			break;
+		default:
+			goto end;
+	}
+
+	if (elf_getshdrstrndx(e, &shstrndx) != 0) {
+		warnx("%s: elf_getshdrstrndx: %s", filename, elf_errmsg(-1));
+		goto end;
+	}
+
+	for (scn = NULL; (scn = elf_nextscn(e, scn)) != NULL;) {
+		GElf_Shdr  shdr;
+
+		if (gelf_getshdr(scn, &shdr) != &shdr) {
+			warnx("%s: gelf_getshdr: %s", filename, elf_errmsg(-1));
+			goto end;
+		}
+
+		if (shdr.sh_type == SHT_DYNAMIC) {
+			is_dynamic = true;
+			break;
+		}
+	}
+end:
+	elf_end(e);
+err:
+	return is_dynamic;
+}
+
+int enqueue_elf_dlopen(const char *filename, int fd)
+{
+	int ret = 0;
+	char library[PATH_MAX + 1];
+	Elf *e;
+	Elf_Scn *scn;
+
+	if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
+		warnx("%s: elf_begin: %s", filename, elf_errmsg(-1));
+		goto err;
+	}
+
+	switch (elf_kind(e)) {
+		case  ELF_K_NONE:
+		case  ELF_K_AR:
+		case ELF_K_COFF:
+		case  ELF_K_ELF:
+			break;
+		default:
+			goto end;
+	}
+
+	for (scn = NULL; (scn = elf_nextscn(e, scn)) != NULL;) {
+		GElf_Shdr  shdr;
+		GElf_Nhdr nhdr;
+		size_t off, next, n_off, d_off;
+		Elf_Data *data;
+
+		if (gelf_getshdr(scn, &shdr) != &shdr) {
+			warnx("%s: gelf_getshdr: %s", filename, elf_errmsg(-1));
+			goto end;
+		}
+
+		if (shdr.sh_type != SHT_NOTE)
+			continue;
+
+		data = elf_getdata(scn, NULL);
+		if (data == NULL) {
+			warnx("%s: elf_getdata: %s", filename, elf_errmsg(-1));
+			goto end;
+		}
+
+		off = 0;
+		while ((next = gelf_getnote(data, off, &nhdr, &n_off, &d_off)) > 0) {
+			if (nhdr.n_type == _FDO_ELF_METADATA && nhdr.n_namesz == sizeof(ELF_NOTE_FDO) && !strcmp(data->d_buf + n_off, ELF_NOTE_FDO)) {
+				library[0] = '\0';
+
+				process_json_metadata(filename, (char *)data->d_buf + d_off, library);
+
+				if (library[0] == '/' && !is_path_added(library))
+					enqueue_item(library, -1);
+			}
+			off = next;
+		}
+	}
+end:
+	elf_end(e);
+err:
+	return ret;
+}
+
+int enqueue_shared_libraries(const char *filename)
+{
+	FILE *pfd;
+	char *line = NULL;
+	size_t len = 0;
+	ssize_t n;
+	char command[PATH_MAX + 10];
+
+	snprintf(command, sizeof(command), "ldd %s 2>&1", filename);
+
+	pfd = popen(command, "r");
+	if (!pfd) {
+		warn("popen(ldd): %s", filename);
+		return -1;
+	}
+
+	while ((n = getline(&line, &len, pfd)) != -1) {
+		char *p;
+
+		if (line[n - 1] == '\n')
+			line[n - 1] = '\0';
+
+		p = strstr(line, "(0x");
+		if (!p)
+			continue;
+		*p-- = '\0';
+
+		while (line != p && isspace(*p))
+			*p-- = '\0';
+
+		p = strstr(line, " => ");
+		if (p)
+			p += 4;
+		else
+			p = line;
+
+		while (*p != '\0' && isspace(*p))
+			*p++ = '\0';
+
+		if (*p != '/')
+			continue;
+
+		if (verbose > 1)
+			warnx("shared object '%s' depends on '%s'", filename, p);
+
+		if (is_path_added(p))
+			continue;
+
+		enqueue_item(p, -1);
+	}
+
+	free(line);
+	pclose(pfd);
+
+	return 0;
+}
+
+void init_elf_library(void)
+{
+	if (elf_version(EV_CURRENT) == EV_NONE)
+		errx(EXIT_FAILURE, "ELF library initialization failed: %s", elf_errmsg(-1));
+}
+
+bool is_elf_file(char buf[LINE_MAX])
+{
+	return (buf[0] == ELFMAG[0] &&
+	        buf[1] == ELFMAG[1] &&
+	        buf[2] == ELFMAG[2] &&
+	        buf[3] == ELFMAG[3]);
+}
+
+int enqueue_libraries(const char *filename, int fd)
+{
+	int ret = 0;
+
+	if (is_dynamic_elf_file(filename, fd)) {
+		ret = enqueue_shared_libraries(filename);
+		if (!ret)
+			ret = enqueue_elf_dlopen(filename, fd);
+	}
+	return ret;
+}

utils/initrd-put/enqueue-shebang.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <ctype.h>
+#include <err.h>
+
+#include "tree.h"
+#include "queue.h"
+#include "enqueue.h"
+
+extern int verbose;
+
+bool is_shebang(char buf[LINE_MAX])
+{
+	return (buf[0] == '#' &&
+	        buf[1] == '!');
+}
+
+int enqueue_shebang(const char *filename, char buf[LINE_MAX])
+{
+	char *p, *q;
+
+	for (p = &buf[2]; *p && isspace(*p); p++);
+	for (q = p; *q && (!isspace(*q)); q++);
+	*q = '\0';
+
+	if (verbose > 1)
+		warnx("shell script '%s' uses the '%s' interpreter", filename, p);
+
+	if (!is_path_added(p))
+		enqueue_item(p, -1);
+
+	return 0;
+}

utils/initrd-put/enqueue.h

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#ifndef __INITRD_PUT_ENQUEUE_H__
+#define __INITRD_PUT_ENQUEUE_H__
+
+#include <stdbool.h>
+#include <limits.h>
+
+bool is_shebang(char buf[LINE_MAX]);
+int enqueue_shebang(const char *filename, char buf[LINE_MAX]);
+
+void init_elf_library(void);
+bool is_elf_file(char buf[LINE_MAX]);
+int enqueue_libraries(const char *filename, int fd);
+
+#endif // __INITRD_PUT_ENQUEUE_H__
+