Initial commit of some stuff written so far. Still in state of flux. Expect

breakage and major changes.

1 files changed, 349 insertions, 0 deletions

diff --git a/src/archive.c b/src/archive.c
new file mode 100644
index 0000000..e5092dc
--- /dev/null
+++ b/src/archive.c
@@ -0,0 +1,349 @@
+/* archive.c - Alpine Package Keeper (APK)
+ *
+ * Copyright (C) 2005-2008 Natanael Copa <n@tanael.org>
+ * Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation. See http://www.gnu.org/ for details.
+ */
+
+#include <stdio.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <malloc.h>
+#include <string.h>
+#include <unistd.h>
+#include <sysexits.h>
+#include <sys/wait.h>
+
+#include "apk_defines.h"
+#include "apk_archive.h"
+
+#ifndef GUNZIP_BINARY
+#define GUNZIP_BINARY "/bin/gunzip"
+#endif
+
+struct tar_header {
+	/* ustar header, Posix 1003.1 */
+	char name[100];     /*   0-99 */
+	char mode[8];       /* 100-107 */
+	char uid[8];        /* 108-115 */
+	char gid[8];        /* 116-123 */
+	char size[12];      /* 124-135 */
+	char mtime[12];     /* 136-147 */
+	char chksum[8];     /* 148-155 */
+	char typeflag;      /* 156-156 */
+	char linkname[100]; /* 157-256 */
+	char magic[8];      /* 257-264 */
+	char uname[32];     /* 265-296 */
+	char gname[32];     /* 297-328 */
+	char devmajor[8];   /* 329-336 */
+	char devminor[8];   /* 337-344 */
+	char prefix[155];   /* 345-499 */
+	char padding[12];   /* 500-512 */
+};
+
+static int get_dev_null(void)
+{
+	static int fd_null = 0;
+
+	if (fd_null == 0) {
+		fd_null = open("/dev/null", O_WRONLY);
+		if (fd_null < 0)
+			err(EX_OSFILE, "/dev/null");
+	}
+	return fd_null;
+
+}
+
+pid_t apk_open_gz(int *fd)
+{
+	int pipe_fd[2];
+	pid_t child_pid;
+
+	if (pipe(pipe_fd) < 0)
+		err(EX_OSERR, "pipe");
+
+	child_pid = fork();
+	if (child_pid < 0)
+		err(EX_OSERR, "fork");
+
+	if (child_pid == 0) {
+		close(pipe_fd[0]);
+		dup2(pipe_fd[1], STDOUT_FILENO);
+		dup2(*fd, STDIN_FILENO);
+		dup2(get_dev_null(), STDERR_FILENO);
+		close(pipe_fd[1]);
+		execl(GUNZIP_BINARY, "gunzip", "-c", NULL);
+		err(EX_UNAVAILABLE, GUNZIP_BINARY);
+	}
+
+	close(pipe_fd[1]);
+	*fd = pipe_fd[0];
+
+	return child_pid;
+}
+
+#define GET_OCTAL(s) apk_blob_uint(APK_BLOB_PTR_LEN(s, sizeof(s)), 8)
+
+static int do_splice(int from_fd, int to_fd, int len)
+{
+	int i = 0, r;
+
+	while (i != len) {
+		r = splice(from_fd, NULL, to_fd, NULL, len - i, SPLICE_F_MOVE);
+		if (r == -1)
+			return i;
+		i += r;
+	}
+
+	return i;
+}
+
+int apk_parse_tar(int fd, apk_archive_entry_parser parser, void *ctx)
+{
+	struct apk_archive_entry entry;
+	struct tar_header buf;
+	unsigned long offset = 0;
+	int end = 0, r;
+
+	memset(&entry, 0, sizeof(entry));
+	while (read(fd, &buf, 512) == 512) {
+		offset += 512;
+		if (buf.name[0] == '\0') {
+			if (end)
+				break;
+			end++;
+			continue;
+		}
+
+		entry = (struct apk_archive_entry){
+			.size  = GET_OCTAL(buf.size),
+			.uid   = GET_OCTAL(buf.uid),
+			.gid   = GET_OCTAL(buf.gid),
+			.mode  = GET_OCTAL(buf.mode) & 0777,
+			.mtime = GET_OCTAL(buf.mtime),
+			.name  = entry.name,
+			.uname = buf.uname,
+			.gname = buf.gname,
+			.device = makedev(GET_OCTAL(buf.devmajor),
+					  GET_OCTAL(buf.devminor)),
+			.read_fd = fd,
+		};
+
+		switch (buf.typeflag) {
+		case 'L':
+			if (entry.name != NULL)
+				free(entry.name);
+			entry.name = malloc(entry.size+1);
+			read(fd, entry.name, entry.size);
+			offset += entry.size;
+			entry.size = 0;
+			break;
+		case '0':
+		case '7': /* regular file */
+			entry.mode |= S_IFREG;
+			break;
+		case '1': /* hard link */
+			entry.mode |= S_IFREG;
+			entry.link_target = buf.linkname;
+			break;
+		case '2': /* symbolic link */
+			entry.mode |= S_IFLNK;
+			entry.link_target = buf.linkname;
+			break;
+		case '3': /* char device */
+			entry.mode |= S_IFCHR;
+			break;
+		case '4': /* block devicek */
+			entry.mode |= S_IFBLK;
+			break;
+		case '5': /* directory */
+			entry.mode |= S_IFDIR;
+			break;
+		default:
+			break;
+		}
+
+		if (entry.mode & S_IFMT) {
+			if (entry.name == NULL)
+				entry.name = strdup(buf.name);
+
+			/* callback parser function */
+			offset += entry.size;
+			r = parser(&entry, ctx);
+			if (r != 0)
+				return r;
+			offset -= entry.size;
+
+			free(entry.name);
+			entry.name = NULL;
+		}
+
+		if (entry.size)
+			offset += do_splice(fd, get_dev_null(), entry.size);
+
+		/* align to next 512 block */
+		if (offset & 511)
+			offset += do_splice(fd, get_dev_null(),
+					    512 - (offset & 511));
+	}
+
+	return 0;
+}
+
+int apk_parse_tar_gz(int fd, apk_archive_entry_parser parser, void *ctx)
+{
+	pid_t pid;
+	int r, status;
+
+	pid = apk_open_gz(&fd);
+	if (pid < 0)
+		return pid;
+
+	r = apk_parse_tar(fd, parser, ctx);
+	close(fd);
+	waitpid(pid, &status, 0);
+
+	return r;
+}
+
+apk_blob_t apk_archive_entry_read(struct apk_archive_entry *ae)
+{
+	char *str;
+	int pos = 0;
+	ssize_t r;
+
+	str = malloc(ae->size + 1);
+	pos = 0;
+	while (ae->size) {
+		r = read(ae->read_fd, &str[pos], ae->size);
+		if (r < 0) {
+			free(str);
+			return APK_BLOB_NULL;
+		}
+		pos += r;
+		ae->size -= r;
+	}
+	str[pos] = 0;
+
+	return APK_BLOB_PTR_LEN(str, pos+1);
+}
+
+int apk_archive_entry_extract(struct apk_archive_entry *ae, const char *fn)
+{
+	int r = -1;
+
+	if (fn == NULL)
+		fn = ae->name;
+
+	/* BIG HONKING FIXME */
+	unlink(fn);
+
+	switch (ae->mode & S_IFMT) {
+	case S_IFDIR:
+		r = mkdir(fn, ae->mode & 0777);
+		if (r < 0 && errno == EEXIST)
+			r = 0;
+		break;
+	case S_IFREG:
+		if (ae->link_target == NULL) {
+			r = open(fn, O_WRONLY | O_CREAT, ae->mode & 0777);
+			if (r < 0)
+				break;
+			ae->size -= do_splice(ae->read_fd, r, ae->size);
+			close(r);
+			r = ae->size ? -1 : 0;
+		} else {
+			r = link(ae->link_target, fn);
+		}
+		break;
+	case S_IFLNK:
+		r = symlink(ae->link_target, fn);
+		break;
+	case S_IFSOCK:
+	case S_IFBLK:
+	case S_IFCHR:
+	case S_IFIFO:
+		r = mknod(fn, ae->mode, ae->device);
+		break;
+	}
+	if (r != 0)
+		apk_error("Failed to extract %s\n", ae->name);
+	return r;
+}
+
+struct checksum_and_tee {
+	int in_fd, tee_fd;
+	void *ptr;
+};
+
+static void *__apk_checksum_and_tee(void *arg)
+{
+	struct checksum_and_tee *args = (struct checksum_and_tee *) arg;
+	char buf[2*1024];
+	int r, w, wt;
+	__off64_t offset;
+	csum_ctx_t ctx;
+	int dosplice = 1;
+
+	offset = lseek(args->in_fd, 0, SEEK_CUR);
+	csum_init(&ctx);
+	do {
+		r = read(args->in_fd, buf, sizeof(buf));
+		if (r <= 0)
+			break;
+
+		wt = 0;
+		do {
+			if (dosplice) {
+				w = splice(args->in_fd, &offset, args->tee_fd, NULL,
+					   r - wt, SPLICE_F_MOVE);
+				if (w < 0) {
+					dosplice = 0;
+					continue;
+				}
+			} else {
+				w = write(args->tee_fd, &buf[wt], r - wt);
+				if (w < 0)
+					break;
+			}
+			wt += w;
+		} while (wt != r);
+
+		csum_process(&ctx, buf, r);
+	} while (r == sizeof(buf));
+
+	csum_finish(&ctx, args->ptr);
+	close(args->tee_fd);
+	close(args->in_fd);
+	free(args);
+
+	return NULL;
+}
+
+pthread_t apk_checksum_and_tee(int *fd, void *ptr)
+{
+	struct checksum_and_tee *args;
+	int fds[2];
+	pthread_t tid;
+
+	if (pipe(fds) < 0)
+		return -1;
+
+	fcntl(fds[0], F_SETFD, FD_CLOEXEC);
+	fcntl(fds[1], F_SETFD, FD_CLOEXEC);
+
+	args = malloc(sizeof(*args));
+	*args = (struct checksum_and_tee){ *fd, fds[1], ptr };
+	if (pthread_create(&tid, NULL, __apk_checksum_and_tee, args) < 0)
+		return -1;
+
+	*fd = fds[0];
+	return tid;
+}
+