diff options
Diffstat (limited to 'src/archive.c')
| -rw-r--r-- | src/archive.c | 349 |
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; +} + |