From 21287daef23e8ca6acd60af8b997ae119095dbc0 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Sat, 16 Mar 2019 20:06:24 -0500 Subject: Next round of tar cleanup. --- toys/pending/tar.c | 361 ++++++++++++++++++++++++----------------------------- 1 file changed, 164 insertions(+), 197 deletions(-) (limited to 'toys/pending') diff --git a/toys/pending/tar.c b/toys/pending/tar.c index 6bb2b0e9..1f7acebf 100644 --- a/toys/pending/tar.c +++ b/toys/pending/tar.c @@ -115,11 +115,20 @@ static struct inode_list *seen_inode(void **list, struct stat *st, char *name) return 0; } +// Calculate packet checksum, with cksum field treated as 8 spaces +static unsigned cksum(void *data) +{ + unsigned i, cksum = 8*' '; + + for (i = 0; i<500; i += (i==147) ? 9 : 1) cksum += ((char *)data)[i]; + + return cksum; +} + static void write_longname(char *name, char type) { struct tar_hdr tmp[2]; - unsigned int sum = 0; - int i, sz = strlen(name) +1; + int sz = strlen(name) +1; memset(tmp, 0, sizeof(tmp)); strcpy(tmp->name, "././@LongLink"); @@ -132,10 +141,7 @@ static void write_longname(char *name, char type) strcpy(tmp->magic, "ustar "); // Calculate checksum - memset(tmp->chksum, ' ', 8); - for (i = 0; i < 512; i++) sum += ((char *)tmp)[i]; -// TODO: why is this -1 when the rest aren't? - itoo(tmp->chksum, sizeof(tmp->chksum)-1, sum); + itoo(tmp->chksum, sizeof(tmp->chksum), cksum(&tmp)); // write header and name, padded with NUL to block size xwrite(TT.fd, tmp, sizeof(*tmp)); @@ -170,6 +176,7 @@ static void alloread(void *buf, int len) free(*b); *b = xmalloc(len+1); xreadall(TT.fd, *b, len); + b[len] = 0; TT.offset += len; } @@ -181,7 +188,6 @@ static void add_file(char **nam, struct stat *st) struct inode_list *node = node; int i, fd =-1; char *c, *p, *name = *nam, *lnk, *hname, buf[512] = {0,}; - unsigned int sum = 0; static int warn = 1; for (p = name; *p; p++) @@ -210,7 +216,6 @@ static void add_file(char **nam, struct stat *st) itoo(hdr.gid, sizeof(hdr.gid), st->st_gid); itoo(hdr.size, sizeof(hdr.size), 0); //set size later itoo(hdr.mtime, sizeof(hdr.mtime), st->st_mtime); - memset(hdr.chksum, ' ', sizeof(hdr.chksum)); // Hard link or symlink? i = !!S_ISLNK(st->st_mode); @@ -252,9 +257,7 @@ static void add_file(char **nam, struct stat *st) snprintf(hdr.gname, sizeof(hdr.gname), "%s", gr->gr_name); else sprintf(hdr.gname, "%d", st->st_gid); - //calculate chksum. - for (i = 0; i < 512; i++) sum += ((char*)&hdr)[i]; - itoo(hdr.chksum, sizeof(hdr.chksum)-1, sum); + itoo(hdr.chksum, sizeof(hdr.chksum)-1, cksum(&hdr)); if (FLAG(v)) printf("%s\n",hname); xwrite(TT.fd, (void*)&hdr, 512); @@ -306,10 +309,10 @@ static void extract_to_command(struct archive_handler *tar) { int pipefd[2], status = 0; pid_t cpid; - struct file_header *file_hdr = &tar->file_hdr; + struct file_header *hdr = &tar->file_hdr; xpipe(pipefd); - if (!S_ISREG(file_hdr->mode)) return; //only regular files are supported. + if (!S_ISREG(hdr->mode)) return; //only regular files are supported. cpid = fork(); if (cpid == -1) perror_exit("fork"); @@ -318,18 +321,18 @@ static void extract_to_command(struct archive_handler *tar) char buf[64], *argv[4] = {"sh", "-c", TT.to_command, NULL}; setenv("TAR_FILETYPE", "f", 1); - sprintf(buf, "%0o", file_hdr->mode); + sprintf(buf, "%0o", hdr->mode); setenv("TAR_MODE", buf, 1); - sprintf(buf, "%ld", (long)file_hdr->size); + sprintf(buf, "%ld", (long)hdr->size); setenv("TAR_SIZE", buf, 1); - setenv("TAR_FILENAME", file_hdr->name, 1); - setenv("TAR_UNAME", file_hdr->uname, 1); - setenv("TAR_GNAME", file_hdr->gname, 1); - sprintf(buf, "%0o", (int)file_hdr->mtime); + setenv("TAR_FILENAME", hdr->name, 1); + setenv("TAR_UNAME", hdr->uname, 1); + setenv("TAR_GNAME", hdr->gname, 1); + sprintf(buf, "%0o", (int)hdr->mtime); setenv("TAR_MTIME", buf, 1); - sprintf(buf, "%0o", file_hdr->uid); + sprintf(buf, "%0o", hdr->uid); setenv("TAR_UID", buf, 1); - sprintf(buf, "%0o", file_hdr->gid); + sprintf(buf, "%0o", hdr->gid); setenv("TAR_GID", buf, 1); xclose(pipefd[1]); // Close unused write @@ -338,7 +341,7 @@ static void extract_to_command(struct archive_handler *tar) xexec(argv); } else { xclose(pipefd[0]); // Close unused read end - sendlen(pipefd[1], file_hdr->size); + sendlen(pipefd[1], hdr->size); xclose(pipefd[1]); waitpid(cpid, &status, 0); if (WIFSIGNALED(status)) @@ -351,90 +354,90 @@ static void extract_to_disk(struct archive_handler *tar) int flags, dst_fd = -1; char *s; struct stat ex; - struct file_header *file_hdr = &tar->file_hdr; + struct file_header *hdr = &tar->file_hdr; // while not if - flags = strlen(file_hdr->name); + flags = strlen(hdr->name); if (flags>2) - if (strstr(file_hdr->name, "/../") || !strcmp(file_hdr->name, "../") || - !strcmp(file_hdr->name+flags-3, "/..")) - error_msg("drop %s", file_hdr->name); + if (strstr(hdr->name, "/../") || !strcmp(hdr->name, "../") || + !strcmp(hdr->name+flags-3, "/..")) + error_msg("drop %s", hdr->name); - if (file_hdr->name[flags-1] == '/') file_hdr->name[flags-1] = 0; + if (hdr->name[flags-1] == '/') hdr->name[flags-1] = 0; //Regular file with preceding path - if ((s = strrchr(file_hdr->name, '/'))) { - if (mkpath(file_hdr->name) && errno !=EEXIST) { - error_msg(":%s: not created", file_hdr->name); + if ((s = strrchr(hdr->name, '/'))) { + if (mkpath(hdr->name) && errno !=EEXIST) { + error_msg(":%s: not created", hdr->name); return; } } //remove old file, if exists - if (!FLAG(k) && !S_ISDIR(file_hdr->mode) && !lstat(file_hdr->name, &ex)) - if (unlink(file_hdr->name)) - perror_msg("can't remove: %s", file_hdr->name); + if (!FLAG(k) && !S_ISDIR(hdr->mode) && !lstat(hdr->name, &ex)) + if (unlink(hdr->name)) + perror_msg("can't remove: %s", hdr->name); //hard link - if (S_ISREG(file_hdr->mode) && file_hdr->link_target) { - if (link(file_hdr->link_target, file_hdr->name)) - perror_msg("can't link '%s' -> '%s'",file_hdr->name, file_hdr->link_target); + if (S_ISREG(hdr->mode) && hdr->link_target) { + if (link(hdr->link_target, hdr->name)) + perror_msg("can't link '%s' -> '%s'",hdr->name, hdr->link_target); goto COPY; } - switch (file_hdr->mode & S_IFMT) { + switch (hdr->mode & S_IFMT) { case S_IFREG: flags = O_WRONLY|O_CREAT|O_EXCL; if (FLAG(overwrite)) flags = O_WRONLY|O_CREAT|O_TRUNC; - dst_fd = open(file_hdr->name, flags, file_hdr->mode & 07777); - if (dst_fd == -1) perror_msg("%s: can't open", file_hdr->name); + dst_fd = open(hdr->name, flags, hdr->mode & 07777); + if (dst_fd == -1) perror_msg("%s: can't open", hdr->name); break; case S_IFDIR: - if ((mkdir(file_hdr->name, file_hdr->mode) == -1) && errno != EEXIST) - perror_msg("%s: can't create", file_hdr->name); + if ((mkdir(hdr->name, hdr->mode) == -1) && errno != EEXIST) + perror_msg("%s: can't create", hdr->name); break; case S_IFLNK: - if (symlink(file_hdr->link_target, file_hdr->name)) - perror_msg("can't link '%s' -> '%s'",file_hdr->name, file_hdr->link_target); + if (symlink(hdr->link_target, hdr->name)) + perror_msg("can't link '%s' -> '%s'",hdr->name, hdr->link_target); break; case S_IFBLK: case S_IFCHR: case S_IFIFO: - if (mknod(file_hdr->name, file_hdr->mode, file_hdr->device)) - perror_msg("can't create '%s'", file_hdr->name); + if (mknod(hdr->name, hdr->mode, hdr->device)) + perror_msg("can't create '%s'", hdr->name); break; default: - printf("type %o not supported\n", file_hdr->mode); + printf("type %o not supported\n", hdr->mode); break; } //copy file.... COPY: - sendlen(dst_fd, file_hdr->size); + sendlen(dst_fd, hdr->size); close(dst_fd); - if (S_ISLNK(file_hdr->mode)) return; + if (S_ISLNK(hdr->mode)) return; if (!FLAG(o)) { //set ownership..., --no-same-owner, --numeric-owner - uid_t u = file_hdr->uid; - gid_t g = file_hdr->gid; + uid_t u = hdr->uid; + gid_t g = hdr->gid; if (!FLAG(numeric_owner)) { - struct group *gr = getgrnam(file_hdr->gname); - struct passwd *pw = getpwnam(file_hdr->uname); + struct group *gr = getgrnam(hdr->gname); + struct passwd *pw = getpwnam(hdr->uname); if (pw) u = pw->pw_uid; if (gr) g = gr->gr_gid; } - if (!geteuid() && chown(file_hdr->name, u, g)) - perror_msg("chown %d:%d '%s'", u, g, file_hdr->name);; + if (!geteuid() && chown(hdr->name, u, g)) + perror_msg("chown %d:%d '%s'", u, g, hdr->name);; } if (FLAG(p)) // || !FLAG(no_same_permissions)) - chmod(file_hdr->name, file_hdr->mode); + chmod(hdr->name, hdr->mode); //apply mtime if (!FLAG(m)) { - struct timeval times[2] = {{file_hdr->mtime, 0},{file_hdr->mtime, 0}}; - utimes(file_hdr->name, times); + struct timeval times[2] = {{hdr->mtime, 0},{hdr->mtime, 0}}; + utimes(hdr->name, times); } } @@ -460,190 +463,147 @@ static void file_to_list(char *file, struct arg_list **llist) } //convert octal to int -static int otoi(char *str, int len) +static unsigned long long otoi(char *str, int len) { - long val; - char *endp, inp[len+1]; //1 for NUL termination - - memcpy(inp, str, len); - inp[len] = '\0'; //nul-termination made sure - val = strtol(inp, &endp, 8); - if (*endp && *endp != ' ') error_exit("invalid param"); - return (int)val; -} + unsigned long long val; -static char *process_extended_hdr(struct archive_handler *tar, int size) -{ - char *value = NULL, *p, *buf = 0; - - alloread(&buf, size); - buf[size] = 0; - p = buf; - - while (size) { - char *key; - int len, n; - - // extended records are of the format: "LEN NAME=VALUE\n" - sscanf(p, "%d %n", &len, &n); - key = p + n; - p += len; - size -= len; - p[-1] = 0; - if (size < 0) { - error_msg("corrupted extended header"); - break; - } +// todo: base-256 encoding, just do it symmetrically for all fields + str[len-1] = 0; + val = strtoull(str, &str, 8); + if (*str && *str != ' ') error_exit("bad header"); - len = strlen("path="); - if (!strncmp(key, "path=", len)) { - value = key + strlen("path="); - break; - } - } - if (value) value = xstrdup(value); - free(buf); - return value; + return val; } static void unpack_tar(void) { struct archive_handler *tar_hdl = TT.handle; + struct file_header *hdr = &tar_hdl->file_hdr; struct tar_hdr tar; - struct file_header *file_hdr; - int i, j, maj, min, sz, e = 0; - unsigned int cksum; + int i; char *s; for (;;) { // align to next block and read it + if (hdr->size%512) skippy(512-hdr->size%512); // This is the only consumer of TT.offset - if (TT.offset&511) skippy(512-TT.offset%512); - i = readall(TT.fd, &tar, 512); - if (i != 512) { - if (i >= 2) goto CHECK_MAGIC; //may be a small (<512 byte)zipped file - error_exit("read error"); - } +// if (TT.offset&511) skippy(512-TT.offset%512); - if (!tar.name[0]) { - if (e) return; //end of tar 2 empty blocks - e = 1;//empty jump to next block -// never clear e, so they don't have to be _consecutive_??? - continue; - } -// can you append a bzip to a gzip _within_ a tarball? Nested compress? -// Or compressed data after uncompressed data? - if (strncmp(tar.magic, "ustar", 5)) { - // Try detecting .gz or .bz2 by looking for their magic. -CHECK_MAGIC: - if ((!strncmp(tar.name, "\x1f\x8b", 2) || !strncmp(tar.name, "BZh", 3)) - && !lseek(TT.fd, -i, SEEK_CUR)) { - toys.optflags |= (*tar.name == 'B') ? FLAG_j : FLAG_z; - extract_stream(tar_hdl); - continue; - } - error_exit("invalid tar format"); - } -// moved this down here so it doesn't have to be undone + i = readall(TT.fd, &tar, 512); + if (i != 512) error_exit("read error"); TT.offset += i; + // ensure null temination even of pathological packets + tar.padd[0] = 0; - // Calculate checksum, with cksum field treated as eight spaces - cksum = 8*' '; - for (j = 0; j<500; j += (j==147) ? 9 : 1) cksum += ((char*)&tar)[j]; - - if (cksum != otoi(tar.chksum, sizeof(tar.chksum))) error_exit("bad cksum"); - - file_hdr = &tar_hdl->file_hdr; - memset(file_hdr, 0, sizeof(struct file_header)); - file_hdr->mode = otoi(tar.mode, sizeof(tar.mode)); - file_hdr->uid = otoi(tar.uid, sizeof(tar.uid)); - file_hdr->gid = otoi(tar.gid, sizeof(tar.gid)); - file_hdr->size = otoi(tar.size, sizeof(tar.size)); - file_hdr->mtime = otoi(tar.mtime, sizeof(tar.mtime)); - file_hdr->uname = xstrdup(tar.uname); - file_hdr->gname = xstrdup(tar.gname); - maj = otoi(tar.major, sizeof(tar.major)); - min = otoi(tar.minor, sizeof(tar.minor)); - file_hdr->device = dev_makedev(maj, min); - - if (tar.type <= '7') { - if (tar.link[0]) { - sz = sizeof(tar.link); - file_hdr->link_target = xmalloc(sz + 1); - memcpy(file_hdr->link_target, tar.link, sz); - file_hdr->link_target[sz] = '\0'; - } + // End of tar + if (!*tar.name) return; - file_hdr->name = xzalloc(256);// pathname supported size - if (tar.prefix[0]) { - memcpy(file_hdr->name, tar.prefix, sizeof(tar.prefix)); - sz = strlen(file_hdr->name); - if (file_hdr->name[sz-1] != '/') file_hdr->name[sz] = '/'; - } - sz = strlen(file_hdr->name); - memcpy(file_hdr->name + sz, tar.name, sizeof(tar.name)); -// TODO: won't the vfs tell us? - if (file_hdr->name[255]) error_exit("filename too long"); - } +// can you append a bzip to a gzip _within_ a tarball? Nested compress? +// Or compressed data after uncompressed data? + if (memcmp(tar.magic, "ustar", 5)) error_exit("bad header"); + + if (cksum(&tar) != otoi(tar.chksum, sizeof(tar.chksum))) + error_exit("bad cksum"); + + hdr->size = otoi(tar.size, sizeof(tar.size)); + + // Write something to the filesystem? + if (tar.type>='0' && tar.type<='7') { + hdr->mode = otoi(tar.mode, sizeof(tar.mode)); + hdr->mode |= (char []){8,8,10,2,6,4,1,8}[tar.type-'0']<<12; + hdr->uid = otoi(tar.uid, sizeof(tar.uid)); + hdr->gid = otoi(tar.gid, sizeof(tar.gid)); + hdr->mtime = otoi(tar.mtime, sizeof(tar.mtime)); + hdr->device = dev_makedev(otoi(tar.major, sizeof(tar.major)), + otoi(tar.minor, sizeof(tar.minor))); + hdr->uname = xstrndup(tar.uname, sizeof(tar.uname)); + hdr->gname = xstrndup(tar.gname, sizeof(tar.gname)); + if (!hdr->link_target && *tar.link) + hdr->link_target = xstrndup(tar.link, sizeof(tar.link)); + if (!hdr->name) + hdr->name = xmprintf("%.*s%s%.*s", (int)sizeof(tar.prefix), tar.prefix, + (!*tar.prefix || tar.prefix[strlen(tar.prefix)-1] == '/') ? "" : "/", + (int)sizeof(tar.name), tar.name); + + // Other headers don't immediately result in creating a new node + } else { - // Headers that don't immediately result in creating a new node - if (strchr("KLxDMNSVg", tar.type)) { - if (tar.type == 'K') alloread(&file_hdr->link_target, file_hdr->size); - else if (tar.type == 'L') alloread(&file_hdr->name, file_hdr->size); - else if (tar.type == 'x') process_extended_hdr(tar_hdl, file_hdr->size); - else skippy(file_hdr->size); + if (tar.type == 'K') alloread(&hdr->link_target, hdr->size); + else if (tar.type == 'L') alloread(&hdr->name, hdr->size); + else if (tar.type == 'x') { + char *p, *buf = 0; + int i, len, n; + + // Posix extended record "LEN NAME=VALUE\n" format + alloread(&buf, hdr->size); + for (p = buf; (p-buf)size; p += len) { + if ((i = sscanf(p, "%u path=%n", &len, &n))<1 || len<4 || + len>hdr->size) + { + error_msg("corrupted extended header"); + break; + } + p[len-1] = 0; + if (i == 2) { + hdr->name = xstrdup(p+n); + break; + } + } + free(buf); + + // This could be if (strchr("DMNSVg", tar.type)) but an unknown header + // type with trailing contents is unlikely to have a valid type & cksum + // if the contents interpreted as a header + } else skippy(hdr->size); continue; } - // Specified file type? - if (isdigit(tar.type)) - file_hdr->mode |= (char []){8,8,10,2,6,4,1,8,0,0}[tar.type-'0']<<12; - // Directories sometimes recorded as "file with trailing slash" - if (S_ISREG(file_hdr->mode) && (s = strend(file_hdr->name, "/"))) { + if (S_ISREG(hdr->mode) && (s = strend(hdr->name, "/"))) { *s = 0; - file_hdr->mode = (file_hdr->mode & ~S_IFMT) | S_IFDIR; + hdr->mode = (hdr->mode & ~S_IFMT) | S_IFDIR; } // TODO: what? - if ((file_hdr->link_target && *(file_hdr->link_target)) - || S_ISLNK(file_hdr->mode) || S_ISDIR(file_hdr->mode)) - file_hdr->size = 0; + if ((hdr->link_target && *(hdr->link_target)) + || S_ISLNK(hdr->mode) || S_ISDIR(hdr->mode)) + hdr->size = 0; // Skip excluded files - if (filter(TT.exc, file_hdr->name) || - (TT.inc && !filter(TT.inc, file_hdr->name))) { - skippy(file_hdr->size); + if (filter(TT.exc, hdr->name) || + (TT.inc && !filter(TT.inc, hdr->name))) { + skippy(hdr->size); // TODO: awkward goto FREE; } // TODO: wrong, shouldn't grow endlessly, mark seen TT.inc instead - add_to_list(&TT.pass, xstrdup(file_hdr->name)); + add_to_list(&TT.pass, xstrdup(hdr->name)); if (FLAG(t)) { if (FLAG(v)) { char perm[11]; - struct tm *lc = localtime((const time_t*)&(file_hdr->mtime)); + struct tm *lc = localtime((const time_t*)&(hdr->mtime)); - mode_to_string(file_hdr->mode, perm); - printf("%s %s/%s %9ld %d-%02d-%02d %02d:%02d:%02d ",perm,file_hdr->uname, - file_hdr->gname, (long)file_hdr->size, 1900+lc->tm_year, + mode_to_string(hdr->mode, perm); + printf("%s %s/%s %9ld %d-%02d-%02d %02d:%02d:%02d ", perm, hdr->uname, + hdr->gname, (long)hdr->size, 1900+lc->tm_year, 1+lc->tm_mon, lc->tm_mday, lc->tm_hour, lc->tm_min, lc->tm_sec); } - printf("%s",file_hdr->name); - if (file_hdr->link_target) printf(" -> %s",file_hdr->link_target); + printf("%s", hdr->name); + if (hdr->link_target) printf(" -> %s", hdr->link_target); xputc('\n'); - skippy(file_hdr->size); + skippy(hdr->size); } else { - if (FLAG(v)) printf("%s\n",file_hdr->name); + if (FLAG(v)) printf("%s\n", hdr->name); tar_hdl->extract_handler(tar_hdl); } FREE: - free(file_hdr->name); - free(file_hdr->link_target); - free(file_hdr->uname); - free(file_hdr->gname); + free(hdr->name); + free(hdr->link_target); + free(hdr->uname); + free(hdr->gname); + memset(hdr, 0, sizeof(struct file_header)); } } @@ -686,6 +646,14 @@ void tar_main(void) if (FLAG(to_command)) tar_hdl->extract_handler = extract_to_command; // TODO: autodtect + +// Try detecting .gz or .bz2 by looking for their magic. +// if ((!memcmp(tar.name, "\x1f\x8b", 2) || !memcmp(tar.name, "BZh", 3)) +// && !lseek(TT.fd, -i, SEEK_CUR)) { +// toys.optflags |= (*tar.name == 'B') ? FLAG_j : FLAG_z; +// extract_stream(tar_hdl); +// continue; +// } if (FLAG(j)||FLAG(z)) extract_stream(tar_hdl); unpack_tar(); @@ -703,7 +671,6 @@ void tar_main(void) close(TT.fd); TT.fd = pipefd[0]; } -// TODO cowardly empty archive for (tmp = TT.inc; tmp; tmp = tmp->next) dirtree_flagread(tmp->arg, FLAG(h)?DIRTREE_SYMFOLLOW:0, add_to_tar); -- cgit v1.2.3