diff options
Diffstat (limited to 'lib/fstree/fstree_from_file.c')
| -rw-r--r-- | lib/fstree/fstree_from_file.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/lib/fstree/fstree_from_file.c b/lib/fstree/fstree_from_file.c new file mode 100644 index 0000000..66d71a2 --- /dev/null +++ b/lib/fstree/fstree_from_file.c @@ -0,0 +1,436 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "fstree.h" + +#include <sys/sysmacros.h> +#include <sys/types.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <stdio.h> +#include <ctype.h> +#include <errno.h> + +static int add_dir(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + if (extra != NULL && *extra != '\0') { + fprintf(stderr, "%s: %zu: WARNING: ignoring extra arguments\n", + filename, line_num); + } + + if (fstree_add(fs, path, S_IFDIR | mode, uid, gid, 0) == NULL) { + fprintf(stderr, "%s: %zu: mkdir -p %s: %s\n", + filename, line_num, path, strerror(errno)); + return -1; + } + + return 0; +} + +static int add_slink(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + tree_node_t *node; + (void)mode; + + if (extra == NULL || *extra == '\0') { + fprintf(stderr, "%s: %zu: missing symlink target\n", + filename, line_num); + return -1; + } + + node = fstree_add(fs, path, S_IFLNK | 0777, uid, gid, + strlen(extra) + 1); + + if (node == NULL) { + fprintf(stderr, "%s: %zu: ln -s %s %s\n", + filename, line_num, extra, path); + return -1; + } + + strcpy(node->data.slink_target, extra); + return 0; +} + +static int add_device(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + unsigned int maj = 0, min = 0; + tree_node_t *node; + + if (extra == NULL || *extra == '\0') { + fprintf(stderr, "%s: %zu: missing device type\n", + filename, line_num); + return -1; + } + + if ((*extra == 'c' || *extra == 'C') && isspace(extra[1])) { + mode |= S_IFCHR; + } else if ((*extra == 'b' || *extra == 'B') && isspace(extra[1])) { + mode |= S_IFBLK; + } else { + fprintf(stderr, "%s: %zu: unsupported device type", + filename, line_num); + return -1; + } + + ++extra; + while (isspace(*extra)) + ++extra; + + if (!isdigit(*extra)) + goto fail_devno; + + while (isdigit(*extra)) + maj = maj * 10 + *(extra++) - '0'; + + if (*(extra++) != ':') + goto fail_devno; + + if (!isdigit(*extra)) + goto fail_devno; + + while (isdigit(*extra)) + min = min * 10 + *(extra++) - '0'; + + while (isspace(*extra)) + ++extra; + + if (*extra != '\0') { + fprintf(stderr, "%s: %zu: WARNING: ignoring extra arguments\n", + filename, line_num); + } + + node = fstree_add(fs, path, mode, uid, gid, 0); + if (node == NULL) { + fprintf(stderr, "%s: %zu: mknod %s %c %u %u: %s\n", + filename, line_num, path, S_ISCHR(mode) ? 'c' : 'b', + maj, min, strerror(errno)); + return -1; + } + + node->data.devno = makedev(maj, min); + return 0; +fail_devno: + fprintf(stderr, "%s: %zu: error in device number format\n", + filename, line_num); + return -1; +} + +static int add_pipe(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + if (extra != NULL && *extra != '\0') { + fprintf(stderr, "%s: %zu: WARNING: ignoring extra arguments\n", + filename, line_num); + } + + if (fstree_add(fs, path, S_IFIFO | mode, uid, gid, 0) == NULL) { + fprintf(stderr, "%s: %zu: mkfifo %s: %s\n", + filename, line_num, path, strerror(errno)); + return -1; + } + + return 0; +} + +static int add_socket(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + if (extra != NULL && *extra != '\0') { + fprintf(stderr, "%s: %zu: WARNING: ignoring extra arguments\n", + filename, line_num); + } + + if (fstree_add(fs, path, S_IFSOCK | mode, uid, gid, 0) == NULL) { + fprintf(stderr, "%s: %zu: creating Unix socket %s: %s\n", + filename, line_num, path, strerror(errno)); + return -1; + } + + return 0; +} + +static int add_file(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra) +{ + char *infile = NULL; + tree_node_t *node; + const char *ptr; + struct stat sb; + int ret; + + ptr = strrchr(filename, '/'); + + if (extra == NULL || *extra == '\0') { + if (ptr == NULL) { + extra = path; + } else { + ret = asprintf(&infile, "%.*s/%s", + (int)(filename - ptr), filename, path); + if (ret < 0) + goto fail_asprintf; + } + } else if (*extra != '/' && ptr != NULL) { + ret = asprintf(&infile, "%.*s/%s", + (int)(filename - ptr), filename, extra); + if (ret < 0) + goto fail_asprintf; + } + + if (infile != NULL) + extra = infile; + + if (stat(extra, &sb) != 0) { + fprintf(stderr, "%s: %zu: stat %s: %s\n", filename, line_num, + extra, strerror(errno)); + goto fail; + } + + node = fstree_add_file(fs, path, mode, uid, gid, sb.st_size, extra); + + if (node == NULL) { + fprintf(stderr, "%s: %zu: adding %s as %s: %s\n", + filename, line_num, extra, path, strerror(errno)); + goto fail; + } + + free(infile); + return 0; +fail: + free(infile); + return -1; +fail_asprintf: + fprintf(stderr, "%s: %zu: pasting together file path: %s\n", + filename, line_num, strerror(errno)); + return -1; +} + +static const struct { + const char *keyword; + int (*callback)(fstree_t *fs, const char *filename, size_t line_num, + const char *path, uint16_t mode, uint32_t uid, + uint32_t gid, const char *extra); +} file_list_hooks[] = { + { "dir", add_dir }, + { "slink", add_slink }, + { "nod", add_device }, + { "pipe", add_pipe }, + { "pipe", add_socket }, + { "file", add_file }, +}; + +#define NUM_HOOKS (sizeof(file_list_hooks) / sizeof(file_list_hooks[0])) + +static void trim_line(char *line) +{ + size_t i; + + for (i = 0; isspace(line[i]); ++i) + ; + + if (line[i] == '#') { + line[0] = '\0'; + return; + } + + if (i > 0) + memmove(line, line + i, strlen(line + i) + 1); + + i = strlen(line); + while (i > 0 && isspace(line[i - 1])) + --i; + + line[i] = '\0'; +} + +static int handle_line(fstree_t *fs, const char *filename, + size_t line_num, char *line) +{ + const char *path, *extra = NULL, *msg = NULL; + unsigned int mode = 0, uid = 0, gid = 0, x; + char keyword[16]; + size_t i; + + /* isolate keyword */ + for (i = 0; isalpha(line[i]); ++i) + ; + + if (i >= sizeof(keyword) || i == 0 || !isspace(line[i])) + goto fail_ent; + + memcpy(keyword, line, i); + keyword[i] = '\0'; + + while (isspace(line[i])) + ++i; + + /* isolate path */ + path = line + i; + + for (; line[i] != '\0'; ++i) { + /* TODO: escape sequences to support spaces in path */ + + if (isspace(line[i])) + break; + } + + if (!isspace(line[i])) + goto fail_ent; + + line[i++] = '\0'; + while (isspace(line[i])) + ++i; + + /* mode */ + if (!isdigit(line[i])) + goto fail_mode; + + for (; isdigit(line[i]); ++i) { + if (line[i] > '7') + goto fail_mode; + + mode = (mode << 3) | (line[i] - '0'); + + if (mode > 07777) + goto fail_mode_bits; + } + + if (!isspace(line[i])) + goto fail_ent; + + while (isspace(line[i])) + ++i; + + /* uid */ + if (!isdigit(line[i])) + goto fail_uid_gid; + + for (; isdigit(line[i]); ++i) { + x = line[i] - '0'; + + if (uid > (0xFFFFFFFF - x) / 10) + goto fail_ov; + + uid = uid * 10 + x; + } + + if (!isspace(line[i])) + goto fail_ent; + + while (isspace(line[i])) + ++i; + + /* gid */ + if (!isdigit(line[i])) + goto fail_uid_gid; + + for (; isdigit(line[i]); ++i) { + x = line[i] - '0'; + + if (gid > (0xFFFFFFFF - x) / 10) + goto fail_ov; + + gid = gid * 10 + x; + } + + /* extra */ + if (isspace(line[i])) { + while (isspace(line[i])) + ++i; + + if (line[i] != '\0') + extra = line + i; + } + + /* forward to callback */ + for (i = 0; i < NUM_HOOKS; ++i) { + if (strcmp(file_list_hooks[i].keyword, keyword) == 0) { + return file_list_hooks[i].callback(fs, filename, + line_num, path, + mode, uid, gid, + extra); + } + } + + fprintf(stderr, "%s: %zu: unknown entry type '%s'.\n", filename, + line_num, keyword); + return -1; +fail_ov: + msg = "numeric overflow"; + goto fail_ent; +fail_uid_gid: + msg = "uid & gid must be decimal numbers"; + goto out_desc; +fail_mode: + msg = "mode must be an octal number"; + goto out_desc; +fail_mode_bits: + msg = "you can only set the permission bits in the mode"; + goto out_desc; +fail_ent: + msg = "error in entry description"; + goto out_desc; +out_desc: + fprintf(stderr, "%s: %zu: %s.\n", filename, line_num, msg); + fputs("expected: <type> <path> <mode> <uid> <gid> [<extra>]\n", + stderr); + return -1; +} + +int fstree_from_file(fstree_t *fs, const char *filename) +{ + FILE *fp = fopen(filename, "rb"); + size_t n, line_num = 0; + ssize_t ret; + char *line; + + if (fp == NULL) { + perror(filename); + return -1; + } + + for (;;) { + line = NULL; + n = 0; + errno = 0; + + ret = getline(&line, &n, fp); + ++line_num; + + if (ret < 0) { + if (errno == 0) { + free(line); + break; + } + + perror(filename); + goto fail_line; + } + + trim_line(line); + + if (line[0] == '\0') { + free(line); + continue; + } + + if (handle_line(fs, filename, line_num, line)) + goto fail_line; + + free(line); + } + + fclose(fp); + return 0; +fail_line: + free(line); + fclose(fp); + return -1; +} |