-/* $OpenBSD: file.c,v 1.34 2015/04/26 22:51:32 nicm Exp $ */
+/* $OpenBSD: file.c,v 1.35 2015/04/27 13:41:45 nicm Exp $ */
/*
* Copyright (c) 2015 Nicholas Marriott <nicm@openbsd.org>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/queue.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
#include <errno.h>
+#include <imsg.h>
#include <libgen.h>
#include <getopt.h>
#include <fcntl.h>
#include "magic.h"
#include "xmalloc.h"
-struct input_file
+struct input_msg
{
- struct magic *m;
+ int idx;
- const char *path;
- const char *label;
+ struct stat sb;
+ int error;
- int fd;
- struct stat sb;
- const char *error;
+ char link_path[PATH_MAX];
+ int link_error;
+ int link_target;
+};
+
+struct input_ack
+{
+ int idx;
+};
+
+struct input_file
+{
+ struct magic *m;
+ struct input_msg *msg;
- void *base;
- size_t size;
- int mapped;
- char *result;
+ const char *path;
+ int fd;
- char link_path[PATH_MAX];
- const char *link_error;
- int link_target;
+ void *base;
+ size_t size;
+ int mapped;
+ char *result;
};
extern char *__progname;
__dead void usage(void);
-static void prepare_file(struct input_file *, const char *, int *);
-static void open_file(struct input_file *);
-static void read_link(struct input_file *);
-static void test_file(struct magic *, struct input_file *, int);
+static void send_message(struct imsgbuf *, void *, size_t, int);
+static int read_message(struct imsgbuf *, struct imsg *, pid_t);
+
+static void read_link(struct input_msg *, const char *);
+
+static __dead void child(int, pid_t, int, char **);
+
+static void test_file(struct input_file *, size_t);
static int try_stat(struct input_file *);
static int try_empty(struct input_file *);
static int sflag;
static int Wflag;
+static char *magicpath;
+static FILE *magicfp;
+
static struct option longopts[] = {
{ "mime", no_argument, NULL, 'i' },
{ "mime-type", no_argument, NULL, 'i' },
int
main(int argc, char **argv)
{
- struct input_file *files = NULL;
- int opt, i, width = 0;
- FILE *f;
- struct magic *m;
- char *home, *path;
+ int opt, pair[2], fd, idx;
+ char *home;
struct passwd *pw;
+ struct imsgbuf ibuf;
+ struct imsg imsg;
+ struct input_msg msg;
+ struct input_ack *ack;
+ pid_t pid, parent;
for (;;) {
opt = getopt_long(argc, argv, "bchiLsW", longopts, NULL);
} else if (argc == 0)
usage();
- f = NULL;
+ magicfp = NULL;
if (geteuid() != 0 && !issetugid()) {
home = getenv("HOME");
if (home == NULL || *home == '\0') {
home = NULL;
}
if (home != NULL) {
- xasprintf(&path, "%s/.magic", home);
- f = fopen(path, "r");
- if (f == NULL && errno != ENOENT)
- err(1, "%s", path);
- if (f == NULL)
- free(path);
+ xasprintf(&magicpath, "%s/.magic", home);
+ magicfp = fopen(magicpath, "r");
+ if (magicfp == NULL && errno != ENOENT)
+ err(1, "%s", magicpath);
+ if (magicfp == NULL)
+ free(magicpath);
}
}
- if (f == NULL) {
- path = xstrdup("/etc/magic");
- f = fopen(path, "r");
+ if (magicfp == NULL) {
+ magicpath = xstrdup("/etc/magic");
+ magicfp = fopen(magicpath, "r");
}
- if (f == NULL)
- err(1, "%s", path);
+ if (magicfp == NULL)
+ err(1, "%s", magicpath);
+
+ parent = getpid();
+ if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
+ err(1, "socketpair");
+ switch (pid = fork()) {
+ case 0:
+ close(pair[0]);
+ child(pair[1], parent, argc, argv);
+ case -1:
+ err(1, "fork");
+ }
+ close(pair[1]);
- m = magic_load(f, path, cflag || Wflag);
- if (cflag) {
- magic_dump(m);
- exit(0);
+ fclose(magicfp);
+ magicfp = NULL;
+
+ if (cflag)
+ goto wait_for_child;
+
+ imsg_init(&ibuf, pair[0]);
+ for (idx = 0; idx < argc; idx++) {
+ memset(&msg, 0, sizeof msg);
+ msg.idx = idx;
+
+ if (lstat(argv[idx], &msg.sb) == -1) {
+ fd = -1;
+ msg.error = errno;
+ } else {
+ fd = open(argv[idx], O_RDONLY|O_NONBLOCK);
+ if (fd == -1 && (errno == ENFILE || errno == EMFILE))
+ err(1, "open");
+ if (S_ISLNK(msg.sb.st_mode))
+ read_link(&msg, argv[idx]);
+ }
+ send_message(&ibuf, &msg, sizeof msg, fd);
+
+ if (read_message(&ibuf, &imsg, pid) == 0)
+ break;
+ if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof *ack)
+ errx(1, "message too small");
+ ack = imsg.data;
+ if (ack->idx != idx)
+ errx(1, "index not expected");
+ imsg_free(&imsg);
}
- files = xcalloc(argc, sizeof *files);
- for (i = 0; i < argc; i++)
- prepare_file(&files[i], argv[i], &width);
- for (i = 0; i < argc; i++) {
- open_file(&files[i]);
- test_file(m, &files[i], width);
+wait_for_child:
+ close(pair[0]);
+ while (wait(NULL) == -1 && errno != ECHILD) {
+ if (errno != EINTR)
+ err(1, "wait");
}
- exit(0);
+ _exit(0); /* let the child flush */
}
static void
-prepare_file(struct input_file *inf, const char *path, int *width)
+send_message(struct imsgbuf *ibuf, void *msg, size_t msglen, int fd)
{
- char *label;
- int n;
-
- inf->path = xstrdup(path);
-
- n = xasprintf(&label, "%s:", inf->path);
- if (n > *width)
- *width = n;
- inf->label = label;
+ if (imsg_compose(ibuf, -1, -1, 0, fd, msg, msglen) != 1)
+ err(1, "imsg_compose");
+ if (imsg_flush(ibuf) != 0)
+ err(1, "imsg_flush");
}
-static void
-open_file(struct input_file *inf)
+static int
+read_message(struct imsgbuf *ibuf, struct imsg *imsg, pid_t from)
{
- int retval;
+ int n;
- retval = lstat(inf->path, &inf->sb);
- if (retval == -1) {
- inf->error = strerror(errno);
- return;
- }
+ if ((n = imsg_read(ibuf)) == -1)
+ err(1, "imsg_read");
+ if (n == 0)
+ return (0);
+
+ if ((n = imsg_get(ibuf, imsg)) == -1)
+ err(1, "imsg_get");
+ if (n == 0)
+ return (0);
+
+ if ((pid_t)imsg->hdr.pid != from)
+ errx(1, "PIDs don't match");
+
+ return (n);
- if (S_ISLNK(inf->sb.st_mode))
- read_link(inf);
- inf->fd = open(inf->path, O_RDONLY|O_NONBLOCK);
}
static void
-read_link(struct input_file *inf)
+read_link(struct input_msg *msg, const char *path)
{
struct stat sb;
- char path[PATH_MAX];
+ char lpath[PATH_MAX];
char *copy, *root;
int used;
ssize_t size;
- size = readlink(inf->path, path, sizeof path);
+ size = readlink(path, lpath, sizeof lpath);
if (size == -1) {
- inf->link_error = strerror(errno);
+ msg->link_error = errno;
return;
}
- path[size] = '\0';
+ lpath[size] = '\0';
- if (*path == '/')
- strlcpy(inf->link_path, path, sizeof inf->link_path);
+ if (*lpath == '/')
+ strlcpy(msg->link_path, lpath, sizeof msg->link_path);
else {
- copy = xstrdup(inf->path);
+ copy = xstrdup(path);
root = dirname(copy);
if (*root == '\0' || strcmp(root, ".") == 0 ||
strcmp (root, "/") == 0)
- strlcpy(inf->link_path, path, sizeof inf->link_path);
+ strlcpy(msg->link_path, lpath, sizeof msg->link_path);
else {
- used = snprintf(inf->link_path, sizeof inf->link_path,
- "%s/%s", root, path);
- if (used < 0 || (size_t)used >= sizeof inf->link_path) {
- inf->link_error = strerror(ENAMETOOLONG);
+ used = snprintf(msg->link_path, sizeof msg->link_path,
+ "%s/%s", root, lpath);
+ if (used < 0 || (size_t)used >= sizeof msg->link_path) {
+ msg->link_error = ENAMETOOLONG;
return;
}
}
}
if (Lflag) {
- if (stat(inf->path, &inf->sb) == -1)
- inf->error = strerror(errno);
+ if (stat(path, &msg->sb) == -1)
+ msg->error = errno;
} else {
- if (stat(inf->path, &sb) == -1)
- inf->link_target = errno;
+ if (stat(path, &sb) == -1)
+ msg->link_target = errno;
}
}
+static __dead void
+child(int fd, pid_t parent, int argc, char **argv)
+{
+ struct magic *m;
+ struct imsgbuf ibuf;
+ struct imsg imsg;
+ struct input_msg *msg;
+ struct input_ack ack;
+ struct input_file inf;
+ int i, idx;
+ size_t len, width = 0;
+ struct passwd *pw;
+
+ if (geteuid() == 0) {
+ pw = getpwnam(FILE_USER);
+ if (pw == NULL)
+ errx(1, "unknown user %s", FILE_USER);
+ if (setgroups(1, &pw->pw_gid) != 0)
+ err(1, "setgroups");
+ if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0)
+ err(1, "setresgid");
+ if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0)
+ err(1, "setresuid");
+ }
+
+ m = magic_load(magicfp, magicpath, cflag || Wflag);
+ if (cflag) {
+ magic_dump(m);
+ exit(0);
+ }
+
+ for (i = 0; i < argc; i++) {
+ len = strlen(argv[i]) + 1;
+ if (len > width)
+ width = len;
+ }
+
+ imsg_init(&ibuf, fd);
+ for (;;) {
+ if (read_message(&ibuf, &imsg, parent) == 0)
+ break;
+ if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof *msg)
+ errx(1, "message too small");
+ msg = imsg.data;
+
+ idx = msg->idx;
+ if (idx < 0 || idx >= argc)
+ errx(1, "index out of range");
+
+ memset(&inf, 0, sizeof inf);
+ inf.m = m;
+ inf.msg = msg;
+
+ inf.path = argv[idx];
+ inf.fd = imsg.fd;
+
+ test_file(&inf, width);
+
+ if (imsg.fd != -1)
+ close(imsg.fd);
+ imsg_free(&imsg);
+
+ ack.idx = idx;
+ send_message(&ibuf, &ack, sizeof ack, -1);
+ }
+ exit(0);
+}
+
static void *
fill_buffer(struct input_file *inf)
{
static int
load_file(struct input_file *inf)
{
- inf->size = inf->sb.st_size;
+ inf->size = inf->msg->sb.st_size;
if (inf->size > FILE_READ_SIZE)
inf->size = FILE_READ_SIZE;
if (inf->size == 0) {
- if (!S_ISREG(inf->sb.st_mode))
+ if (!S_ISREG(inf->msg->sb.st_mode))
inf->size = FILE_READ_SIZE;
else
return (0);
static int
try_stat(struct input_file *inf)
{
- if (inf->error != NULL) {
+ if (inf->msg->error != 0) {
xasprintf(&inf->result, "cannot stat '%s' (%s)", inf->path,
- inf->error);
+ strerror(inf->msg->error));
return (1);
}
if (sflag) {
- switch (inf->sb.st_mode & S_IFMT) {
+ switch (inf->msg->sb.st_mode & S_IFMT) {
case S_IFBLK:
case S_IFCHR:
case S_IFREG:
}
}
- if (iflag && (inf->sb.st_mode & S_IFMT) != S_IFREG) {
+ if (iflag && (inf->msg->sb.st_mode & S_IFMT) != S_IFREG) {
xasprintf(&inf->result, "application/x-not-regular-file");
return (1);
}
-
- switch (inf->sb.st_mode & S_IFMT) {
+ switch (inf->msg->sb.st_mode & S_IFMT) {
case S_IFDIR:
xasprintf(&inf->result, "directory");
return (1);
case S_IFLNK:
- if (inf->link_error != NULL) {
+ if (inf->msg->link_error != 0) {
xasprintf(&inf->result, "unreadable symlink '%s' (%s)",
- inf->path, inf->link_error);
+ inf->path, strerror(inf->msg->link_error));
return (1);
}
- if (inf->link_target == ELOOP)
+ if (inf->msg->link_target == ELOOP)
xasprintf(&inf->result, "symbolic link in a loop");
- else if (inf->link_target != 0) {
+ else if (inf->msg->link_target != 0) {
xasprintf(&inf->result, "broken symbolic link to '%s'",
- inf->link_path);
+ inf->msg->link_path);
} else {
xasprintf(&inf->result, "symbolic link to '%s'",
- inf->link_path);
+ inf->msg->link_path);
}
return (1);
case S_IFSOCK:
return (1);
case S_IFBLK:
xasprintf(&inf->result, "block special (%ld/%ld)",
- (long)major(inf->sb.st_rdev), (long)minor(inf->sb.st_rdev));
+ (long)major(inf->msg->sb.st_rdev),
+ (long)minor(inf->msg->sb.st_rdev));
return (1);
case S_IFCHR:
xasprintf(&inf->result, "character special (%ld/%ld)",
- (long)major(inf->sb.st_rdev), (long)minor(inf->sb.st_rdev));
+ (long)major(inf->msg->sb.st_rdev),
+ (long)minor(inf->msg->sb.st_rdev));
return (1);
case S_IFIFO:
xasprintf(&inf->result, "fifo (named pipe)");
if (inf->fd != -1)
return (0);
- if (inf->sb.st_mode & (S_IWUSR|S_IWGRP|S_IWOTH))
+ if (inf->msg->sb.st_mode & (S_IWUSR|S_IWGRP|S_IWOTH))
strlcat(tmp, "writable, ", sizeof tmp);
- if (inf->sb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))
+ if (inf->msg->sb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))
strlcat(tmp, "executable, ", sizeof tmp);
- if (S_ISREG(inf->sb.st_mode))
+ if (S_ISREG(inf->msg->sb.st_mode))
strlcat(tmp, "regular file, ", sizeof tmp);
strlcat(tmp, "no read permission", sizeof tmp);
}
static void
-test_file(struct magic *m, struct input_file *inf, int width)
+test_file(struct input_file *inf, size_t width)
{
- int stop;
-
- inf->m = m;
+ char *label;
+ int stop;
stop = 0;
if (!stop)
if (bflag)
printf("%s\n", inf->result);
- else
- printf("%-*s %s\n", width, inf->label, inf->result);
+ else {
+ xasprintf(&label, "%s:", inf->path);
+ printf("%-*s %s\n", (int)width, label, inf->result);
+ free(label);
+ }
free(inf->result);
if (inf->mapped && inf->base != NULL)
munmap(inf->base, inf->size);
- inf->base = NULL;
-
- if (inf->fd != -1)
- close(inf->fd);
- free((void *)inf->label);
- free((void *)inf->path);
}
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