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Port ioctl recording to go through the main process
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Note that this changes the ioctl_tree_insert API to be more vala
friendly. i.e. it will return the new tree pointer, and it will always
take the passed tree node, free'ing it if a duplicate has been found.

This fixes storing the record if the process overrides SIGINT for
ioctl's.

Fixes martinpitt#96
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@martinpitt
Benjamin Berg authored and martinpitt committed Jun 1, 2021
1 parent 9738214 commit e4ea3a7
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Showing 8 changed files with 90 additions and 238 deletions.
11 changes: 8 additions & 3 deletions meson.build
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Original file line number Diff line number Diff line change
Expand Up @@ -158,9 +158,14 @@ umockdev_run_exe = executable('umockdev-run',
install: true)

umockdev_record_exe = executable('umockdev-record',
'src/umockdev-record.vala',
dependencies: [glib, gobject, gio, vapi_posix, vapi_config],
link_with: [umockdev_utils_lib, umockdev_lib],
['src/umockdev-record.vala',
'src/umockdev-ioctl.vala',
'src/ioctl_tree.vapi',
'src/ioctl_tree.c',
'src/debug.c'],
dependencies: [glib, gobject, gio_unix, vapi_posix, vapi_config, vapi_ioctl],
link_with: [umockdev_utils_lib],
include_directories: include_directories('src'),
install: true)

#
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11 changes: 6 additions & 5 deletions src/ioctl_tree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -129,8 +129,8 @@ ioctl_tree_last_sibling(ioctl_tree * node)
/**
* ioctl_tree_insert:
*
* If an equal node already exists, return that node and do not insert "node".
* Otherwise, insert it and return NULL.
* Insert the node and return the (new) root of the tree. If an equal node
* already exist, the node will not be inserted.
*/
ioctl_tree *
ioctl_tree_insert(ioctl_tree * tree, ioctl_tree * node)
Expand All @@ -143,7 +143,7 @@ ioctl_tree_insert(ioctl_tree * tree, ioctl_tree * node)
if (tree == NULL) {
node->last_added = ioctl_node_list_new();
ioctl_node_list_append(node->last_added, node);
return NULL;
return node;
}

/* trying to insert into itself? */
Expand All @@ -153,7 +153,8 @@ ioctl_tree_insert(ioctl_tree * tree, ioctl_tree * node)
if (existing) {
DBG(DBG_IOCTL_TREE, "ioctl_tree_insert: node of type %s ptr %p already exists\n", node->type->name, node);
ioctl_node_list_append(tree->last_added, existing);
return existing;
ioctl_tree_free(node);
return tree;
}

node->parent = node->type->insertion_parent(tree, node);
Expand All @@ -178,7 +179,7 @@ ioctl_tree_insert(ioctl_tree * tree, ioctl_tree * node)
}

ioctl_node_list_append(tree->last_added, node);
return NULL;
return tree;
}

ioctl_tree *
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2 changes: 1 addition & 1 deletion src/ioctl_tree.vapi
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ namespace IoctlTree {
public Tree.from_bin(ulong id, void *addr, int ret);

[ReturnsModifiedPointer]
public void insert(Tree node);
public void insert(owned Tree node);
public void* execute(void* last, ulong id, void* addr, ref int ret);
[CCode (instance_pos = -1)]
public void write(Posix.FILE f);
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212 changes: 25 additions & 187 deletions src/libumockdev-preload.c
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Original file line number Diff line number Diff line change
Expand Up @@ -422,167 +422,6 @@ netlink_recvmsg(int sockfd, struct msghdr * msg, int flags, ssize_t ret)
}


/********************************
*
* ioctl recording
*
********************************/

/* global state for recording ioctls */
int ioctl_record_fd = -1;
FILE *ioctl_record_log;
ioctl_tree *ioctl_record;
struct sigaction orig_actint;

static void ioctl_record_sigint_handler(int signum);

static void
ioctl_record_open(int fd)
{
libc_func(fopen, FILE*, const char *, const char*);
static dev_t record_rdev = (dev_t) - 1;

if (fd < 0)
return;

/* lazily initialize record_rdev */
if (record_rdev == (dev_t) - 1) {
const char *dev = getenv("UMOCKDEV_IOCTL_RECORD_DEV");

if (dev != NULL)
record_rdev = parse_dev_t(dev, "$UMOCKDEV_IOCTL_RECORD_DEV", 1);
else {
/* not recording */
record_rdev = 0;
}
}

if (record_rdev == 0)
return;

/* check if the opened device is the one we want to record */
if (dev_of_fd(fd) != record_rdev)
return;

/* recording is already in progress? */
if (ioctl_record_fd >= 0) {
/* libmtp opens the device multiple times, we can't do that */
/*
fprintf(stderr, "umockdev: recording for this device is already ongoing, stopping recording of previous open()\n");
ioctl_record_close();
*/
fprintf(stderr, "umockdev: WARNING: ioctl recording for this device is already ongoing on fd %i, but application opened it a second time on fd %i without closing\n", ioctl_record_fd, fd);
}

ioctl_record_fd = fd;

/* lazily open the record file */
if (ioctl_record_log == NULL) {
int r;

const char *path = getenv("UMOCKDEV_IOCTL_RECORD_FILE");
const char *device_path = getenv("UMOCKDEV_IOCTL_RECORD_DEVICE_PATH");
struct sigaction act_int;

if (path == NULL) {
fprintf(stderr, "umockdev: $UMOCKDEV_IOCTL_RECORD_FILE not set\n");
exit(1);
}
if (device_path == NULL) {
fprintf(stderr, "umockdev: $UMOCKDEV_IOCTL_RECORD_DEVICE_PATH not set\n");
exit(1);
}
ioctl_record_log = _fopen(path, "a+");
if (ioctl_record_log == NULL) {
perror("umockdev: failed to open ioctl record file");
exit(1);
}
/* We record the device node for later loading without specifying
* the devpath in umockdev_testbed_load_ioctl.
*/
fseek(ioctl_record_log, 0, SEEK_END);
if (ftell(ioctl_record_log) > 0) {
/* We're updating a previous log; don't write the devnode header again,
* but check that we're recording the same device as the previous log.
*/
char *existing_device_path;
char c;
DBG(DBG_IOCTL, "ioctl_record_open: Updating existing record for path %s\n", path);
fseek(ioctl_record_log, 0, SEEK_SET);

/* Start by skipping any leading comments */
while ((c = fgetc(ioctl_record_log)) == '#')
while (fgetc(ioctl_record_log) != '\n')
;
ungetc(c, ioctl_record_log);

if (fscanf(ioctl_record_log, "@DEV %ms\n", &existing_device_path) == 1)
{
/* We have an existing "@DEV /dev/something" directive, check it matches */
DBG(DBG_IOCTL, "ioctl_record_open: recording %s, existing device spec in record %s\n", device_path, existing_device_path);
if (strcmp(device_path, existing_device_path) != 0) {
fprintf(stderr, "umockdev: attempt to record two different devices to the same ioctl recording\n");
exit(1);
}
free(existing_device_path);
}

/* load an already existing log */
fseek(ioctl_record_log, 0, SEEK_SET);
ioctl_record = ioctl_tree_read(ioctl_record_log);
} else {
/* New log, add devnode header */
DBG(DBG_IOCTL, "ioctl_record_open: Starting new record %s\n", path);
fprintf(ioctl_record_log, "@DEV %s\n", device_path);
}

/* ensure that we write the file also on Control-C */
act_int.sa_handler = ioctl_record_sigint_handler;
r = sigemptyset(&act_int.sa_mask);
assert(r == 0);
act_int.sa_flags = 0;
r = sigaction(SIGINT, &act_int, &orig_actint);
assert(r == 0);

DBG(DBG_IOCTL, "ioctl_record_open: starting ioctl recording of fd %i into %s\n", fd, path);
} else {
DBG(DBG_IOCTL, "ioctl_record_open: ioctl recording is already ongoing, continuing on new fd %i\n", fd);
}
}

static void
ioctl_record_close(int fd)
{
if (fd < 0 || fd != ioctl_record_fd)
return;

DBG(DBG_IOCTL, "ioctl_record_close: stopping ioctl recording on fd %i\n", fd);
ioctl_record_fd = -1;

/* recorded anything? */
if (ioctl_record != NULL) {
int r;

rewind(ioctl_record_log);
r = ftruncate(fileno(ioctl_record_log), 0);
assert(r == 0);
fprintf(ioctl_record_log, "@DEV %s\n", getenv("UMOCKDEV_IOCTL_RECORD_DEVICE_PATH"));
ioctl_tree_write(ioctl_record_log, ioctl_record);
fflush(ioctl_record_log);
}
}

static void ioctl_record_sigint_handler(int signum)
{
int r;

DBG(DBG_IOCTL, "ioctl_record_sigint_handler: got signal %i, flushing record\n", signum);
ioctl_record_close(ioctl_record_fd);
r = sigaction(SIGINT, &orig_actint, NULL);
assert(r == 0);
raise(signum);
}

/********************************
*
* ioctl emulation
Expand All @@ -597,7 +436,7 @@ struct ioctl_fd_info {
};

static void
ioctl_emulate_open(int fd, const char *dev_path)
ioctl_emulate_open(int fd, const char *dev_path, int must_exist)
{
libc_func(socket, int, int, int, int);
libc_func(connect, int, int, const struct sockaddr *, socklen_t);
Expand All @@ -617,16 +456,24 @@ ioctl_emulate_open(int fd, const char *dev_path)

sock = _socket(AF_UNIX, SOCK_STREAM, 0);
if (sock == -1) {
fprintf(stderr, "ERROR: libumockdev-preload: Failed to open ioctl socket for %s",
dev_path);
exit(1);
if (must_exist) {
fprintf(stderr, "ERROR: libumockdev-preload: Failed to open ioctl socket for %s",
dev_path);
exit(1);
} else {
return;
}
}

ret = _connect(sock, (const struct sockaddr *) &addr, sizeof(addr));
if (ret == -1) {
fprintf(stderr, "ERROR: libumockdev-preload: Failed to connect to ioctl socket for %s",
dev_path);
exit(1);
if (must_exist) {
fprintf(stderr, "ERROR: libumockdev-preload: Failed to connect to ioctl socket for %s",
dev_path);
exit(1);
} else {
return;
}
}

fdinfo = malloc(sizeof(struct ioctl_fd_info));
Expand Down Expand Up @@ -685,8 +532,10 @@ ioctl_emulate(int fd, IOCTL_REQUEST_TYPE request, void *arg)
return UNHANDLED;
}

/* We force "unsigned int" here to prevent sign extension to long
* which could confuse the receiving side. */
req.cmd = IOCTL_REQ_IOCTL;
req.arg1 = (long) request;
req.arg1 = (unsigned int) request;
req.arg2 = (long) arg;

do {
Expand Down Expand Up @@ -1013,10 +862,9 @@ script_record_open(int fd)
static void
script_record_connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen, int res)
{
const char *path = getenv("UMOCKDEV_DIR");
size_t i;

if (addr->sa_family == AF_UNIX && res == 0 && path == NULL) {
if (addr->sa_family == AF_UNIX && res == 0) {
const char *sock_path = ((struct sockaddr_un *) addr)->sun_path;

/* find out where we log it to */
Expand Down Expand Up @@ -1372,12 +1220,9 @@ int prefix ## open ## suffix (const char *path, int flags, ...) \
} else \
ret = _ ## prefix ## open ## suffix(p, flags); \
TRAP_PATH_UNLOCK; \
if (path != p) \
ioctl_emulate_open(ret, path); \
else { \
ioctl_record_open(ret); \
ioctl_emulate_open(ret, path, path != p); \
if (path == p) \
script_record_open(ret); \
} \
return ret; \
}

Expand All @@ -1396,12 +1241,9 @@ int prefix ## open ## suffix (const char *path, int flags) \
DBG(DBG_PATH, "testbed wrapped " #prefix "open" #suffix "(%s) -> %s\n", path, p); \
ret = _ ## prefix ## open ## suffix(p, flags); \
TRAP_PATH_UNLOCK; \
if (path != p) \
ioctl_emulate_open(ret, path); \
else { \
ioctl_record_open(ret); \
ioctl_emulate_open(ret, path, path != p); \
if (path == p) \
script_record_open(ret); \
} \
return ret; \
}

Expand All @@ -1423,10 +1265,8 @@ FILE* prefix ## fopen ## suffix (const char *path, const char *mode) \
TRAP_PATH_UNLOCK; \
if (ret != NULL) { \
int fd = fileno(ret); \
if (path != p) \
ioctl_emulate_open(fd, path); \
else { \
ioctl_record_open(fd); \
ioctl_emulate_open(fd, path, path != p); \
if (path == p) { \
script_record_open(fd); \
} \
} \
Expand Down Expand Up @@ -1727,7 +1567,6 @@ close(int fd)

netlink_close(fd);
ioctl_emulate_close(fd);
ioctl_record_close(fd);
script_record_close(fd);

return _close(fd);
Expand All @@ -1741,7 +1580,6 @@ fclose(FILE * stream)
if (fd >= 0) {
netlink_close(fd);
ioctl_emulate_close(fd);
ioctl_record_close(fd);
script_record_close(fd);
}

Expand Down
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