session: add support for saving and restoring session data to disk

This commit is contained in:
Jo-Philipp Wich 2013-09-04 15:18:14 +02:00
parent e0afdb10ae
commit aa2afdb739
2 changed files with 257 additions and 24 deletions

View file

@ -20,11 +20,19 @@
#ifndef __RPC_SESSION_H
#define __RPC_SESSION_H
#include <ctype.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <libubox/avl.h>
#include <libubox/blobmsg_json.h>
#define RPC_SID_LEN 32
#define RPC_DEFAULT_SESSION_TIMEOUT 300
#define RPC_SESSION_DIRECTORY "/var/run/rpcd"
struct rpc_session {
struct avl_node avl;
@ -68,4 +76,7 @@ struct rpc_session_cb {
void rpc_session_create_cb(struct rpc_session_cb *cb);
void rpc_session_destroy_cb(struct rpc_session_cb *cb);
void rpc_session_freeze(void);
void rpc_session_thaw(void);
#endif

270
session.c
View file

@ -84,6 +84,22 @@ static const struct blobmsg_policy perm_policy[__RPC_SP_MAX] = {
[RPC_SP_FUNCTION] = { .name = "function", .type = BLOBMSG_TYPE_STRING },
};
enum {
RPC_DUMP_SID,
RPC_DUMP_TIMEOUT,
RPC_DUMP_EXPIRES,
RPC_DUMP_ACLS,
RPC_DUMP_DATA,
__RPC_DUMP_MAX,
};
static const struct blobmsg_policy dump_policy[__RPC_DUMP_MAX] = {
[RPC_DUMP_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
[RPC_DUMP_TIMEOUT] = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
[RPC_DUMP_EXPIRES] = { .name = "expires", .type = BLOBMSG_TYPE_INT32 },
[RPC_DUMP_ACLS] = { .name = "acls", .type = BLOBMSG_TYPE_TABLE },
[RPC_DUMP_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
};
/*
* Keys in the AVL tree contain all pattern characters up to the first wildcard.
* To look up entries, start with the last entry that has a key less than or
@ -168,9 +184,7 @@ rpc_session_dump_acls(struct rpc_session *ses, struct blob_buf *b)
}
static void
rpc_session_dump(struct rpc_session *ses,
struct ubus_context *ctx,
struct ubus_request_data *req)
rpc_session_to_blob(struct rpc_session *ses)
{
void *c;
@ -187,6 +201,13 @@ rpc_session_dump(struct rpc_session *ses,
c = blobmsg_open_table(&buf, "data");
rpc_session_dump_data(ses, &buf);
blobmsg_close_table(&buf, c);
}
static void
rpc_session_dump(struct rpc_session *ses, struct ubus_context *ctx,
struct ubus_request_data *req)
{
rpc_session_to_blob(ses);
ubus_send_reply(ctx, req, buf.head);
}
@ -233,25 +254,43 @@ static void rpc_session_timeout(struct uloop_timeout *t)
rpc_session_destroy(ses);
}
static struct rpc_session *
rpc_session_new(void)
{
struct rpc_session *ses;
ses = calloc(1, sizeof(*ses));
if (!ses)
return NULL;
ses->avl.key = ses->id;
avl_init(&ses->acls, avl_strcmp, true, NULL);
avl_init(&ses->data, avl_strcmp, false, NULL);
ses->t.cb = rpc_session_timeout;
return ses;
}
static struct rpc_session *
rpc_session_create(int timeout)
{
struct rpc_session *ses;
struct rpc_session_cb *cb;
ses = calloc(1, sizeof(*ses));
ses = rpc_session_new();
if (!ses)
return NULL;
ses->timeout = timeout;
ses->avl.key = ses->id;
rpc_random(ses->id);
avl_insert(&sessions, &ses->avl);
avl_init(&ses->acls, avl_strcmp, true, NULL);
avl_init(&ses->data, avl_strcmp, false, NULL);
ses->timeout = timeout;
avl_insert(&sessions, &ses->avl);
ses->t.cb = rpc_session_timeout;
rpc_touch_session(ses);
list_for_each_entry(cb, &create_callbacks, list)
@ -540,13 +579,32 @@ rpc_handle_access(struct ubus_context *ctx, struct ubus_object *obj,
return 0;
}
static void
rpc_session_set(struct rpc_session *ses, const char *key, struct blob_attr *val)
{
struct rpc_session_data *data;
data = avl_find_element(&ses->data, key, data, avl);
if (data) {
avl_delete(&ses->data, &data->avl);
free(data);
}
data = calloc(1, sizeof(*data) + blob_pad_len(val));
if (!data)
return;
memcpy(data->attr, val, blob_pad_len(val));
data->avl.key = blobmsg_name(data->attr);
avl_insert(&ses->data, &data->avl);
}
static int
rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
struct ubus_request_data *req, const char *method,
struct blob_attr *msg)
{
struct rpc_session *ses;
struct rpc_session_data *data;
struct blob_attr *tb[__RPC_SA_MAX];
struct blob_attr *attr;
int rem;
@ -564,19 +622,7 @@ rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
if (!blobmsg_name(attr)[0])
continue;
data = avl_find_element(&ses->data, blobmsg_name(attr), data, avl);
if (data) {
avl_delete(&ses->data, &data->avl);
free(data);
}
data = calloc(1, sizeof(*data) + blob_pad_len(attr));
if (!data)
break;
memcpy(data->attr, attr, blob_pad_len(attr));
data->avl.key = blobmsg_name(data->attr);
avl_insert(&ses->data, &data->avl);
rpc_session_set(ses, blobmsg_name(attr), attr);
}
return 0;
@ -692,6 +738,134 @@ rpc_handle_destroy(struct ubus_context *ctx, struct ubus_object *obj,
return 0;
}
static bool
rpc_validate_sid(const char *id)
{
if (!id)
return false;
if (strlen(id) != RPC_SID_LEN)
return false;
while (*id)
if (!isxdigit(*id++))
return false;
return true;
}
static int
rpc_blob_to_file(const char *path, struct blob_attr *attr)
{
int fd, len;
fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
if (fd < 0)
return fd;
len = write(fd, attr, blob_pad_len(attr));
close(fd);
if (len != blob_pad_len(attr))
{
unlink(path);
return -1;
}
return len;
}
static struct blob_attr *
rpc_blob_from_file(const char *path)
{
int fd = -1, len;
struct stat s;
struct blob_attr head, *attr = NULL;
if (stat(path, &s) || !S_ISREG(s.st_mode))
return NULL;
fd = open(path, O_RDONLY);
if (fd < 0)
goto fail;
len = read(fd, &head, sizeof(head));
if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
goto fail;
attr = calloc(1, s.st_size);
if (!attr)
goto fail;
memcpy(attr, &head, sizeof(head));
len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
if (len != blob_pad_len(&head))
goto fail;
return attr;
fail:
if (fd >= 0)
close(fd);
if (attr)
free(attr);
return NULL;
}
static bool
rpc_session_from_blob(struct blob_attr *attr)
{
int i, rem, rem2, rem3;
struct rpc_session *ses;
struct blob_attr *tb[__RPC_DUMP_MAX], *scope, *object, *function;
blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
blob_data(attr), blob_len(attr));
for (i = 0; i < __RPC_DUMP_MAX; i++)
if (!tb[i])
return false;
ses = rpc_session_new();
if (!ses)
return false;
memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
blobmsg_for_each_attr(scope, tb[RPC_DUMP_ACLS], rem) {
blobmsg_for_each_attr(object, scope, rem2) {
blobmsg_for_each_attr(function, object, rem3) {
rpc_session_grant(ses, NULL, blobmsg_name(scope),
blobmsg_name(object),
blobmsg_data(function));
}
}
}
blobmsg_for_each_attr(object, tb[RPC_DUMP_DATA], rem) {
rpc_session_set(ses, blobmsg_name(object), object);
}
avl_insert(&sessions, &ses->avl);
uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
return true;
}
int rpc_session_api_init(struct ubus_context *ctx)
{
static const struct ubus_method session_methods[] = {
@ -743,3 +917,51 @@ void rpc_session_destroy_cb(struct rpc_session_cb *cb)
if (cb && cb->cb)
list_add(&cb->list, &destroy_callbacks);
}
void rpc_session_freeze(void)
{
struct stat s;
struct rpc_session *ses;
char path[PATH_MAX];
if (stat(RPC_SESSION_DIRECTORY, &s))
mkdir(RPC_SESSION_DIRECTORY, 0700);
avl_for_each_element(&sessions, ses, avl) {
snprintf(path, sizeof(path) - 1, RPC_SESSION_DIRECTORY "/%s", ses->id);
rpc_session_to_blob(ses);
rpc_blob_to_file(path, buf.head);
}
}
void rpc_session_thaw(void)
{
DIR *d;
char path[PATH_MAX];
struct dirent *e;
struct blob_attr *attr;
d = opendir(RPC_SESSION_DIRECTORY);
if (!d)
return;
while ((e = readdir(d)) != NULL) {
if (!rpc_validate_sid(e->d_name))
continue;
snprintf(path, sizeof(path) - 1,
RPC_SESSION_DIRECTORY "/%s", e->d_name);
attr = rpc_blob_from_file(path);
if (attr) {
rpc_session_from_blob(attr);
free(attr);
}
unlink(path);
}
closedir(d);
}