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/*
* cgi-io - LuCI non-RPC helper
*
* Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <libubus.h>
#include <libubox/blobmsg.h>
#include "multipart_parser.h"
enum part {
PART_UNKNOWN,
PART_SESSIONID,
PART_FILENAME,
PART_FILEMODE,
PART_FILEDATA
};
const char *parts[] = {
"(bug)",
"sessionid",
"filename",
"filemode",
"filedata",
};
struct state
{
bool is_content_disposition;
enum part parttype;
char *sessionid;
char *filename;
bool filedata;
int filemode;
int filefd;
int tempfd;
};
enum {
SES_ACCESS,
__SES_MAX,
};
static const struct blobmsg_policy ses_policy[__SES_MAX] = {
[SES_ACCESS] = { .name = "access", .type = BLOBMSG_TYPE_BOOL },
};
static struct state st;
static void
session_access_cb(struct ubus_request *req, int type, struct blob_attr *msg)
{
struct blob_attr *tb[__SES_MAX];
bool *allow = (bool *)req->priv;
if (!msg)
return;
blobmsg_parse(ses_policy, __SES_MAX, tb, blob_data(msg), blob_len(msg));
if (tb[SES_ACCESS])
*allow = blobmsg_get_bool(tb[SES_ACCESS]);
}
static bool
session_access(const char *sid, const char *obj, const char *func)
{
uint32_t id;
bool allow = false;
struct ubus_context *ctx;
static struct blob_buf req;
ctx = ubus_connect(NULL);
if (!ctx || ubus_lookup_id(ctx, "session", &id))
goto out;
blob_buf_init(&req, 0);
blobmsg_add_string(&req, "ubus_rpc_session", sid);
blobmsg_add_string(&req, "scope", "cgi-io");
blobmsg_add_string(&req, "object", obj);
blobmsg_add_string(&req, "function", func);
ubus_invoke(ctx, id, "access", req.head, session_access_cb, &allow, 500);
out:
if (ctx)
ubus_free(ctx);
return allow;
}
static char *
checksum(const char *applet, size_t sumlen, const char *file)
{
pid_t pid;
int fds[2];
static char chksum[65];
if (pipe(fds))
return NULL;
switch ((pid = fork()))
{
case -1:
return NULL;
case 0:
uloop_done();
dup2(fds[1], 1);
close(0);
close(2);
close(fds[0]);
close(fds[1]);
if (execl("/bin/busybox", "/bin/busybox", applet, file, NULL))
return NULL;
break;
default:
memset(chksum, 0, sizeof(chksum));
read(fds[0], chksum, sumlen);
waitpid(pid, NULL, 0);
close(fds[0]);
close(fds[1]);
}
return chksum;
}
static char *
datadup(const void *in, size_t len)
{
char *out = malloc(len + 1);
if (!out)
return NULL;
memcpy(out, in, len);
*(out + len) = 0;
return out;
}
static bool
urldecode(char *buf)
{
char *c, *p;
if (!buf || !*buf)
return true;
#define hex(x) \
(((x) <= '9') ? ((x) - '0') : \
(((x) <= 'F') ? ((x) - 'A' + 10) : \
((x) - 'a' + 10)))
for (c = p = buf; *p; c++)
{
if (*p == '%')
{
if (!isxdigit(*(p + 1)) || !isxdigit(*(p + 2)))
return false;
*c = (char)(16 * hex(*(p + 1)) + hex(*(p + 2)));
p += 3;
}
else if (*p == '+')
{
*c = ' ';
p++;
}
else
{
*c = *p++;
}
}
*c = 0;
return true;
}
static bool
postdecode(char **fields, int n_fields)
{
char *p;
const char *var;
static char buf[1024];
int i, len, field, found = 0;
var = getenv("CONTENT_TYPE");
if (!var || strncmp(var, "application/x-www-form-urlencoded", 33))
return false;
memset(buf, 0, sizeof(buf));
if ((len = read(0, buf, sizeof(buf) - 1)) > 0)
{
for (p = buf, i = 0; i <= len; i++)
{
if (buf[i] == '=')
{
buf[i] = 0;
for (field = 0; field < (n_fields * 2); field += 2)
{
if (!strcmp(p, fields[field]))
{
fields[field + 1] = buf + i + 1;
found++;
}
}
}
else if (buf[i] == '&' || buf[i] == '\0')
{
buf[i] = 0;
if (found >= n_fields)
break;
p = buf + i + 1;
}
}
}
for (field = 0; field < (n_fields * 2); field += 2)
if (!urldecode(fields[field + 1]))
return false;
return (found >= n_fields);
}
static int
response(bool success, const char *message)
{
char *chksum;
struct stat s;
printf("Status: 200 OK\r\n");
printf("Content-Type: text/plain\r\n\r\n{\n");
if (success)
{
if (!stat(st.filename, &s))
printf("\t\"size\": %u,\n", (unsigned int)s.st_size);
else
printf("\t\"size\": null,\n");
chksum = checksum("md5sum", 32, st.filename);
printf("\t\"checksum\": %s%s%s,\n",
chksum ? "\"" : "",
chksum ? chksum : "null",
chksum ? "\"" : "");
chksum = checksum("sha256sum", 64, st.filename);
printf("\t\"sha256sum\": %s%s%s\n",
chksum ? "\"" : "",
chksum ? chksum : "null",
chksum ? "\"" : "");
}
else
{
if (message)
printf("\t\"message\": \"%s\",\n", message);
printf("\t\"failure\": [ %u, \"%s\" ]\n", errno, strerror(errno));
if (st.filefd > -1)
unlink(st.filename);
}
printf("}\n");
return -1;
}
static int
failure(int e, const char *message)
{
printf("Status: 500 Internal Server failure\r\n");
printf("Content-Type: text/plain\r\n\r\n");
printf("%s", message);
if (e)
printf(": %s", strerror(e));
return -1;
}
static int
filecopy(void)
{
int len;
char buf[4096];
if (!st.filedata)
{
close(st.tempfd);
errno = EINVAL;
return response(false, "No file data received");
}
if (lseek(st.tempfd, 0, SEEK_SET) < 0)
{
close(st.tempfd);
return response(false, "Failed to rewind temp file");
}
st.filefd = open(st.filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (st.filefd < 0)
{
close(st.tempfd);
return response(false, "Failed to open target file");
}
while ((len = read(st.tempfd, buf, sizeof(buf))) > 0)
{
if (write(st.filefd, buf, len) != len)
{
close(st.tempfd);
close(st.filefd);
return response(false, "I/O failure while writing target file");
}
}
close(st.tempfd);
close(st.filefd);
if (chmod(st.filename, st.filemode))
return response(false, "Failed to chmod target file");
return 0;
}
static int
header_field(multipart_parser *p, const char *data, size_t len)
{
st.is_content_disposition = !strncasecmp(data, "Content-Disposition", len);
return 0;
}
static int
header_value(multipart_parser *p, const char *data, size_t len)
{
int i, j;
if (!st.is_content_disposition)
return 0;
if (len < 10 || strncasecmp(data, "form-data", 9))
return 0;
for (data += 9, len -= 9; *data == ' ' || *data == ';'; data++, len--);
if (len < 8 || strncasecmp(data, "name=\"", 6))
return 0;
for (data += 6, len -= 6, i = 0; i <= len; i++)
{
if (*(data + i) != '"')
continue;
for (j = 1; j < sizeof(parts) / sizeof(parts[0]); j++)
if (!strncmp(data, parts[j], i))
st.parttype = j;
break;
}
return 0;
}
static int
data_begin_cb(multipart_parser *p)
{
char tmpname[24] = "/tmp/luci-upload.XXXXXX";
if (st.parttype == PART_FILEDATA)
{
if (!st.sessionid)
return response(false, "File data without session");
if (!st.filename)
return response(false, "File data without name");
st.tempfd = mkstemp(tmpname);
if (st.tempfd < 0)
return response(false, "Failed to create temporary file");
unlink(tmpname);
}
return 0;
}
static int
data_cb(multipart_parser *p, const char *data, size_t len)
{
switch (st.parttype)
{
case PART_SESSIONID:
st.sessionid = datadup(data, len);
break;
case PART_FILENAME:
st.filename = datadup(data, len);
break;
case PART_FILEMODE:
st.filemode = strtoul(data, NULL, 8);
break;
case PART_FILEDATA:
if (write(st.tempfd, data, len) != len)
{
close(st.tempfd);
return response(false, "I/O failure while writing temporary file");
}
if (!st.filedata)
st.filedata = !!len;
break;
default:
break;
}
return 0;
}
static int
data_end_cb(multipart_parser *p)
{
if (st.parttype == PART_SESSIONID)
{
if (!session_access(st.sessionid, "upload", "write"))
{
errno = EPERM;
return response(false, "Upload permission denied");
}
}
else if (st.parttype == PART_FILEDATA)
{
if (st.tempfd < 0)
return response(false, "Internal program failure");
#if 0
/* prepare directory */
for (ptr = st.filename; *ptr; ptr++)
{
if (*ptr == '/')
{
*ptr = 0;
if (mkdir(st.filename, 0755))
{
unlink(st.tmpname);
return response(false, "Failed to create destination directory");
}
*ptr = '/';
}
}
#endif
if (filecopy())
return -1;
return response(true, NULL);
}
st.parttype = PART_UNKNOWN;
return 0;
}
static multipart_parser *
init_parser(void)
{
char *boundary;
const char *var;
multipart_parser *p;
static multipart_parser_settings s = {
.on_part_data = data_cb,
.on_headers_complete = data_begin_cb,
.on_part_data_end = data_end_cb,
.on_header_field = header_field,
.on_header_value = header_value
};
var = getenv("CONTENT_TYPE");
if (!var || strncmp(var, "multipart/form-data;", 20))
return NULL;
for (var += 20; *var && *var != '='; var++);
if (*var++ != '=')
return NULL;
boundary = malloc(strlen(var) + 3);
if (!boundary)
return NULL;
strcpy(boundary, "--");
strcpy(boundary + 2, var);
st.tempfd = -1;
st.filefd = -1;
st.filemode = 0600;
p = multipart_parser_init(boundary, &s);
free(boundary);
return p;
}
static int
main_upload(int argc, char *argv[])
{
int rem, len;
char buf[4096];
multipart_parser *p;
p = init_parser();
if (!p)
{
errno = EINVAL;
return response(false, "Invalid request");
}
while ((len = read(0, buf, sizeof(buf))) > 0)
{
rem = multipart_parser_execute(p, buf, len);
if (rem < len)
break;
}
multipart_parser_free(p);
/* read remaining post data */
while ((len = read(0, buf, sizeof(buf))) > 0);
return 0;
}
static int
main_backup(int argc, char **argv)
{
pid_t pid;
time_t now;
int len;
int status;
int fds[2];
char buf[4096];
char datestr[16] = { 0 };
char hostname[64] = { 0 };
char *fields[] = { "sessionid", NULL };
if (!postdecode(fields, 1) || !session_access(fields[1], "backup", "read"))
return failure(0, "Backup permission denied");
if (pipe(fds))
return failure(errno, "Failed to spawn pipe");
switch ((pid = fork()))
{
case -1:
return failure(errno, "Failed to fork process");
case 0:
dup2(fds[1], 1);
close(0);
close(2);
close(fds[0]);
close(fds[1]);
chdir("/");
execl("/sbin/sysupgrade", "/sbin/sysupgrade",
"--create-backup", "-", NULL);
return -1;
default:
fcntl(fds[0], F_SETFL, fcntl(fds[0], F_GETFL) | O_NONBLOCK);
now = time(NULL);
strftime(datestr, sizeof(datestr) - 1, "%Y-%m-%d", localtime(&now));
if (gethostname(hostname, sizeof(hostname) - 1))
sprintf(hostname, "OpenWrt");
printf("Status: 200 OK\r\n");
printf("Content-Type: application/x-targz\r\n");
printf("Content-Disposition: attachment; "
"filename=\"backup-%s-%s.tar.gz\"\r\n\r\n", hostname, datestr);
do {
waitpid(pid, &status, 0);
while ((len = read(fds[0], buf, sizeof(buf))) > 0) {
fwrite(buf, len, 1, stdout);
fflush(stdout);
}
} while (!WIFEXITED(status));
close(fds[0]);
close(fds[1]);
return 0;
}
}
int main(int argc, char **argv)
{
if (strstr(argv[0], "cgi-upload"))
return main_upload(argc, argv);
else if (strstr(argv[0], "cgi-backup"))
return main_backup(argc, argv);
return -1;
}