--- /dev/null
+/*
+ * 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.
+ */
+
+#define _GNU_SOURCE /* splice(), SPLICE_F_MORE */
+
+#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 <sys/sendfile.h>
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+
+#include <libubus.h>
+#include <libubox/blobmsg.h>
+
+#include "multipart_parser.h"
+
+#define READ_BLOCK 4096
+
+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 *scope, 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", scope);
+ 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 r;
+ 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));
+ r = read(fds[0], chksum, sumlen);
+
+ waitpid(pid, NULL, 0);
+ close(fds[0]);
+ close(fds[1]);
+
+ if (r < 0)
+ return NULL;
+ }
+
+ 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 char *
+canonicalize_path(const char *path, size_t len)
+{
+ char *canonpath, *cp;
+ const char *p, *e;
+
+ if (path == NULL || *path == '\0')
+ return NULL;
+
+ canonpath = datadup(path, len);
+
+ if (canonpath == NULL)
+ return NULL;
+
+ /* normalize */
+ for (cp = canonpath, p = path, e = path + len; p < e; ) {
+ if (*p != '/')
+ goto next;
+
+ /* skip repeating / */
+ if ((p + 1 < e) && (p[1] == '/')) {
+ p++;
+ continue;
+ }
+
+ /* /./ or /../ */
+ if ((p + 1 < e) && (p[1] == '.')) {
+ /* skip /./ */
+ if ((p + 2 >= e) || (p[2] == '/')) {
+ p += 2;
+ continue;
+ }
+
+ /* collapse /x/../ */
+ if ((p + 2 < e) && (p[2] == '.') && ((p + 3 >= e) || (p[3] == '/'))) {
+ while ((cp > canonpath) && (*--cp != '/'))
+ ;
+
+ p += 3;
+ continue;
+ }
+ }
+
+next:
+ *cp++ = *p++;
+ }
+
+ /* remove trailing slash if not root / */
+ if ((cp > canonpath + 1) && (cp[-1] == '/'))
+ cp--;
+ else if (cp == canonpath)
+ *cp++ = '/';
+
+ *cp = '\0';
+
+ return canonpath;
+}
+
+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 code, int e, const char *message)
+{
+ printf("Status: %d %s\r\n", code, message);
+ printf("Content-Type: text/plain\r\n\r\n");
+ printf("%s", message);
+
+ if (e)
+ printf(": %s", strerror(e));
+
+ printf("\n");
+
+ return -1;
+}
+
+static int
+filecopy(void)
+{
+ int len;
+ char buf[READ_BLOCK];
+
+ 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)
+{
+ size_t 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");
+
+ if (!session_access(st.sessionid, "file", st.filename, "write"))
+ return response(false, "Access to path denied by ACL");
+
+ 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)
+{
+ int wlen = len;
+
+ switch (st.parttype)
+ {
+ case PART_SESSIONID:
+ st.sessionid = datadup(data, len);
+ break;
+
+ case PART_FILENAME:
+ st.filename = canonicalize_path(data, len);
+ break;
+
+ case PART_FILEMODE:
+ st.filemode = strtoul(data, NULL, 8);
+ break;
+
+ case PART_FILEDATA:
+ if (write(st.tempfd, data, len) != wlen)
+ {
+ close(st.tempfd);
+ return response(false, "I/O failure while writing temporary file");
+ }
+
+ if (!st.filedata)
+ st.filedata = !!wlen;
+
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int
+data_end_cb(multipart_parser *p)
+{
+ if (st.parttype == PART_SESSIONID)
+ {
+ if (!session_access(st.sessionid, "cgi-io", "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;
+ bool done = false;
+ char buf[READ_BLOCK];
+ multipart_parser *p;
+
+ p = init_parser();
+
+ if (!p)
+ {
+ errno = EINVAL;
+ return response(false, "Invalid request");
+ }
+
+ while ((len = read(0, buf, sizeof(buf))) > 0)
+ {
+ if (!done) {
+ rem = multipart_parser_execute(p, buf, len);
+ done = (rem < len);
+ }
+ }
+
+ multipart_parser_free(p);
+
+ return 0;
+}
+
+static int
+main_download(int argc, char **argv)
+{
+ char *fields[] = { "sessionid", NULL, "path", NULL, "filename", NULL, "mimetype", NULL };
+ unsigned long long size = 0;
+ char *p, buf[READ_BLOCK];
+ ssize_t len = 0;
+ struct stat s;
+ int rfd;
+
+ postdecode(fields, 4);
+
+ if (!fields[1] || !session_access(fields[1], "cgi-io", "download", "read"))
+ return failure(403, 0, "Download permission denied");
+
+ if (!fields[3] || !session_access(fields[1], "file", fields[3], "read"))
+ return failure(403, 0, "Access to path denied by ACL");
+
+ if (stat(fields[3], &s))
+ return failure(404, errno, "Failed to stat requested path");
+
+ if (!S_ISREG(s.st_mode) && !S_ISBLK(s.st_mode))
+ return failure(403, 0, "Requested path is not a regular file or block device");
+
+ for (p = fields[5]; p && *p; p++)
+ if (!isalnum(*p) && !strchr(" ()<>@,;:[]?.=%-", *p))
+ return failure(400, 0, "Invalid characters in filename");
+
+ for (p = fields[7]; p && *p; p++)
+ if (!isalnum(*p) && !strchr(" .;=/-", *p))
+ return failure(400, 0, "Invalid characters in mimetype");
+
+ rfd = open(fields[3], O_RDONLY);
+
+ if (rfd < 0)
+ return failure(500, errno, "Failed to open requested path");
+
+ if (S_ISBLK(s.st_mode))
+ ioctl(rfd, BLKGETSIZE64, &size);
+ else
+ size = (unsigned long long)s.st_size;
+
+ printf("Status: 200 OK\r\n");
+ printf("Content-Type: %s\r\n", fields[7] ? fields[7] : "application/octet-stream");
+
+ if (fields[5])
+ printf("Content-Disposition: attachment; filename=\"%s\"\r\n", fields[5]);
+
+ printf("Content-Length: %llu\r\n\r\n", size);
+ fflush(stdout);
+
+ while (size > 0) {
+ len = sendfile(1, rfd, NULL, size);
+
+ if (len == -1) {
+ if (errno == ENOSYS || errno == EINVAL) {
+ while ((len = read(rfd, buf, sizeof(buf))) > 0)
+ fwrite(buf, len, 1, stdout);
+
+ fflush(stdout);
+ break;
+ }
+
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ }
+
+ if (len <= 0)
+ break;
+
+ size -= len;
+ }
+
+ close(rfd);
+
+ return 0;
+}
+
+static int
+main_backup(int argc, char **argv)
+{
+ pid_t pid;
+ time_t now;
+ int r;
+ int len;
+ int status;
+ int fds[2];
+ char datestr[16] = { 0 };
+ char hostname[64] = { 0 };
+ char *fields[] = { "sessionid", NULL };
+
+ if (!postdecode(fields, 1) || !session_access(fields[1], "cgi-io", "backup", "read"))
+ return failure(403, 0, "Backup permission denied");
+
+ if (pipe(fds))
+ return failure(500, errno, "Failed to spawn pipe");
+
+ switch ((pid = fork()))
+ {
+ case -1:
+ return failure(500, errno, "Failed to fork process");
+
+ case 0:
+ dup2(fds[1], 1);
+
+ close(0);
+ close(2);
+ close(fds[0]);
+ close(fds[1]);
+
+ r = chdir("/");
+ if (r < 0)
+ return failure(500, errno, "Failed chdir('/')");
+
+ execl("/sbin/sysupgrade", "/sbin/sysupgrade",
+ "--create-backup", "-", NULL);
+
+ return -1;
+
+ default:
+ close(fds[1]);
+
+ 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);
+
+ fflush(stdout);
+
+ do {
+ len = splice(fds[0], NULL, 1, NULL, READ_BLOCK, SPLICE_F_MORE);
+ } while (len > 0);
+
+ waitpid(pid, &status, 0);
+
+ close(fds[0]);
+
+ return 0;
+ }
+}
+
+
+static const char *
+lookup_executable(const char *cmd)
+{
+ size_t plen = 0, clen = strlen(cmd) + 1;
+ static char path[PATH_MAX];
+ char *search, *p;
+ struct stat s;
+
+ if (!stat(cmd, &s) && S_ISREG(s.st_mode))
+ return cmd;
+
+ search = getenv("PATH");
+
+ if (!search)
+ search = "/bin:/usr/bin:/sbin:/usr/sbin";
+
+ p = search;
+
+ do {
+ if (*p != ':' && *p != '\0')
+ continue;
+
+ plen = p - search;
+
+ if ((plen + clen) >= sizeof(path))
+ continue;
+
+ strncpy(path, search, plen);
+ sprintf(path + plen, "/%s", cmd);
+
+ if (!stat(path, &s) && S_ISREG(s.st_mode))
+ return path;
+
+ search = p + 1;
+ } while (*p++);
+
+ return NULL;
+}
+
+static char **
+parse_command(const char *cmdline)
+{
+ const char *p = cmdline, *s;
+ char **argv = NULL, *out;
+ size_t arglen = 0;
+ int argnum = 0;
+ bool esc;
+
+ while (isspace(*cmdline))
+ cmdline++;
+
+ for (p = cmdline, s = p, esc = false; p; p++) {
+ if (esc) {
+ esc = false;
+ }
+ else if (*p == '\\' && p[1] != 0) {
+ esc = true;
+ }
+ else if (isspace(*p) || *p == 0) {
+ if (p > s) {
+ argnum += 1;
+ arglen += sizeof(char *) + (p - s) + 1;
+ }
+
+ s = p + 1;
+ }
+
+ if (*p == 0)
+ break;
+ }
+
+ if (arglen == 0)
+ return NULL;
+
+ argv = calloc(1, arglen + sizeof(char *));
+
+ if (!argv)
+ return NULL;
+
+ out = (char *)argv + sizeof(char *) * (argnum + 1);
+ argv[0] = out;
+
+ for (p = cmdline, s = p, esc = false, argnum = 0; p; p++) {
+ if (esc) {
+ esc = false;
+ *out++ = *p;
+ }
+ else if (*p == '\\' && p[1] != 0) {
+ esc = true;
+ }
+ else if (isspace(*p) || *p == 0) {
+ if (p > s) {
+ *out++ = ' ';
+ argv[++argnum] = out;
+ }
+
+ s = p + 1;
+ }
+ else {
+ *out++ = *p;
+ }
+
+ if (*p == 0)
+ break;
+ }
+
+ argv[argnum] = NULL;
+ out[-1] = 0;
+
+ return argv;
+}
+
+static int
+main_exec(int argc, char **argv)
+{
+ char *fields[] = { "sessionid", NULL, "command", NULL, "filename", NULL, "mimetype", NULL };
+ int i, devnull, status, fds[2];
+ bool allowed = false;
+ ssize_t len = 0;
+ const char *exe;
+ char *p, **args;
+ pid_t pid;
+
+ postdecode(fields, 4);
+
+ if (!fields[1] || !session_access(fields[1], "cgi-io", "exec", "read"))
+ return failure(403, 0, "Exec permission denied");
+
+ for (p = fields[5]; p && *p; p++)
+ if (!isalnum(*p) && !strchr(" ()<>@,;:[]?.=%-", *p))
+ return failure(400, 0, "Invalid characters in filename");
+
+ for (p = fields[7]; p && *p; p++)
+ if (!isalnum(*p) && !strchr(" .;=/-", *p))
+ return failure(400, 0, "Invalid characters in mimetype");
+
+ args = fields[3] ? parse_command(fields[3]) : NULL;
+
+ if (!args)
+ return failure(400, 0, "Invalid command parameter");
+
+ /* First check if we find an ACL match for the whole cmdline ... */
+ allowed = session_access(fields[1], "file", args[0], "exec");
+
+ /* Now split the command vector... */
+ for (i = 1; args[i]; i++)
+ args[i][-1] = 0;
+
+ /* Find executable... */
+ exe = lookup_executable(args[0]);
+
+ if (!exe) {
+ free(args);
+ return failure(404, 0, "Executable not found");
+ }
+
+ /* If there was no ACL match, check for a match on the executable */
+ if (!allowed && !session_access(fields[1], "file", exe, "exec")) {
+ free(args);
+ return failure(403, 0, "Access to command denied by ACL");
+ }
+
+ if (pipe(fds)) {
+ free(args);
+ return failure(500, errno, "Failed to spawn pipe");
+ }
+
+ switch ((pid = fork()))
+ {
+ case -1:
+ free(args);
+ close(fds[0]);
+ close(fds[1]);
+ return failure(500, errno, "Failed to fork process");
+
+ case 0:
+ devnull = open("/dev/null", O_RDWR);
+
+ if (devnull > -1) {
+ dup2(devnull, 0);
+ dup2(devnull, 2);
+ close(devnull);
+ }
+ else {
+ close(0);
+ close(2);
+ }
+
+ dup2(fds[1], 1);
+ close(fds[0]);
+ close(fds[1]);
+
+ if (chdir("/") < 0) {
+ free(args);
+ return failure(500, errno, "Failed chdir('/')");
+ }
+
+ if (execv(exe, args) < 0) {
+ free(args);
+ return failure(500, errno, "Failed execv(...)");
+ }
+
+ return -1;
+
+ default:
+ close(fds[1]);
+
+ printf("Status: 200 OK\r\n");
+ printf("Content-Type: %s\r\n",
+ fields[7] ? fields[7] : "application/octet-stream");
+
+ if (fields[5])
+ printf("Content-Disposition: attachment; filename=\"%s\"\r\n",
+ fields[5]);
+
+ printf("\r\n");
+ fflush(stdout);
+
+ do {
+ len = splice(fds[0], NULL, 1, NULL, READ_BLOCK, SPLICE_F_MORE);
+ } while (len > 0);
+
+ waitpid(pid, &status, 0);
+
+ close(fds[0]);
+ free(args);
+
+ 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-download"))
+ return main_download(argc, argv);
+ else if (strstr(argv[0], "cgi-backup"))
+ return main_backup(argc, argv);
+ else if (strstr(argv[0], "cgi-exec"))
+ return main_exec(argc, argv);
+
+ return -1;
+}
--- /dev/null
+/* Based on node-formidable by Felix Geisendörfer
+ * Igor Afonov - afonov@gmail.com - 2012
+ * MIT License - http://www.opensource.org/licenses/mit-license.php
+ */
+
+#include "multipart_parser.h"
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+
+static void multipart_log(const char * format, ...)
+{
+#ifdef DEBUG_MULTIPART
+ va_list args;
+ va_start(args, format);
+
+ fprintf(stderr, "[HTTP_MULTIPART_PARSER] %s:%d: ", __FILE__, __LINE__);
+ vfprintf(stderr, format, args);
+ fprintf(stderr, "\n");
+#endif
+}
+
+#define NOTIFY_CB(FOR) \
+do { \
+ if (p->settings->on_##FOR) { \
+ if (p->settings->on_##FOR(p) != 0) { \
+ return i; \
+ } \
+ } \
+} while (0)
+
+#define EMIT_DATA_CB(FOR, ptr, len) \
+do { \
+ if (p->settings->on_##FOR) { \
+ if (p->settings->on_##FOR(p, ptr, len) != 0) { \
+ return i; \
+ } \
+ } \
+} while (0)
+
+
+#define LF 10
+#define CR 13
+
+struct multipart_parser {
+ void * data;
+
+ size_t index;
+ size_t boundary_length;
+
+ unsigned char state;
+
+ const multipart_parser_settings* settings;
+
+ char* lookbehind;
+ char multipart_boundary[1];
+};
+
+enum state {
+ s_uninitialized = 1,
+ s_start,
+ s_start_boundary,
+ s_header_field_start,
+ s_header_field,
+ s_headers_almost_done,
+ s_header_value_start,
+ s_header_value,
+ s_header_value_almost_done,
+ s_part_data_start,
+ s_part_data,
+ s_part_data_almost_boundary,
+ s_part_data_boundary,
+ s_part_data_almost_end,
+ s_part_data_end,
+ s_part_data_final_hyphen,
+ s_end
+};
+
+multipart_parser* multipart_parser_init
+ (const char *boundary, const multipart_parser_settings* settings) {
+
+ multipart_parser* p = malloc(sizeof(multipart_parser) +
+ strlen(boundary) +
+ strlen(boundary) + 9);
+
+ strcpy(p->multipart_boundary, boundary);
+ p->boundary_length = strlen(boundary);
+
+ p->lookbehind = (p->multipart_boundary + p->boundary_length + 1);
+
+ p->index = 0;
+ p->state = s_start;
+ p->settings = settings;
+
+ return p;
+}
+
+void multipart_parser_free(multipart_parser* p) {
+ free(p);
+}
+
+void multipart_parser_set_data(multipart_parser *p, void *data) {
+ p->data = data;
+}
+
+void *multipart_parser_get_data(multipart_parser *p) {
+ return p->data;
+}
+
+size_t multipart_parser_execute(multipart_parser* p, const char *buf, size_t len) {
+ size_t i = 0;
+ size_t mark = 0;
+ char c, cl;
+ int is_last = 0;
+
+ while(i < len) {
+ c = buf[i];
+ is_last = (i == (len - 1));
+ switch (p->state) {
+ case s_start:
+ multipart_log("s_start");
+ p->index = 0;
+ p->state = s_start_boundary;
+
+ /* fallthrough */
+ case s_start_boundary:
+ multipart_log("s_start_boundary");
+ if (p->index == p->boundary_length) {
+ if (c != CR) {
+ return i;
+ }
+ p->index++;
+ break;
+ } else if (p->index == (p->boundary_length + 1)) {
+ if (c != LF) {
+ return i;
+ }
+ p->index = 0;
+ NOTIFY_CB(part_data_begin);
+ p->state = s_header_field_start;
+ break;
+ }
+ if (c != p->multipart_boundary[p->index]) {
+ return i;
+ }
+ p->index++;
+ break;
+
+ case s_header_field_start:
+ multipart_log("s_header_field_start");
+ mark = i;
+ p->state = s_header_field;
+
+ /* fallthrough */
+ case s_header_field:
+ multipart_log("s_header_field");
+ if (c == CR) {
+ p->state = s_headers_almost_done;
+ break;
+ }
+
+ if (c == '-') {
+ break;
+ }
+
+ if (c == ':') {
+ EMIT_DATA_CB(header_field, buf + mark, i - mark);
+ p->state = s_header_value_start;
+ break;
+ }
+
+ cl = tolower(c);
+ if (cl < 'a' || cl > 'z') {
+ multipart_log("invalid character in header name");
+ return i;
+ }
+ if (is_last)
+ EMIT_DATA_CB(header_field, buf + mark, (i - mark) + 1);
+ break;
+
+ case s_headers_almost_done:
+ multipart_log("s_headers_almost_done");
+ if (c != LF) {
+ return i;
+ }
+
+ p->state = s_part_data_start;
+ break;
+
+ case s_header_value_start:
+ multipart_log("s_header_value_start");
+ if (c == ' ') {
+ break;
+ }
+
+ mark = i;
+ p->state = s_header_value;
+
+ /* fallthrough */
+ case s_header_value:
+ multipart_log("s_header_value");
+ if (c == CR) {
+ EMIT_DATA_CB(header_value, buf + mark, i - mark);
+ p->state = s_header_value_almost_done;
+ }
+ if (is_last)
+ EMIT_DATA_CB(header_value, buf + mark, (i - mark) + 1);
+ break;
+
+ case s_header_value_almost_done:
+ multipart_log("s_header_value_almost_done");
+ if (c != LF) {
+ return i;
+ }
+ p->state = s_header_field_start;
+ break;
+
+ case s_part_data_start:
+ multipart_log("s_part_data_start");
+ NOTIFY_CB(headers_complete);
+ mark = i;
+ p->state = s_part_data;
+
+ /* fallthrough */
+ case s_part_data:
+ multipart_log("s_part_data");
+ if (c == CR) {
+ EMIT_DATA_CB(part_data, buf + mark, i - mark);
+ mark = i;
+ p->state = s_part_data_almost_boundary;
+ p->lookbehind[0] = CR;
+ break;
+ }
+ if (is_last)
+ EMIT_DATA_CB(part_data, buf + mark, (i - mark) + 1);
+ break;
+
+ case s_part_data_almost_boundary:
+ multipart_log("s_part_data_almost_boundary");
+ if (c == LF) {
+ p->state = s_part_data_boundary;
+ p->lookbehind[1] = LF;
+ p->index = 0;
+ break;
+ }
+ EMIT_DATA_CB(part_data, p->lookbehind, 1);
+ p->state = s_part_data;
+ mark = i --;
+ break;
+
+ case s_part_data_boundary:
+ multipart_log("s_part_data_boundary");
+ if (p->multipart_boundary[p->index] != c) {
+ EMIT_DATA_CB(part_data, p->lookbehind, 2 + p->index);
+ p->state = s_part_data;
+ mark = i --;
+ break;
+ }
+ p->lookbehind[2 + p->index] = c;
+ if ((++ p->index) == p->boundary_length) {
+ NOTIFY_CB(part_data_end);
+ p->state = s_part_data_almost_end;
+ }
+ break;
+
+ case s_part_data_almost_end:
+ multipart_log("s_part_data_almost_end");
+ if (c == '-') {
+ p->state = s_part_data_final_hyphen;
+ break;
+ }
+ if (c == CR) {
+ p->state = s_part_data_end;
+ break;
+ }
+ return i;
+
+ case s_part_data_final_hyphen:
+ multipart_log("s_part_data_final_hyphen");
+ if (c == '-') {
+ NOTIFY_CB(body_end);
+ p->state = s_end;
+ break;
+ }
+ return i;
+
+ case s_part_data_end:
+ multipart_log("s_part_data_end");
+ if (c == LF) {
+ p->state = s_header_field_start;
+ NOTIFY_CB(part_data_begin);
+ break;
+ }
+ return i;
+
+ case s_end:
+ multipart_log("s_end: %02X", (int) c);
+ break;
+
+ default:
+ multipart_log("Multipart parser unrecoverable error");
+ return 0;
+ }
+ ++ i;
+ }
+
+ return len;
+}