diff options
Diffstat (limited to 'passt-repair.c')
| -rw-r--r-- | passt-repair.c | 113 |
1 files changed, 101 insertions, 12 deletions
diff --git a/passt-repair.c b/passt-repair.c index 614cee0..8c59d7e 100644 --- a/passt-repair.c +++ b/passt-repair.c @@ -16,11 +16,14 @@ * off. Reply by echoing the command. Exit on EOF. */ +#include <sys/inotify.h> #include <sys/prctl.h> #include <sys/types.h> #include <sys/socket.h> +#include <sys/stat.h> #include <sys/un.h> #include <errno.h> +#include <stdbool.h> #include <stddef.h> #include <stdio.h> #include <stdlib.h> @@ -39,6 +42,8 @@ #include "seccomp_repair.h" #define SCM_MAX_FD 253 /* From Linux kernel (include/net/scm.h), not in UAPI */ +#define REPAIR_EXT ".repair" +#define REPAIR_EXT_LEN strlen(REPAIR_EXT) /** * main() - Entry point and whole program with loop @@ -51,6 +56,9 @@ * #syscalls:repair socket s390x:socketcall i686:socketcall * #syscalls:repair recvfrom recvmsg arm:recv ppc64le:recv * #syscalls:repair sendto sendmsg arm:send ppc64le:send + * #syscalls:repair stat|statx stat64|statx statx + * #syscalls:repair fstat|fstat64 newfstatat|fstatat64 + * #syscalls:repair inotify_init1 inotify_add_watch */ int main(int argc, char **argv) { @@ -58,11 +66,14 @@ int main(int argc, char **argv) __attribute__ ((aligned(__alignof__(struct cmsghdr)))); struct sockaddr_un a = { AF_UNIX, "" }; int fds[SCM_MAX_FD], s, ret, i, n = 0; + bool inotify_dir = false; struct sock_fprog prog; int8_t cmd = INT8_MAX; struct cmsghdr *cmsg; struct msghdr msg; struct iovec iov; + size_t cmsg_len; + struct stat sb; int op; prctl(PR_SET_DUMPABLE, 0); @@ -72,7 +83,7 @@ int main(int argc, char **argv) prog.filter = filter_repair; if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) || prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog)) { - fprintf(stderr, "Failed to apply seccomp filter"); + fprintf(stderr, "Failed to apply seccomp filter\n"); _exit(1); } @@ -89,19 +100,96 @@ int main(int argc, char **argv) _exit(2); } - ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[1]); + if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) { + fprintf(stderr, "Failed to create AF_UNIX socket: %i\n", errno); + _exit(1); + } + + if ((stat(argv[1], &sb))) { + fprintf(stderr, "Can't stat() %s: %i\n", argv[1], errno); + _exit(1); + } + + if ((sb.st_mode & S_IFMT) == S_IFDIR) { + char buf[sizeof(struct inotify_event) + NAME_MAX + 1] + __attribute__ ((aligned(__alignof__(struct inotify_event)))); + const struct inotify_event *ev = NULL; + char path[PATH_MAX + 1]; + bool found = false; + ssize_t n; + int fd; + + if ((fd = inotify_init1(IN_CLOEXEC)) < 0) { + fprintf(stderr, "inotify_init1: %i\n", errno); + _exit(1); + } + + if (inotify_add_watch(fd, argv[1], IN_CREATE) < 0) { + fprintf(stderr, "inotify_add_watch: %i\n", errno); + _exit(1); + } + + do { + char *p; + + n = read(fd, buf, sizeof(buf)); + if (n < 0) { + fprintf(stderr, "inotify read: %i\n", errno); + _exit(1); + } + buf[n - 1] = '\0'; + + if (n < (ssize_t)sizeof(*ev)) { + fprintf(stderr, "Short inotify read: %zi\n", n); + continue; + } + + for (p = buf; p < buf + n; p += sizeof(*ev) + ev->len) { + ev = (const struct inotify_event *)p; + + if (ev->len >= REPAIR_EXT_LEN && + !memcmp(ev->name + + strnlen(ev->name, ev->len) - + REPAIR_EXT_LEN, + REPAIR_EXT, REPAIR_EXT_LEN)) { + found = true; + break; + } + } + } while (!found); + + if (ev->len > NAME_MAX + 1 || ev->name[ev->len - 1] != '\0') { + fprintf(stderr, "Invalid filename from inotify\n"); + _exit(1); + } + + snprintf(path, sizeof(path), "%s/%s", argv[1], ev->name); + if ((stat(path, &sb))) { + fprintf(stderr, "Can't stat() %s: %i\n", path, errno); + _exit(1); + } + + ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", path); + inotify_dir = true; + } else { + ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[1]); + } + if (ret <= 0 || ret >= (int)sizeof(a.sun_path)) { - fprintf(stderr, "Invalid socket path: %s\n", argv[1]); + fprintf(stderr, "Invalid socket path\n"); _exit(2); } - if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) { - fprintf(stderr, "Failed to create AF_UNIX socket: %i\n", errno); - _exit(1); + if ((sb.st_mode & S_IFMT) != S_IFSOCK) { + fprintf(stderr, "%s is not a socket\n", a.sun_path); + _exit(2); } - if (connect(s, (struct sockaddr *)&a, sizeof(a))) { - fprintf(stderr, "Failed to connect to %s: %s\n", argv[1], + while (connect(s, (struct sockaddr *)&a, sizeof(a))) { + if (inotify_dir && errno == ECONNREFUSED) + continue; + + fprintf(stderr, "Failed to connect to %s: %s\n", a.sun_path, strerror(errno)); _exit(1); } @@ -131,15 +219,16 @@ loop: /* No inverse formula for CMSG_LEN(x), and building one with CMSG_LEN(0) * works but there's no guarantee it does. Search the whole domain. */ - for (i = 1; i < SCM_MAX_FD; i++) { + for (i = 1; i <= SCM_MAX_FD; i++) { if (CMSG_LEN(sizeof(int) * i) == cmsg->cmsg_len) { n = i; break; } } if (!n) { + cmsg_len = cmsg->cmsg_len; /* socklen_t is 'unsigned' on musl */ fprintf(stderr, "Invalid ancillary data length %zu from peer\n", - cmsg->cmsg_len); + cmsg_len); _exit(1); } @@ -156,8 +245,8 @@ loop: for (i = 0; i < n; i++) { if (setsockopt(fds[i], SOL_TCP, TCP_REPAIR, &op, sizeof(op))) { fprintf(stderr, - "Setting TCP_REPAIR to %i on socket %i: %s", op, - fds[i], strerror(errno)); + "Setting TCP_REPAIR to %i on socket %i: %s\n", + op, fds[i], strerror(errno)); _exit(1); } |