diff options
Diffstat (limited to 'src/basic')
| -rw-r--r-- | src/basic/io-util.c | 5 | ||||
| -rw-r--r-- | src/basic/socket-util.c | 78 | ||||
| -rw-r--r-- | src/basic/socket-util.h | 4 |
3 files changed, 87 insertions, 0 deletions
diff --git a/src/basic/io-util.c b/src/basic/io-util.c index 0037a37f2a..cc6dfa8c1b 100644 --- a/src/basic/io-util.c +++ b/src/basic/io-util.c @@ -33,6 +33,11 @@ int flush_fd(int fd) { .events = POLLIN, }; + /* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything + * read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read + * (due to IP packet checksum mismatches), hence this function is only safe to be non-blocking if the fd used + * was set to non-blocking too. */ + for (;;) { char buf[LINE_MAX]; ssize_t l; diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c index 0f38f9a0f3..c8769a54f4 100644 --- a/src/basic/socket-util.c +++ b/src/basic/socket-util.c @@ -23,6 +23,7 @@ #include <net/if.h> #include <netdb.h> #include <netinet/ip.h> +#include <poll.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> @@ -42,7 +43,9 @@ #include "socket-util.h" #include "string-table.h" #include "string-util.h" +#include "strv.h" #include "user-util.h" +#include "utf8.h" #include "util.h" int socket_address_parse(SocketAddress *a, const char *s) { @@ -794,6 +797,42 @@ static const char* const ip_tos_table[] = { DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff); +bool ifname_valid(const char *p) { + bool numeric = true; + + /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources + * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We + * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */ + + if (isempty(p)) + return false; + + if (strlen(p) >= IFNAMSIZ) + return false; + + if (STR_IN_SET(p, ".", "..")) + return false; + + while (*p) { + if ((unsigned char) *p >= 127U) + return false; + + if ((unsigned char) *p <= 32U) + return false; + + if (*p == ':' || *p == '/') + return false; + + numeric = numeric && (*p >= '0' && *p <= '9'); + p++; + } + + if (numeric) + return false; + + return true; +} + int getpeercred(int fd, struct ucred *ucred) { socklen_t n = sizeof(struct ucred); struct ucred u; @@ -970,3 +1009,42 @@ fallback: return (ssize_t) k; } + +int flush_accept(int fd) { + + struct pollfd pollfd = { + .fd = fd, + .events = POLLIN, + }; + int r; + + + /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */ + + for (;;) { + int cfd; + + r = poll(&pollfd, 1, 0); + if (r < 0) { + if (errno == EINTR) + continue; + + return -errno; + + } else if (r == 0) + return 0; + + cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (cfd < 0) { + if (errno == EINTR) + continue; + + if (errno == EAGAIN) + return 0; + + return -errno; + } + + close(cfd); + } +} diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h index daa4b24a37..e9230e4a9f 100644 --- a/src/basic/socket-util.h +++ b/src/basic/socket-util.h @@ -123,6 +123,8 @@ int fd_inc_rcvbuf(int fd, size_t n); int ip_tos_to_string_alloc(int i, char **s); int ip_tos_from_string(const char *s); +bool ifname_valid(const char *p); + int getpeercred(int fd, struct ucred *ucred); int getpeersec(int fd, char **ret); @@ -135,6 +137,8 @@ int receive_one_fd(int transport_fd, int flags); ssize_t next_datagram_size_fd(int fd); +int flush_accept(int fd); + #define CMSG_FOREACH(cmsg, mh) \ for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg))) |