From 9de731ed29db4670c1641aedd945c56fd1a3feed Mon Sep 17 00:00:00 2001 From: Ray Strode Date: Wed, 6 Oct 2010 17:43:50 -0400 Subject: [PATCH] utils: add support for "trimmed abstract" sockets Right now plymouth listens on an abstract socket with a name that has a bunch of trailing NUL bytes. These zeroes uglify the output of /proc/net/unix among other things. This commit adds support for a new "trimmed abstract" socket type, which drops the zeroes. A subsequent commit will actually change plymouthd to use the new api. --- src/client/ply-boot-client.c | 5 ++-- src/libply/ply-utils.c | 44 ++++++++++++++++++++++++------------ src/libply/ply-utils.h | 13 ++++++++--- src/ply-boot-server.c | 3 ++- 4 files changed, 44 insertions(+), 21 deletions(-) diff --git a/src/client/ply-boot-client.c b/src/client/ply-boot-client.c index 48f32583..5fe30132 100644 --- a/src/client/ply-boot-client.c +++ b/src/client/ply-boot-client.c @@ -179,8 +179,9 @@ ply_boot_client_connect (ply_boot_client_t *client, assert (client->disconnect_handler == NULL); assert (client->disconnect_handler_user_data == NULL); - client->socket_fd = - ply_connect_to_unix_socket (PLY_BOOT_PROTOCOL_SOCKET_PATH + 1, true); + client->socket_fd = + ply_connect_to_unix_socket (PLY_BOOT_PROTOCOL_SOCKET_PATH + 1, + PLY_UNIX_SOCKET_TYPE_ABSTRACT); if (client->socket_fd < 0) return false; diff --git a/src/libply/ply-utils.c b/src/libply/ply-utils.c index a65c469a..633ff1c8 100644 --- a/src/libply/ply-utils.c +++ b/src/libply/ply-utils.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -146,9 +147,9 @@ ply_open_unix_socket (void) } static struct sockaddr * -create_unix_address_from_path (const char *path, - bool is_abstract, - size_t *address_size) +create_unix_address_from_path (const char *path, + ply_unix_socket_type_t type, + size_t *address_size) { struct sockaddr_un *address; @@ -159,26 +160,39 @@ create_unix_address_from_path (const char *path, address->sun_family = AF_UNIX; /* a socket is marked as abstract if its path has the - * NUL byte at the beginning of the buffer instead of - * the end + * NUL byte at the beginning of the buffer. * * Note, we depend on the memory being zeroed by the calloc * call above. */ - if (!is_abstract) + if (type == PLY_UNIX_SOCKET_TYPE_ABSTRACT) strncpy (address->sun_path, path, sizeof (address->sun_path) - 1); else strncpy (address->sun_path + 1, path, sizeof (address->sun_path) - 1); - if (address_size != NULL) - *address_size = sizeof (struct sockaddr_un); + assert (address_size != NULL); + + /* it's very popular to trim the trailing zeros off the end of the path these + * days for abstract sockets. Unfortunately, the 0s are part of the name, so + * both client and server have to agree. + */ + if (type == PLY_UNIX_SOCKET_TYPE_TRIMMED_ABSTRACT) + { + *address_size = offsetof (struct sockaddr_un, sun_path) + + 1 /* NUL */ + + strlen (address->sun_path + 1) /* path */; + } + else + { + *address_size = sizeof (struct sockaddr_un); + } return (struct sockaddr *) address; } int -ply_connect_to_unix_socket (const char *path, - bool is_abstract) +ply_connect_to_unix_socket (const char *path, + ply_unix_socket_type_t type) { struct sockaddr *address; size_t address_size; @@ -192,7 +206,7 @@ ply_connect_to_unix_socket (const char *path, if (fd < 0) return -1; - address = create_unix_address_from_path (path, is_abstract, &address_size); + address = create_unix_address_from_path (path, type, &address_size); if (connect (fd, address, address_size) < 0) { @@ -209,8 +223,8 @@ ply_connect_to_unix_socket (const char *path, } int -ply_listen_to_unix_socket (const char *path, - bool is_abstract) +ply_listen_to_unix_socket (const char *path, + ply_unix_socket_type_t type) { struct sockaddr *address; size_t address_size; @@ -224,7 +238,7 @@ ply_listen_to_unix_socket (const char *path, if (fd < 0) return -1; - address = create_unix_address_from_path (path, is_abstract, &address_size); + address = create_unix_address_from_path (path, type, &address_size); if (bind (fd, address, address_size) < 0) { @@ -246,7 +260,7 @@ ply_listen_to_unix_socket (const char *path, return -1; } - if (!is_abstract) + if (type == PLY_UNIX_SOCKET_TYPE_CONCRETE) { if (fchmod (fd, 0600) < 0) { diff --git a/src/libply/ply-utils.h b/src/libply/ply-utils.h index 8af8172d..25500107 100644 --- a/src/libply/ply-utils.h +++ b/src/libply/ply-utils.h @@ -45,16 +45,23 @@ typedef void (* ply_module_function_t) (void); typedef intptr_t ply_daemon_handle_t; +typedef enum +{ + PLY_UNIX_SOCKET_TYPE_CONCRETE = 0, + PLY_UNIX_SOCKET_TYPE_ABSTRACT, + PLY_UNIX_SOCKET_TYPE_TRIMMED_ABSTRACT +} ply_unix_socket_type_t; + #ifndef PLY_HIDE_FUNCTION_DECLARATIONS #define ply_round_to_multiple(n, m) (((n) + (((m) - 1))) & ~((m) - 1)) bool ply_open_unidirectional_pipe (int *sender_fd, int *receiver_fd); -int ply_connect_to_unix_socket (const char *path, - bool is_abstract); +int ply_connect_to_unix_socket (const char *path, + ply_unix_socket_type_t type); int ply_listen_to_unix_socket (const char *path, - bool is_abstract); + ply_unix_socket_type_t type); bool ply_get_credentials_from_fd (int fd, pid_t *pid, uid_t *uid, diff --git a/src/ply-boot-server.c b/src/ply-boot-server.c index 297074ec..337d22a4 100644 --- a/src/ply-boot-server.c +++ b/src/ply-boot-server.c @@ -179,7 +179,8 @@ ply_boot_server_listen (ply_boot_server_t *server) assert (server != NULL); server->socket_fd = - ply_listen_to_unix_socket (PLY_BOOT_PROTOCOL_SOCKET_PATH + 1, true); + ply_listen_to_unix_socket (PLY_BOOT_PROTOCOL_SOCKET_PATH + 1, + PLY_UNIX_SOCKET_TYPE_ABSTRACT); if (server->socket_fd < 0) return false; -- 2.47.3