From dad9af6a2024343fc673348fe763dafcd6830d1f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 30 Apr 2015 01:24:48 +0200 Subject: [PATCH] sd-bus: when we get ENOTTY on the HELLO ioctl assume incompatible API version As perparation for future incompatible kdbus kernel API changes. --- src/libelogind/sd-bus/bus-kernel.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/src/libelogind/sd-bus/bus-kernel.c b/src/libelogind/sd-bus/bus-kernel.c index 556b5eb70..8e3b64337 100644 --- a/src/libelogind/sd-bus/bus-kernel.c +++ b/src/libelogind/sd-bus/bus-kernel.c @@ -962,8 +962,16 @@ int bus_kernel_take_fd(sd_bus *b) { } r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello); - if (r < 0) + if (r < 0) { + if (errno == ENOTTY) + /* If the ioctl is not supported we assume that the + * API version changed in a major incompatible way, + * let's indicate an API incompatibility in this + * case. */ + return -ESOCKTNOSUPPORT; + return -errno; + } if (!b->kdbus_buffer) { b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0); @@ -977,7 +985,7 @@ int bus_kernel_take_fd(sd_bus *b) { /* The higher 32bit of the bus_flags fields are considered * 'incompatible flags'. Refuse them all for now. */ if (hello->bus_flags > 0xFFFFFFFFULL) { - r = -EOPNOTSUPP; + r = -ESOCKTNOSUPPORT; goto fail; } @@ -1611,6 +1619,11 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) { if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) { safe_close(fd); + + /* Major API change? then the ioctls got shuffled around. */ + if (errno == ENOTTY) + return -ESOCKTNOSUPPORT; + return -errno; } -- 2.30.2