From 45f3a13c816656c9d3d311880d90286341644d9b Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 15 Mar 2021 16:51:46 -0500 Subject: net: qualcomm: rmnet: mark trailer field endianness The fields in the checksum trailer structure used for QMAP protocol RX packets are all big-endian format, so define them that way. It turns out these fields are never actually used by the RMNet code. The start offset is always assumed to be zero, and the length is taken from the other packet headers. So making these fields explicitly big endian has no effect on the behavior of the code. Signed-off-by: Alex Elder Reviewed-by: Bjorn Andersson Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller --- include/linux/if_rmnet.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h index 9661416a9bb4..8c7845baf383 100644 --- a/include/linux/if_rmnet.h +++ b/include/linux/if_rmnet.h @@ -32,8 +32,8 @@ struct rmnet_map_dl_csum_trailer { #else #error "Please fix " #endif - u16 csum_start_offset; - u16 csum_length; + __be16 csum_start_offset; + __be16 csum_length; __be16 csum_value; } __aligned(1); -- cgit v1.2.3 From 16653c16d282e768763b2e8cc78f75df8fd53992 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 15 Mar 2021 16:51:49 -0500 Subject: net: qualcomm: rmnet: use masks instead of C bit-fields The actual layout of bits defined in C bit-fields (e.g. int foo : 3) is implementation-defined. Structures defined in address this by specifying all bit-fields twice, to cover two possible layouts. I think this pattern is repetitive and noisy, and I find the whole notion of compiler "bitfield endianness" to be non-intuitive. Stop using C bit-fields for the command/data flag and the pad length fields in the rmnet_map structure, and define a single-byte flags field instead. Define a mask for the single-bit "command" flag, and another mask for the encoded pad length. The content of both fields can be accessed using a simple bitwise AND operation. Signed-off-by: Alex Elder Reviewed-by: Bjorn Andersson Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller --- .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 4 ++-- .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 4 +++- include/linux/if_rmnet.h | 23 ++++++++++------------ 3 files changed, 15 insertions(+), 16 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c index 2a6b2a609884..0be5ac7ab261 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -61,7 +61,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb, u16 len, pad; u8 mux_id; - if (map_header->cd_bit) { + if (map_header->flags & MAP_CMD_FLAG) { /* Packet contains a MAP command (not data) */ if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS) return rmnet_map_command(skb, port); @@ -70,7 +70,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb, } mux_id = map_header->mux_id; - pad = map_header->pad_len; + pad = map_header->flags & MAP_PAD_LEN_MASK; len = ntohs(map_header->pkt_len) - pad; if (mux_id >= RMNET_MAX_LOGICAL_EP) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index 3af68368fc31..e7d0394cb297 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -280,6 +280,7 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, return map_header; } + BUILD_BUG_ON(MAP_PAD_LEN_MASK < 3); padding = ALIGN(map_datalen, 4) - map_datalen; if (padding == 0) @@ -293,7 +294,8 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, done: map_header->pkt_len = htons(map_datalen + padding); - map_header->pad_len = padding & 0x3F; + /* This is a data packet, so the CMD bit is 0 */ + map_header->flags = padding & MAP_PAD_LEN_MASK; return map_header; } diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h index 8c7845baf383..a02f0a3df1d9 100644 --- a/include/linux/if_rmnet.h +++ b/include/linux/if_rmnet.h @@ -6,21 +6,18 @@ #define _LINUX_IF_RMNET_H_ struct rmnet_map_header { -#if defined(__LITTLE_ENDIAN_BITFIELD) - u8 pad_len:6; - u8 reserved_bit:1; - u8 cd_bit:1; -#elif defined (__BIG_ENDIAN_BITFIELD) - u8 cd_bit:1; - u8 reserved_bit:1; - u8 pad_len:6; -#else -#error "Please fix " -#endif - u8 mux_id; - __be16 pkt_len; + u8 flags; /* MAP_CMD_FLAG, MAP_PAD_LEN_MASK */ + u8 mux_id; + __be16 pkt_len; /* Length of packet, including pad */ } __aligned(1); +/* rmnet_map_header flags field: + * PAD_LEN: number of pad bytes following packet data + * CMD: 1 = packet contains a MAP command; 0 = packet contains data + */ +#define MAP_PAD_LEN_MASK GENMASK(5, 0) +#define MAP_CMD_FLAG BIT(7) + struct rmnet_map_dl_csum_trailer { u8 reserved1; #if defined(__LITTLE_ENDIAN_BITFIELD) -- cgit v1.2.3 From cc1b21ba6251c8dd8e4e86018c9fdba85df0d219 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 15 Mar 2021 16:51:50 -0500 Subject: net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum trailer Replace the use of C bit-fields in the rmnet_map_dl_csum_trailer structure with a single one-byte field, using constant field masks to encode or get at embedded values. Signed-off-by: Alex Elder Reviewed-by: Bjorn Andersson Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 2 +- include/linux/if_rmnet.h | 17 +++++++---------- 2 files changed, 8 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index e7d0394cb297..c336c17e01fe 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -359,7 +359,7 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len) csum_trailer = (struct rmnet_map_dl_csum_trailer *)(skb->data + len); - if (!csum_trailer->valid) { + if (!(csum_trailer->flags & MAP_CSUM_DL_VALID_FLAG)) { priv->stats.csum_valid_unset++; return -EINVAL; } diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h index a02f0a3df1d9..941997df9e08 100644 --- a/include/linux/if_rmnet.h +++ b/include/linux/if_rmnet.h @@ -19,21 +19,18 @@ struct rmnet_map_header { #define MAP_CMD_FLAG BIT(7) struct rmnet_map_dl_csum_trailer { - u8 reserved1; -#if defined(__LITTLE_ENDIAN_BITFIELD) - u8 valid:1; - u8 reserved2:7; -#elif defined (__BIG_ENDIAN_BITFIELD) - u8 reserved2:7; - u8 valid:1; -#else -#error "Please fix " -#endif + u8 reserved1; + u8 flags; /* MAP_CSUM_DL_VALID_FLAG */ __be16 csum_start_offset; __be16 csum_length; __be16 csum_value; } __aligned(1); +/* rmnet_map_dl_csum_trailer flags field: + * VALID: 1 = checksum and length valid; 0 = ignore them + */ +#define MAP_CSUM_DL_VALID_FLAG BIT(0) + struct rmnet_map_ul_csum_header { __be16 csum_start_offset; #if defined(__LITTLE_ENDIAN_BITFIELD) -- cgit v1.2.3 From 86ca860e12ec0feab7d721d3b05e60fb86613540 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 15 Mar 2021 16:51:51 -0500 Subject: net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum header Replace the use of C bit-fields in the rmnet_map_ul_csum_header structure with a single two-byte (big endian) structure member, and use masks to encode or get values within it. The content of these fields can be accessed using simple bitwise AND and OR operations on the (host byte order) value of the new structure member. Previously rmnet_map_ipv4_ul_csum_header() would update C bit-field values in host byte order, then forcibly fix their byte order using a combination of byte swap operations and types. Instead, just compute the value that needs to go into the new structure member and save it with a simple byte-order conversion. Make similar simplifications in rmnet_map_ipv6_ul_csum_header(). Finally, in rmnet_map_checksum_uplink_packet() a set of assignments zeroes every field in the upload checksum header. Replace that with a single memset() operation. Signed-off-by: Alex Elder Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller --- .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 38 ++++++++-------------- include/linux/if_rmnet.h | 21 ++++++------ 2 files changed, 23 insertions(+), 36 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index c336c17e01fe..0ac2ff828320 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -197,20 +197,16 @@ rmnet_map_ipv4_ul_csum_header(void *iphdr, struct rmnet_map_ul_csum_header *ul_header, struct sk_buff *skb) { - __be16 *hdr = (__be16 *)ul_header; struct iphdr *ip4h = iphdr; + u16 val; - ul_header->csum_start_offset = htons(skb_network_header_len(skb)); - ul_header->csum_insert_offset = skb->csum_offset; - ul_header->csum_enabled = 1; + val = MAP_CSUM_UL_ENABLED_FLAG; if (ip4h->protocol == IPPROTO_UDP) - ul_header->udp_ind = 1; - else - ul_header->udp_ind = 0; + val |= MAP_CSUM_UL_UDP_FLAG; + val |= skb->csum_offset & MAP_CSUM_UL_OFFSET_MASK; - /* Changing remaining fields to network order */ - hdr++; - *hdr = htons((__force u16)*hdr); + ul_header->csum_start_offset = htons(skb_network_header_len(skb)); + ul_header->csum_info = htons(val); skb->ip_summed = CHECKSUM_NONE; @@ -237,21 +233,16 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr, struct rmnet_map_ul_csum_header *ul_header, struct sk_buff *skb) { - __be16 *hdr = (__be16 *)ul_header; struct ipv6hdr *ip6h = ip6hdr; + u16 val; - ul_header->csum_start_offset = htons(skb_network_header_len(skb)); - ul_header->csum_insert_offset = skb->csum_offset; - ul_header->csum_enabled = 1; - + val = MAP_CSUM_UL_ENABLED_FLAG; if (ip6h->nexthdr == IPPROTO_UDP) - ul_header->udp_ind = 1; - else - ul_header->udp_ind = 0; + val |= MAP_CSUM_UL_UDP_FLAG; + val |= skb->csum_offset & MAP_CSUM_UL_OFFSET_MASK; - /* Changing remaining fields to network order */ - hdr++; - *hdr = htons((__force u16)*hdr); + ul_header->csum_start_offset = htons(skb_network_header_len(skb)); + ul_header->csum_info = htons(val); skb->ip_summed = CHECKSUM_NONE; @@ -419,10 +410,7 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb, } sw_csum: - ul_header->csum_start_offset = 0; - ul_header->csum_insert_offset = 0; - ul_header->csum_enabled = 0; - ul_header->udp_ind = 0; + memset(ul_header, 0, sizeof(*ul_header)); priv->stats.csum_sw++; } diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h index 941997df9e08..4efb537f57f3 100644 --- a/include/linux/if_rmnet.h +++ b/include/linux/if_rmnet.h @@ -33,17 +33,16 @@ struct rmnet_map_dl_csum_trailer { struct rmnet_map_ul_csum_header { __be16 csum_start_offset; -#if defined(__LITTLE_ENDIAN_BITFIELD) - u16 csum_insert_offset:14; - u16 udp_ind:1; - u16 csum_enabled:1; -#elif defined (__BIG_ENDIAN_BITFIELD) - u16 csum_enabled:1; - u16 udp_ind:1; - u16 csum_insert_offset:14; -#else -#error "Please fix " -#endif + __be16 csum_info; /* MAP_CSUM_UL_* */ } __aligned(1); +/* csum_info field: + * OFFSET: where (offset in bytes) to insert computed checksum + * UDP: 1 = UDP checksum (zero checkum means no checksum) + * ENABLED: 1 = checksum computation requested + */ +#define MAP_CSUM_UL_OFFSET_MASK GENMASK(13, 0) +#define MAP_CSUM_UL_UDP_FLAG BIT(14) +#define MAP_CSUM_UL_ENABLED_FLAG BIT(15) + #endif /* !(_LINUX_IF_RMNET_H_) */ -- cgit v1.2.3