/* * netsniff-ng - the packet sniffing beast * Copyright 2011 - 2013 Daniel Borkmann. * Subject to the GPL, version 2. */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include "pcap_io.h" #include "xio.h" #include "xutils.h" #include "built_in.h" #include "iosched.h" static size_t map_size = 0; static char *ptr_va_start, *ptr_va_curr; static void __pcap_mmap_write_need_remap(int fd) { int ret; off_t pos, map_size_old = map_size; off_t offset = ptr_va_curr - ptr_va_start; map_size = PAGE_ALIGN(map_size_old * 10 / 8); pos = lseek(fd, map_size, SEEK_SET); if (pos < 0) panic("Cannot lseek pcap file!\n"); ret = write_or_die(fd, "", 1); if (ret != 1) panic("Cannot write file!\n"); ptr_va_start = mremap(ptr_va_start, map_size_old, map_size, MREMAP_MAYMOVE); if (ptr_va_start == MAP_FAILED) panic("mmap of file failed!"); ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL); if (ret < 0) panic("Failed to give kernel mmap advise!\n"); ptr_va_curr = ptr_va_start + offset; } static ssize_t pcap_mm_write(int fd, pcap_pkthdr_t *phdr, enum pcap_type type, const uint8_t *packet, size_t len) { size_t hdrsize = pcap_get_hdr_length(phdr, type); if ((off_t) (ptr_va_curr - ptr_va_start) + hdrsize + len > map_size) __pcap_mmap_write_need_remap(fd); fmemcpy(ptr_va_curr, &phdr->raw, hdrsize); ptr_va_curr += hdrsize; fmemcpy(ptr_va_curr, packet, len); ptr_va_curr += len; return hdrsize + len; } static ssize_t pcap_mm_read(int fd, pcap_pkthdr_t *phdr, enum pcap_type type, uint8_t *packet, size_t len) { size_t hdrsize = pcap_get_hdr_length(phdr, type), hdrlen; if (unlikely((off_t) (ptr_va_curr + hdrsize - ptr_va_start) > map_size)) return -EIO; fmemcpy(&phdr->raw, ptr_va_curr, hdrsize); ptr_va_curr += hdrsize; hdrlen = pcap_get_length(phdr, type); if (unlikely((off_t) (ptr_va_curr + hdrlen - ptr_va_start) > map_size)) return -EIO; if (unlikely(hdrlen == 0 || hdrlen > len)) return -EINVAL; fmemcpy(packet, ptr_va_curr, hdrlen); ptr_va_curr += hdrlen; return hdrsize + hdrlen; } static inline off_t ____get_map_size(bool jumbo) { int allocsz = jumbo ? 16 : 3; return PAGE_ALIGN(sizeof(struct pcap_filehdr) + (PAGE_SIZE * allocsz) * 1024); } static void __pcap_mm_prepare_access_wr(int fd, bool jumbo) { int ret; off_t pos; struct stat sb; map_size = ____get_map_size(jumbo); ret = fstat(fd, &sb); if (ret < 0) panic("Cannot fstat pcap file!\n"); if (!S_ISREG (sb.st_mode)) panic("pcap dump file is not a regular file!\n"); pos = lseek(fd, map_size, SEEK_SET); if (pos < 0) panic("Cannot lseek pcap file!\n"); ret = write_or_die(fd, "", 1); if (ret != 1) panic("Cannot write file!\n"); ptr_va_start = mmap(0, map_size, PROT_WRITE, MAP_SHARED, fd, 0); if (ptr_va_start == MAP_FAILED) panic("mmap of file failed!"); ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL); if (ret < 0) panic("Failed to give kernel mmap advise!\n"); ptr_va_curr = ptr_va_start + sizeof(struct pcap_filehdr); } static void __pcap_mm_prepare_access_rd(int fd) { int ret; struct stat sb; ret = fstat(fd, &sb); if (ret < 0) panic("Cannot fstat pcap file!\n"); if (!S_ISREG (sb.st_mode)) panic("pcap dump file is not a regular file!\n"); map_size = sb.st_size; ptr_va_start = mmap(0, map_size, PROT_READ, MAP_SHARED | MAP_LOCKED, fd, 0); if (ptr_va_start == MAP_FAILED) panic("mmap of file failed!"); ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL); if (ret < 0) panic("Failed to give kernel mmap advise!\n"); ptr_va_curr = ptr_va_start + sizeof(struct pcap_filehdr); } static void pcap_mm_init_once(void) { set_ioprio_be(); } static int pcap_mm_prepare_access(int fd, enum pcap_mode mode, bool jumbo) { switch (mode) { case PCAP_MODE_RD: __pcap_mm_prepare_access_rd(fd); break; case PCAP_MODE_WR: __pcap_mm_prepare_access_wr(fd, jumbo); break; default: bug(); } return 0; } static void pcap_mm_fsync(int fd) { msync(ptr_va_start, (off_t) (ptr_va_curr - ptr_va_start), MS_ASYNC); } static void pcap_mm_prepare_close(int fd, enum pcap_mode mode) { int ret; ret = munmap(ptr_va_start, map_size); if (ret < 0) panic("Cannot unmap the pcap file!\n"); if (mode == PCAP_MODE_WR) { ret = ftruncate(fd, (off_t) (ptr_va_curr - ptr_va_start)); if (ret) panic("Cannot truncate the pcap file!\n"); } } const struct pcap_file_ops pcap_mm_ops = { .init_once_pcap = pcap_mm_init_once, .pull_fhdr_pcap = pcap_generic_pull_fhdr, .push_fhdr_pcap = pcap_generic_push_fhdr, .prepare_access_pcap = pcap_mm_prepare_access, .prepare_close_pcap = pcap_mm_prepare_close, .read_pcap = pcap_mm_read, .write_pcap = pcap_mm_write, .fsync_pcap = pcap_mm_fsync, }; ' class='oid'>baa3dd1cf168385d24f7b631a6a75763f6b82cd4 parent01a88f7f6bd4514de9551c3fc9a6fd9e65cbf79d (diff)
rxrpc: Pass the last Tx packet marker in the annotation buffer
When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat