From e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Fri, 28 Aug 2015 09:58:54 +0800 Subject: Add qemu 2.4.0 Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang --- qemu/slirp/mbuf.c | 241 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 qemu/slirp/mbuf.c (limited to 'qemu/slirp/mbuf.c') diff --git a/qemu/slirp/mbuf.c b/qemu/slirp/mbuf.c new file mode 100644 index 000000000..4fefb043b --- /dev/null +++ b/qemu/slirp/mbuf.c @@ -0,0 +1,241 @@ +/* + * Copyright (c) 1995 Danny Gasparovski + * + * Please read the file COPYRIGHT for the + * terms and conditions of the copyright. + */ + +/* + * mbuf's in SLiRP are much simpler than the real mbufs in + * FreeBSD. They are fixed size, determined by the MTU, + * so that one whole packet can fit. Mbuf's cannot be + * chained together. If there's more data than the mbuf + * could hold, an external malloced buffer is pointed to + * by m_ext (and the data pointers) and M_EXT is set in + * the flags + */ + +#include + +#define MBUF_THRESH 30 + +/* + * Find a nice value for msize + * XXX if_maxlinkhdr already in mtu + */ +#define SLIRP_MSIZE (IF_MTU + IF_MAXLINKHDR + offsetof(struct mbuf, m_dat) + 6) + +void +m_init(Slirp *slirp) +{ + slirp->m_freelist.m_next = slirp->m_freelist.m_prev = &slirp->m_freelist; + slirp->m_usedlist.m_next = slirp->m_usedlist.m_prev = &slirp->m_usedlist; +} + +void m_cleanup(Slirp *slirp) +{ + struct mbuf *m, *next; + + m = slirp->m_usedlist.m_next; + while (m != &slirp->m_usedlist) { + next = m->m_next; + if (m->m_flags & M_EXT) { + free(m->m_ext); + } + free(m); + m = next; + } + m = slirp->m_freelist.m_next; + while (m != &slirp->m_freelist) { + next = m->m_next; + free(m); + m = next; + } +} + +/* + * Get an mbuf from the free list, if there are none + * malloc one + * + * Because fragmentation can occur if we alloc new mbufs and + * free old mbufs, we mark all mbufs above mbuf_thresh as M_DOFREE, + * which tells m_free to actually free() it + */ +struct mbuf * +m_get(Slirp *slirp) +{ + register struct mbuf *m; + int flags = 0; + + DEBUG_CALL("m_get"); + + if (slirp->m_freelist.m_next == &slirp->m_freelist) { + m = (struct mbuf *)malloc(SLIRP_MSIZE); + if (m == NULL) goto end_error; + slirp->mbuf_alloced++; + if (slirp->mbuf_alloced > MBUF_THRESH) + flags = M_DOFREE; + m->slirp = slirp; + } else { + m = slirp->m_freelist.m_next; + remque(m); + } + + /* Insert it in the used list */ + insque(m,&slirp->m_usedlist); + m->m_flags = (flags | M_USEDLIST); + + /* Initialise it */ + m->m_size = SLIRP_MSIZE - offsetof(struct mbuf, m_dat); + m->m_data = m->m_dat; + m->m_len = 0; + m->m_nextpkt = NULL; + m->m_prevpkt = NULL; + m->arp_requested = false; + m->expiration_date = (uint64_t)-1; +end_error: + DEBUG_ARG("m = %lx", (long )m); + return m; +} + +void +m_free(struct mbuf *m) +{ + + DEBUG_CALL("m_free"); + DEBUG_ARG("m = %lx", (long )m); + + if(m) { + /* Remove from m_usedlist */ + if (m->m_flags & M_USEDLIST) + remque(m); + + /* If it's M_EXT, free() it */ + if (m->m_flags & M_EXT) + free(m->m_ext); + + /* + * Either free() it or put it on the free list + */ + if (m->m_flags & M_DOFREE) { + m->slirp->mbuf_alloced--; + free(m); + } else if ((m->m_flags & M_FREELIST) == 0) { + insque(m,&m->slirp->m_freelist); + m->m_flags = M_FREELIST; /* Clobber other flags */ + } + } /* if(m) */ +} + +/* + * Copy data from one mbuf to the end of + * the other.. if result is too big for one mbuf, malloc() + * an M_EXT data segment + */ +void +m_cat(struct mbuf *m, struct mbuf *n) +{ + /* + * If there's no room, realloc + */ + if (M_FREEROOM(m) < n->m_len) + m_inc(m,m->m_size+MINCSIZE); + + memcpy(m->m_data+m->m_len, n->m_data, n->m_len); + m->m_len += n->m_len; + + m_free(n); +} + + +/* make m size bytes large */ +void +m_inc(struct mbuf *m, int size) +{ + int datasize; + + /* some compiles throw up on gotos. This one we can fake. */ + if(m->m_size>size) return; + + if (m->m_flags & M_EXT) { + datasize = m->m_data - m->m_ext; + m->m_ext = (char *)realloc(m->m_ext,size); + m->m_data = m->m_ext + datasize; + } else { + char *dat; + datasize = m->m_data - m->m_dat; + dat = (char *)malloc(size); + memcpy(dat, m->m_dat, m->m_size); + + m->m_ext = dat; + m->m_data = m->m_ext + datasize; + m->m_flags |= M_EXT; + } + + m->m_size = size; + +} + + + +void +m_adj(struct mbuf *m, int len) +{ + if (m == NULL) + return; + if (len >= 0) { + /* Trim from head */ + m->m_data += len; + m->m_len -= len; + } else { + /* Trim from tail */ + len = -len; + m->m_len -= len; + } +} + + +/* + * Copy len bytes from m, starting off bytes into n + */ +int +m_copy(struct mbuf *n, struct mbuf *m, int off, int len) +{ + if (len > M_FREEROOM(n)) + return -1; + + memcpy((n->m_data + n->m_len), (m->m_data + off), len); + n->m_len += len; + return 0; +} + + +/* + * Given a pointer into an mbuf, return the mbuf + * XXX This is a kludge, I should eliminate the need for it + * Fortunately, it's not used often + */ +struct mbuf * +dtom(Slirp *slirp, void *dat) +{ + struct mbuf *m; + + DEBUG_CALL("dtom"); + DEBUG_ARG("dat = %lx", (long )dat); + + /* bug corrected for M_EXT buffers */ + for (m = slirp->m_usedlist.m_next; m != &slirp->m_usedlist; + m = m->m_next) { + if (m->m_flags & M_EXT) { + if( (char *)dat>=m->m_ext && (char *)dat<(m->m_ext + m->m_size) ) + return m; + } else { + if( (char *)dat >= m->m_dat && (char *)dat<(m->m_dat + m->m_size) ) + return m; + } + } + + DEBUG_ERROR((dfd, "dtom failed")); + + return (struct mbuf *)0; +} -- cgit 1.2.3-korg