ref: dfea95b3c29ef4a6de2713a946453d3a022ae0b4
dir: /sys/src/libventi/debugpacket.c/
#include <u.h> #include <libc.h> #include <venti.h> #include <libsec.h> #define MAGIC 0x54798314 #define NOTFREE(p) assert((p)->magic == MAGIC) struct Packet { char *data; int len; void (*free)(void*); void *arg; int magic; }; Packet* packetalloc(void) { Packet *p; p = vtmallocz(sizeof *p); p->free = vtfree; p->arg = nil; p->magic = MAGIC; return p; } void packetappend(Packet *p, uchar *buf, int n) { NOTFREE(p); if(n < 0) abort(); if(p->free != vtfree) sysfatal("packetappend"); p->data = vtrealloc(p->data, p->len+n); p->arg = p->data; memmove(p->data+p->len, buf, n); p->len += n; } uint packetasize(Packet *p) { NOTFREE(p); return p->len; } int packetcmp(Packet *p, Packet *q) { int i, len; NOTFREE(p); NOTFREE(q); len = p->len; if(len > q->len) len = q->len; if(len && (i=memcmp(p->data, q->data, len)) != 0) return i; if(p->len > len) return 1; if(q->len > len) return -1; return 0; } void packetconcat(Packet *p, Packet *q) { NOTFREE(p); NOTFREE(q); packetappend(p, q->data, q->len); if(q->free == vtfree) memset(q->data, 0xFE, q->len); q->free(q->arg); q->data = nil; q->len = 0; } int packetconsume(Packet *p, uchar *buf, int n) { NOTFREE(p); if(n < 0) abort(); if(p->len < n) abort(); memmove(buf, p->data, n); p->len -= n; memmove(p->data, p->data+n, p->len); return 0; } int packetcopy(Packet *p, uchar *buf, int offset, int n) { NOTFREE(p); if(offset < 0 || n < 0) abort(); if(offset > p->len) abort(); if(offset+n > p->len) n = p->len - offset; memmove(buf, p->data+offset, n); return 0; } Packet* packetdup(Packet *p, int offset, int n) { Packet *q; NOTFREE(p); if(offset < 0 || n < 0) abort(); if(offset > p->len) abort(); if(offset+n > p->len) n = p->len - offset; q = packetalloc(); packetappend(q, p->data+offset, n); return q; } Packet* packetforeign(uchar *buf, int n, void (*free)(void*), void *a) { Packet *p; if(n < 0) abort(); p = packetalloc(); p->data = (char*)buf; p->len = n; p->free = free; p->arg = a; return p; } int packetfragments(Packet *p, IOchunk *io, int nio, int offset) { NOTFREE(p); if(offset < 0) abort(); if(nio == 0) return 0; memset(io, 0, sizeof(io[0])*nio); if(offset >= p->len) return 0; io[0].addr = p->data + offset; io[0].len = p->len - offset; return p->len; } void packetfree(Packet *p) { NOTFREE(p); if(p->free == free) memset(p->data, 0xFE, p->len); p->free(p->arg); p->data = nil; p->len = 0; memset(p, 0xFB, sizeof *p); free(p); } uchar* packetheader(Packet *p, int n) { NOTFREE(p); if(n < 0) abort(); if(n > p->len) abort(); return p->data; } uchar* packetpeek(Packet *p, uchar *buf, int offset, int n) { NOTFREE(p); if(offset < 0 || n < 0) abort(); if(offset+n > p->len) abort(); return p->data+offset; } void packetprefix(Packet *p, uchar *buf, int n) { NOTFREE(p); if(n < 0) abort(); if(p->free != free) sysfatal("packetappend"); p->data = vtrealloc(p->data, p->len+n); p->arg = p->data; memmove(p->data+n, p->data, p->len); memmove(p->data, buf, n); p->len += n; } void packetsha1(Packet *p, uchar d[20]) { NOTFREE(p); sha1((uchar*)p->data, p->len, d, nil); } uint packetsize(Packet *p) { NOTFREE(p); return p->len; } Packet* packetsplit(Packet *p, int n) { Packet *q; NOTFREE(p); q = packetalloc(); q->data = vtmalloc(n); q->arg = q->data; q->free = vtfree; packetconsume(p, q->data, n); return q; } void packetstats(void) { } uchar* packettrailer(Packet *p, int n) { NOTFREE(p); if(n < 0) abort(); if(n > p->len) abort(); return p->data + p->len - n; } int packettrim(Packet *p, int offset, int n) { NOTFREE(p); if(offset < 0 || n < 0) abort(); if(offset+n > p->len) abort(); memmove(p->data+offset, p->data+offset+n, p->len-offset-n); p->len -= n; return 0; }