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#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/mman.h>
#include <errno.h>
#include <netinet/in.h>
#include <string.h>
#include <ctype.h>
static int protofd=-1;
static char* protomap;
static unsigned int protolen;
static char* aliases[10];
static char *cur;
/* ip 0 IP # internet protocol, pseudo protocol number */
struct protoent *getprotoent(void) {
static struct protoent pe;
char *last;
int aliasidx;
if (protofd<0) {
protofd=open(_PATH_SERVICES,O_RDONLY);
if (protofd<0) return 0;
protolen=lseek(protofd,0,SEEK_END);
protomap=mmap(0,protolen,PROT_READ|PROT_WRITE,MAP_PRIVATE,protofd,0);
if ((long)protomap==(-1)) goto error;
cur=protomap;
}
last=protomap+protolen;
again:
pe.p_name=0;
pe.p_aliases=aliases; aliases[0]=0;
pe.p_proto=0;
if (cur>=last) return 0;
if (*cur=='#' || *cur=='\n') goto parseerror;
/* first, the primary name */
if (!isalpha(*cur)) goto parseerror;
pe.p_name=cur;
pe.p_aliases=aliases;
while (cur<last && isalnum(*cur)) cur++;
if (cur>=last) return 0;
if (*cur=='\n') goto parseerror;
*cur=0; cur++;
/* second, the protocol number */
while (cur<last && isblank(*cur)) cur++;
while (cur<last && isdigit(*cur)) {
pe.p_proto=pe.p_proto*10+*cur-'0';
cur++;
}
/* pe.p_proto=htons(pe.s_proto); */
if (cur>=last) return 0;
if (*cur=='\n') { *cur++=0; return &pe; }
*cur=0; cur++;
/* now the aliases */
for (aliasidx=0;aliasidx<10;++aliasidx) {
while (cur<last && isblank(*cur)) ++cur;
aliases[aliasidx]=cur;
while (cur<last && isalpha(*cur)) ++cur;
if (*cur=='\n') { *cur++=0; ++aliasidx; break; }
if (cur>=last || !isblank(*cur)) break;
*cur++=0;
}
aliases[aliasidx]=0;
return &pe;
parseerror:
while (cur<last && *cur!='\n') cur++;
cur++;
goto again;
error:
if (protomap!=(char*)-1) munmap(protomap,protolen);
if (protofd!=-1) close(protofd);
protomap=(char*)-1;
protofd=-1;
errno=ENOMEM;
return 0;
}
void setprotoent(int stayopen) {
cur=protomap;
}
struct protoent *getprotobyname(const char *name) {
struct protoent *s;
setprotoent(0);
for (s=getprotoent(); s; s=getprotoent()) {
char **tmp;
#if 0
write(1,"found ",6);
write(1,s->p_name,strlen(s->p_name));
write(1,"/",1);
write(1,s->p_proto,strlen(s->p_proto));
write(1,"\n",1);
if (!strcmp(name,"auth")) {
tmp=s->p_aliases;
write(1," aka ",5);
while (*tmp) {
write(1,*tmp,strlen(*tmp));
write(1,", ",2);
++tmp;
}
write(1,"\n",1);
}
#endif
if (!strcmp(name,s->p_name))
return s;
tmp=s->p_aliases;
while (*tmp)
if (!strcmp(name,*tmp++)) return s;
}
return 0;
}
struct protoent *getprotobynumber(int proto) {
struct protoent *s;
for (s=getprotoent(); s; s=getprotoent()) {
if (proto==s->p_proto)
return s;
}
return 0;
}
void endprotoent(void) {
if (protomap!=(char*)-1) munmap(protomap,protolen);
if (protofd!=-1) close(protofd);
protomap=(char*)-1;
protofd=-1;
}
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