* - MPI convenience functions
*/
/*
- * This file is
- * Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
+ * This file is part of secnet.
+ * See README for full list of copyright holders.
*
- * It is part of secnet, which is
- * Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
- * Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * secnet is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * secnet is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 3 along with secnet; if not, see
+ * https://www.gnu.org/licenses/gpl.html.
*/
#include "secnet.h"
#include <limits.h>
#include <assert.h>
#include <sys/wait.h>
+#include <adns.h>
#include "util.h"
#include "unaligned.h"
+#include "magic.h"
+#include "ipaddr.h"
#define MIN_BUFFER_SIZE 64
#define DEFAULT_BUFFER_SIZE 4096
struct phase_hook {
hook_fn *fn;
void *state;
- struct phase_hook *next;
+ LIST_ENTRY(phase_hook) entry;
};
-static struct phase_hook *hooks[NR_PHASES]={NULL,};
+static LIST_HEAD(, phase_hook) hooks[NR_PHASES];
char *safe_strdup(const char *s, const char *message)
{
char *d;
d=strdup(s);
if (!d) {
- fatal_perror(message);
+ fatal_perror("%s",message);
}
return d;
}
void *safe_malloc(size_t size, const char *message)
{
void *r;
+ if (!size)
+ return 0;
r=malloc(size);
if (!r) {
- fatal_perror(message);
+ fatal_perror("%s",message);
}
return r;
}
-void *safe_malloc_ary(size_t size, size_t count, const char *message) {
+void *safe_realloc_ary(void *p, size_t size, size_t count,
+ const char *message) {
if (count >= INT_MAX/size) {
fatal("array allocation overflow: %s", message);
}
- return safe_malloc(size*count, message);
+ assert(size && count);
+ p = realloc(p, size*count);
+ if (!p)
+ fatal_perror("%s", message);
+ return p;
}
-/* Convert a buffer into its MP_INT representation */
-void read_mpbin(MP_INT *a, uint8_t *bin, int binsize)
+void *safe_malloc_ary(size_t size, size_t count, const char *message) {
+ if (!size || !count)
+ return 0;
+ return safe_realloc_ary(0,size,count,message);
+}
+
+void hex_encode(const uint8_t *bin, int binsize, char *buff)
{
- char *buff;
int i;
- buff=safe_malloc(binsize*2 + 1,"read_mpbin");
-
for (i=0; i<binsize; i++) {
buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4];
buff[i*2+1]=hexdigits[(bin[i] & 0xf)];
}
buff[binsize*2]=0;
-
- mpz_set_str(a, buff, 16);
- free(buff);
}
-/* Convert a MP_INT into a hex string */
-char *write_mpstring(MP_INT *a)
+string_t hex_encode_alloc(const uint8_t *bin, int binsize)
{
char *buff;
- buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring");
- mpz_get_str(buff, 16, a);
+ buff=safe_malloc(hex_encode_size(binsize),"hex_encode");
+ hex_encode(bin,binsize,buff);
return buff;
}
return -1;
}
-/* Convert a MP_INT into a buffer; return length; truncate if necessary */
-uint32_t write_mpbin(MP_INT *a, uint8_t *buffer, uint32_t buflen)
+bool_t hex_decode(uint8_t *buffer, int32_t buflen, int32_t *outlen,
+ cstring_t hb, bool_t allow_odd_nibble)
{
- char *hb;
- int i,j,l;
-
- if (buflen==0) return 0;
- hb=write_mpstring(a);
-
- l=strlen(hb);
- i=0; j=0;
+ int i = 0, j = 0, l = strlen(hb), hi, lo;
+ bool_t ok = False;
+
+ if (!l || !buflen) { ok = !l; goto done; }
if (l&1) {
/* The number starts with a half-byte */
- buffer[i++]=hexval(hb[j++]);
+ if (!allow_odd_nibble) goto done;
+ lo = hexval(hb[j++]); if (lo < 0) goto done;
+ buffer[i++] = lo;
}
- for (; hb[j] && i<buflen; i++) {
- buffer[i]=(hexval(hb[j])<<4)|hexval(hb[j+1]);
- j+=2;
+ for (; hb[j] && i < buflen; i++) {
+ hi = hexval(hb[j++]);
+ lo = hexval(hb[j++]);
+ if (hi < 0 || lo < 0) goto done;
+ buffer[i] = (hi << 4) | lo;
}
+ ok = !hb[j];
+done:
+ *outlen = i;
+ return ok;
+}
+
+void read_mpbin(MP_INT *a, uint8_t *bin, int binsize)
+{
+ char *buff = hex_encode_alloc(bin, binsize);
+ mpz_set_str(a, buff, 16);
+ free(buff);
+}
+
+char *write_mpstring(MP_INT *a)
+{
+ char *buff;
+
+ buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring");
+ mpz_get_str(buff, 16, a);
+ return buff;
+}
+
+int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen)
+{
+ char *hb = write_mpstring(a);
+ int32_t len;
+ hex_decode(buffer, buflen, &len, hb, True);
free(hb);
- return i;
+ return len;
+}
+
+#define DEFINE_SETFDFLAG(fn,FL,FLAG) \
+void fn(int fd) { \
+ int r=fcntl(fd, F_GET##FL); \
+ if (r<0) fatal_perror("fcntl(,F_GET" #FL ") failed"); \
+ r=fcntl(fd, F_SET##FL, r|FLAG); \
+ if (r<0) fatal_perror("fcntl(,F_SET" #FL ",|" #FLAG ") failed"); \
+}
+
+DEFINE_SETFDFLAG(setcloexec,FD,FD_CLOEXEC);
+DEFINE_SETFDFLAG(setnonblock,FL,O_NONBLOCK);
+
+void pipe_cloexec(int fd[2]) {
+ int r=pipe(fd);
+ if (r) fatal_perror("pipe");
+ setcloexec(fd[0]);
+ setcloexec(fd[1]);
}
static const char *phases[NR_PHASES]={
"PHASE_GETOPTS",
"PHASE_READCONFIG",
"PHASE_SETUP",
+ "PHASE_DAEMONIZE",
"PHASE_GETRESOURCES",
"PHASE_DROPPRIV",
"PHASE_RUN",
- "PHASE_SHUTDOWN"
+ "PHASE_SHUTDOWN",
+ "PHASE_CHILDPERSIST"
};
void enter_phase(uint32_t new_phase)
{
struct phase_hook *i;
- if (hooks[new_phase])
+ if (!LIST_EMPTY(&hooks[new_phase]))
Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]);
current_phase=new_phase;
- for (i=hooks[new_phase]; i; i=i->next)
+ LIST_FOREACH(i, &hooks[new_phase], entry)
i->fn(i->state, new_phase);
Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]);
}
+void phase_hooks_init(void)
+{
+ int i;
+ for (i=0; i<NR_PHASES; i++)
+ LIST_INIT(&hooks[i]);
+}
+
+void clear_phase_hooks(uint32_t phase)
+{
+ struct phase_hook *h, *htmp;
+ LIST_FOREACH_SAFE(h, &hooks[phase], entry, htmp)
+ free(h);
+ LIST_INIT(&hooks[phase]);
+}
+
bool_t add_hook(uint32_t phase, hook_fn *fn, void *state)
{
struct phase_hook *h;
- h=safe_malloc(sizeof(*h),"add_hook");
+ NEW(h);
h->fn=fn;
h->state=state;
- h->next=hooks[phase];
- hooks[phase]=h;
+ LIST_INSERT_HEAD(&hooks[phase],h,entry);
return True;
}
void vslilog(struct log_if *lf, int priority, const char *message, va_list ap)
{
- lf->vlog(lf->st,priority,message,ap);
+ lf->vlogfn(lf->st,priority,message,ap);
}
void slilog(struct log_if *lf, int priority, const char *message, ...)
};
void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
- uint32_t line)
+ int line)
{
if (!buffer->free) {
- fatal("BUF_ASSERT_FREE, %s line %d, owned by %s",
- file,line,buffer->owner);
+ fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s",
+ file,line,buffer->owner);
+ assert(!"buffer_assert_free failure");
}
}
void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
- uint32_t line)
+ int line)
{
if (buffer->free) {
- fatal("BUF_ASSERT_USED, %s line %d, last owned by %s",
- file,line,buffer->owner);
+ fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s",
+ file,line,buffer->owner);
+ assert(!"buffer_assert_used failure");
}
}
-void buffer_init(struct buffer_if *buffer, uint32_t max_start_pad)
+void buffer_init(struct buffer_if *buffer, int32_t max_start_pad)
{
+ assert(max_start_pad<=buffer->alloclen);
buffer->start=buffer->base+max_start_pad;
buffer->size=0;
}
-void *buf_append(struct buffer_if *buf, uint32_t amount) {
+void buffer_destroy(struct buffer_if *buf)
+{
+ BUF_ASSERT_FREE(buf);
+ free(buf->base);
+ buf->start=buf->base=0;
+ buf->size=buf->alloclen=0;
+}
+
+void *buf_append(struct buffer_if *buf, int32_t amount) {
void *p;
- assert(buf->size <= buf->len - amount);
+ assert(amount <= buf_remaining_space(buf));
p=buf->start + buf->size;
buf->size+=amount;
return p;
}
-void *buf_prepend(struct buffer_if *buf, uint32_t amount) {
+void *buf_prepend(struct buffer_if *buf, int32_t amount) {
assert(amount <= buf->start - buf->base);
buf->size+=amount;
return buf->start-=amount;
}
-void *buf_unappend(struct buffer_if *buf, uint32_t amount) {
+void *buf_unappend(struct buffer_if *buf, int32_t amount) {
if (buf->size < amount) return 0;
return buf->start+(buf->size-=amount);
}
-void *buf_unprepend(struct buffer_if *buf, uint32_t amount) {
+void *buf_unprepend(struct buffer_if *buf, int32_t amount) {
void *p;
+ if (buf->size < amount) return 0;
p=buf->start;
buf->start+=amount;
buf->size-=amount;
return p;
}
-/* Append a two-byte length and the string to the buffer. Length is in
- network byte order. */
void buf_append_string(struct buffer_if *buf, cstring_t s)
{
- uint16_t len;
+ size_t len;
len=strlen(s);
/* fixme: if string is longer than 65535, result is a corrupted packet */
buf_append_uint16(buf,len);
- memcpy(buf_append(buf,len),s,len);
+ BUF_ADD_BYTES(append,buf,s,len);
+}
+
+void truncmsg_add_string(struct buffer_if *buf, cstring_t s)
+{
+ int32_t l = MIN((int32_t)strlen(s), buf_remaining_space(buf));
+ BUF_ADD_BYTES(append, buf, s, l);
+}
+void truncmsg_add_packet_string(struct buffer_if *buf, int32_t l,
+ const uint8_t *s)
+{
+ char c;
+ while (l-- > 0) {
+ c = *s++;
+ if (c >= ' ' && c <= 126 && c != '\\' && c != '"' && c != '\'') {
+ if (!buf_remaining_space(buf)) break;
+ buf->start[buf->size++] = c;
+ continue;
+ }
+ char quoted[5];
+ quoted[0] = '\\';
+ quoted[2] = 0;
+ switch (c) {
+ case '\n': quoted[1] = 'n'; break;
+ case '\r': quoted[1] = 'r'; break;
+ case '\t': quoted[1] = 't'; break;
+ case '\\': case '"': case '\'': quoted[1] = c; break;
+ default: sprintf(quoted, "\\x%02x", (unsigned)c);
+ }
+ truncmsg_add_string(buf, quoted);
+ }
+}
+const char *truncmsg_terminate(const struct buffer_if *buf)
+{
+ if (buf_remaining_space(buf)) {
+ buf->start[buf->size] = 0;
+ } else {
+ assert(buf->size >= 4);
+ strcpy(buf->start + buf->size - 4, "...");
+ }
+ return buf->start;
+}
+
+void priomsg_new(struct priomsg *pm, int32_t maxlen)
+{
+ buffer_new(&pm->m, maxlen);
+ pm->prio = INT_MIN;
+}
+void priomsg_reset(struct priomsg *pm)
+{
+ buffer_init(&pm->m, 0);
+ pm->prio = INT_MIN;
+}
+bool_t priomsg_update_p(struct priomsg *pm, int prio)
+{
+ if (!pm) return False;
+ if (prio <= pm->prio) return False;
+ buffer_init(&pm->m, 0);
+ pm->prio = prio;
+ return True;
+}
+const char *priomsg_getmessage(const struct priomsg *pm, const char *defmsg)
+{
+ if (pm->prio >= INT_MIN)
+ return truncmsg_terminate(&pm->m);
+ else
+ return defmsg;
}
-void buffer_new(struct buffer_if *buf, uint32_t len)
+bool_t priomsg_update_fixed(struct priomsg *pm, int prio, const char *m) {
+ if (!priomsg_update_p(pm, prio)) return False;
+ truncmsg_add_string(&pm->m, m);
+ return True;
+}
+
+void buffer_new(struct buffer_if *buf, int32_t len)
{
buf->free=True;
buf->owner=NULL;
- buf->flags=0;
buf->loc.file=NULL;
buf->loc.line=0;
buf->size=0;
- buf->len=len;
+ buf->alloclen=len;
buf->start=NULL;
buf->base=safe_malloc(len,"buffer_new");
}
+void buffer_readonly_view(struct buffer_if *buf, const void *data, int32_t len)
+{
+ buf->free=False;
+ buf->owner="READONLY";
+ buf->loc.file=NULL;
+ buf->loc.line=0;
+ buf->size=buf->alloclen=len;
+ buf->base=buf->start=(uint8_t*)data;
+}
+
+void buffer_readonly_clone(struct buffer_if *out, const struct buffer_if *in)
+{
+ buffer_readonly_view(out,in->start,in->size);
+}
+
+void buffer_copy(struct buffer_if *dst, const struct buffer_if *src)
+{
+ if (dst->alloclen < src->alloclen) {
+ dst->base=realloc(dst->base,src->alloclen);
+ if (!dst->base) fatal_perror("buffer_copy");
+ dst->alloclen = src->alloclen;
+ }
+ dst->start = dst->base + (src->start - src->base);
+ dst->size = src->size;
+ memcpy(dst->start, src->start, dst->size);
+}
+
static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
list_t *args)
{
bool_t lockdown=False;
uint32_t len=DEFAULT_BUFFER_SIZE;
- st=safe_malloc(sizeof(*st),"buffer_apply");
+ NEW(st);
st->cl.description="buffer";
st->cl.type=CL_BUFFER;
st->cl.apply=NULL;
return new_closure(&st->cl);
}
+void send_nak(const struct comm_addr *dest, uint32_t our_index,
+ uint32_t their_index, uint32_t msgtype,
+ struct buffer_if *buf, const char *logwhy)
+{
+ buffer_init(buf,calculate_max_start_pad());
+ buf_append_uint32(buf,their_index);
+ buf_append_uint32(buf,our_index);
+ buf_append_uint32(buf,LABEL_NAK);
+ if (logwhy)
+ Message(M_INFO,"%s: sending NAK for"
+ " %08"PRIx32" %08"PRIx32"<-%08"PRIx32":"
+ " %s\n",
+ comm_addr_to_string(dest),
+ msgtype, our_index, their_index, logwhy);
+ dest->comm->sendmsg(dest->comm->st, buf, dest, 0);
+}
+
+int consttime_memeq(const void *s1in, const void *s2in, size_t n)
+{
+ const uint8_t *s1=s1in, *s2=s2in;
+ register volatile uint8_t accumulator=0;
+
+ while (n-- > 0) {
+ accumulator |= (*s1++ ^ *s2++);
+ }
+ accumulator |= accumulator >> 4; /* constant-time */
+ accumulator |= accumulator >> 2; /* boolean canonicalisation */
+ accumulator |= accumulator >> 1;
+ accumulator &= 1;
+ accumulator ^= 1;
+ return accumulator;
+}
+
+void hash_hash(const struct hash_if *hashi, const void *msg, int32_t len,
+ uint8_t *digest) {
+ uint8_t hst[hashi->slen];
+ hashi->init(hst);
+ hashi->update(hst,msg,len);
+ hashi->final(hst,digest);
+}
+
void util_module(dict_t *dict)
{
add_closure(dict,"sysbuffer",buffer_apply);
}
+
+void update_max_start_pad(int32_t *our_module_global, int32_t our_instance)
+{
+ if (*our_module_global < our_instance)
+ *our_module_global=our_instance;
+}
+
+int32_t transform_max_start_pad, comm_max_start_pad;
+
+int32_t calculate_max_start_pad(void)
+{
+ return
+ site_max_start_pad +
+ transform_max_start_pad +
+ comm_max_start_pad;
+}
+
+void vslilog_part(struct log_if *lf, int priority, const char *message, va_list ap)
+{
+ char *buff=lf->buff;
+ size_t bp;
+ char *nlp;
+
+ bp=strlen(buff);
+ assert(bp < LOG_MESSAGE_BUFLEN);
+ vsnprintf(buff+bp,LOG_MESSAGE_BUFLEN-bp,message,ap);
+ buff[LOG_MESSAGE_BUFLEN-1] = '\n';
+ buff[LOG_MESSAGE_BUFLEN] = '\0';
+ /* Each line is sent separately */
+ while ((nlp=strchr(buff,'\n'))) {
+ *nlp=0;
+ slilog(lf,priority,"%s",buff);
+ memmove(buff,nlp+1,strlen(nlp+1)+1);
+ }
+}
+
+extern void slilog_part(struct log_if *lf, int priority, const char *message, ...)
+{
+ va_list ap;
+ va_start(ap,message);
+ vslilog_part(lf,priority,message,ap);
+ va_end(ap);
+}
+
+void string_item_to_iaddr(const item_t *item, uint16_t port, union iaddr *ia,
+ const char *desc)
+{
+#ifndef CONFIG_IPV6
+
+ ia->sin.sin_family=AF_INET;
+ ia->sin.sin_addr.s_addr=htonl(string_item_to_ipaddr(item,desc));
+ ia->sin.sin_port=htons(port);
+
+#else /* CONFIG_IPV6 => we have adns_text2addr */
+
+ if (item->type!=t_string)
+ cfgfatal(item->loc,desc,"expecting a string IP (v4 or v6) address\n");
+ socklen_t salen=sizeof(*ia);
+ int r=adns_text2addr(item->data.string, port,
+ adns_qf_addrlit_ipv4_quadonly,
+ &ia->sa, &salen);
+ assert(r!=ENOSPC);
+ if (r) cfgfatal(item->loc,desc,"invalid IP (v4 or v6) address: %s\n",
+ strerror(r));
+
+#endif /* CONFIG_IPV6 */
+}
+
+#define IADDR_NBUFS 8
+
+const char *iaddr_to_string(const union iaddr *ia)
+{
+#ifndef CONFIG_IPV6
+
+ SBUF_DEFINE(IADDR_NBUFS, 100);
+
+ assert(ia->sa.sa_family == AF_INET);
+
+ snprintf(SBUF, sizeof(SBUF), "[%s]:%d",
+ inet_ntoa(ia->sin.sin_addr),
+ ntohs(ia->sin.sin_port));
+
+#else /* CONFIG_IPV6 => we have adns_addr2text */
+
+ SBUF_DEFINE(IADDR_NBUFS, 1+ADNS_ADDR2TEXT_BUFLEN+20);
+
+ int port;
+
+ char *addrbuf = SBUF;
+ *addrbuf++ = '[';
+ int addrbuflen = ADNS_ADDR2TEXT_BUFLEN;
+
+ int r = adns_addr2text(&ia->sa, 0, addrbuf, &addrbuflen, &port);
+ if (r) {
+ const char fmt[]= "bad addr, error: %.*s";
+ sprintf(addrbuf, fmt,
+ (int)(ADNS_ADDR2TEXT_BUFLEN - sizeof(fmt)) /* underestimate */,
+ strerror(r));
+ }
+
+ char *portbuf = addrbuf;
+ int addrl = strlen(addrbuf);
+ portbuf += addrl;
+
+ snprintf(portbuf, sizeof(SBUF)-addrl, "]:%d", port);
+
+#endif /* CONFIG_IPV6 */
+
+ return SBUF;
+}
+
+bool_t iaddr_equal(const union iaddr *ia, const union iaddr *ib,
+ bool_t ignoreport)
+{
+ if (ia->sa.sa_family != ib->sa.sa_family)
+ return 0;
+ switch (ia->sa.sa_family) {
+ case AF_INET:
+ return ia->sin.sin_addr.s_addr == ib->sin.sin_addr.s_addr
+ && (ignoreport ||
+ ia->sin.sin_port == ib->sin.sin_port);
+#ifdef CONFIG_IPV6
+ case AF_INET6:
+ return !memcmp(&ia->sin6.sin6_addr, &ib->sin6.sin6_addr, 16)
+ && ia->sin6.sin6_scope_id == ib->sin6.sin6_scope_id
+ && (ignoreport ||
+ ia->sin6.sin6_port == ib->sin6.sin6_port)
+ /* we ignore the flowinfo field */;
+#endif /* CONFIG_IPV6 */
+ default:
+ abort();
+ }
+}
+
+int iaddr_socklen(const union iaddr *ia)
+{
+ switch (ia->sa.sa_family) {
+ case AF_INET: return sizeof(ia->sin);
+#ifdef CONFIG_IPV6
+ case AF_INET6: return sizeof(ia->sin6);
+#endif /* CONFIG_IPV6 */
+ default: abort();
+ }
+}
+
+const char *pollbadbit(int revents)
+{
+#define BADBIT(b) \
+ if ((revents & b)) return #b
+ BADBIT(POLLERR);
+ BADBIT(POLLHUP);
+ /* POLLNVAL is handled by the event loop - see afterpoll_fn comment */
+#undef BADBIT
+ return 0;
+}
+
+void pathprefix_template_init(struct pathprefix_template *out,
+ const char *prefix, int maxsuffix)
+{
+ size_t l=strlen(prefix);
+ NEW_ARY(out->buffer,l+maxsuffix+1);
+ strcpy(out->buffer,prefix);
+ out->write_here=out->buffer+l;
+}
+
+enum async_linebuf_result
+async_linebuf_read(struct pollfd *pfd, struct buffer_if *buf,
+ const char **emsg_out)
+{
+ int revents=pfd->revents;
+
+#define BAD(m) do{ *emsg_out=(m); return async_linebuf_broken; }while(0)
+
+ const char *badbit=pollbadbit(revents);
+ if (badbit) BAD(badbit);
+
+ if (!(revents & POLLIN))
+ return async_linebuf_nothing;
+
+ /*
+ * Data structure: A line which has been returned to the user is
+ * stored in buf at base before start. But we retain the usual
+ * buffer meaning of size. So:
+ *
+ * | returned : | input read, | unused |
+ * | to user : \0 | awaiting | buffer |
+ * | : | processing | space |
+ * | : | | |
+ * ^base ^start ^start+size ^base+alloclen
+ */
+
+ BUF_ASSERT_USED(buf);
+
+ /* firstly, eat any previous */
+ if (buf->start != buf->base) {
+ memmove(buf->base,buf->start,buf->size);
+ buf->start=buf->base;
+ }
+
+ uint8_t *searched=buf->base;
+
+ /*
+ * During the workings here we do not use start. We set start
+ * when we return some actual data. So we have this:
+ *
+ * | searched | read, might | unused |
+ * | for \n | contain \n | buffer |
+ * | none found | but not \0 | space |
+ * | | | |
+ * ^base ^searched ^base+size ^base+alloclen
+ * [^start] ^dataend
+ *
+ */
+ for (;;) {
+ uint8_t *dataend=buf->base+buf->size;
+ char *newline=memchr(searched,'\n',dataend-searched);
+ if (newline) {
+ *newline=0;
+ buf->start=newline+1;
+ buf->size=dataend-buf->start;
+ return async_linebuf_ok;
+ }
+ searched=dataend;
+ ssize_t space=(buf->base+buf->alloclen)-dataend;
+ if (!space) BAD("input line too long");
+ ssize_t r=read(pfd->fd,searched,space);
+ if (r==0) {
+ *searched=0;
+ *emsg_out=buf->size?"no newline at eof":0;
+ buf->start=searched+1;
+ buf->size=0;
+ return async_linebuf_eof;
+ }
+ if (r<0) {
+ if (errno==EINTR)
+ continue;
+ if (iswouldblock(errno))
+ return async_linebuf_nothing;
+ BAD(strerror(errno));
+ }
+ assert(r<=space);
+ if (memchr(searched,0,r)) BAD("nul in input data");
+ buf->size+=r;
+ }
+
+#undef BAD
+}