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ircservices5/sockets.c
Koragg ee2108e123
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2019-01-23 09:42:02 +01:00

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/* Socket routines.
*
* IRC Services is copyright (c) 1996-2009 Andrew Church.
* E-mail: <achurch@achurch.org>
* Parts written by Andrew Kempe and others.
* This program is free but copyrighted software; see the file GPL.txt for
* details.
*/
/* Define this to trace function calls: */
/* #define TRACE_CALLS */
/* Define this to log warnings on exceeding buffer size: */
/* #define WARN_ON_BUFSIZE */
/* Define this to disable swritemap(). For IRC Services, we disable this
* to avoid depending on the presence of munmap(), since we don't use
* swritemap() anyway. */
#define DISABLE_SWRITEMAP
#include "services.h"
#include <fcntl.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifndef DISABLE_SWRITEMAP
# include <sys/mman.h> /* for munmap() */
#endif
/*************************************************************************/
/* For function call tracing: */
#ifdef TRACE_CALLS
static int trace_depth = -1;
#define ENTER(fmt,...) \
trace_depth++; \
log_debug(1, "sockets: TRACE: %*s%s(" fmt ")", \
trace_depth*2, "", __FUNCTION__ , ## __VA_ARGS__)
#define ENTER_WITH(retfmt,fmt,...) \
const char *__retfmt = (retfmt); \
ENTER(fmt , ## __VA_ARGS__)
#define RETURN do { \
log_debug(1, "sockets: TRACE: %*s%s() -> void", \
trace_depth*2, "", __FUNCTION__); \
trace_depth--; \
return; \
} while (0)
#define RETURN_WITH(val) do { \
typeof(val) __tmp = (val); \
if (debug) { \
char buf[64]; \
snprintf(buf, sizeof(buf), __retfmt, __tmp); \
log_debug(1, "sockets: TRACE: %*s%s() -> %s", \
trace_depth*2, "", __FUNCTION__, buf); \
} \
trace_depth--; \
return __tmp; \
} while (0)
#else /* !TRACE_CALLS */
#define ENTER(fmt,...) /* nothing */
#define ENTER_WITH(retfmt,fmt,...) /* nothing */
#define RETURN return
#define RETURN_WITH(val) return(val)
#endif /* TRACE_CALLS */
/*************************************************************************/
/* Socket data structure */
struct socket_ {
Socket *next, *prev;
int fd; /* Socket's file descriptor */
struct sockaddr_in remote; /* Remote address */
int flags; /* Status flags (SF_*) */
SocketCallback cb_connect; /* Connect callback */
SocketCallback cb_disconn; /* Disconnect callback */
SocketCallback cb_accept; /* Accept callback */
SocketCallback cb_read; /* Data-available callback */
SocketCallback cb_readline; /* Line-available callback */
SocketCallback cb_trigger; /* Write trigger callback */
int write_timeout; /* Write timeout, in seconds (0 = none) */
time_t last_write_time; /* Last time data was successfully sent */
/* Usage of pointers:
* - Xbuf is the buffer base pointer
* - Xptr is the address of the next character to store
* - Xend is the address of the next character to retrieve
* - Xtop is the address of the last byte of the buffer + 1
* Xend-Xptr (mod Xbufsize) gives the number of bytes in the buffer.
*/
char *rbuf, *rptr, *rend, *rtop; /* Read buffer and pointers */
char *wbuf, *wptr, *wend, *wtop; /* Write buffer and pointers */
/* List of mapped memory areas to send, earliest first */
struct wmapinfo {
struct wmapinfo *next;
int32 wait; /* # of bytes to write from wbuf first */
const char *map; /* Start of mapped area, or trigger data */
int32 maplen; /* Length of mapped area (0 = write trigger) */
int32 pos; /* Current position */
} *writemap, *writemap_tail;
uint64 total_read; /* Total number of bytes read */
uint64 total_written; /* Total number of bytes written */
};
#define SF_SELFCREATED 0x0001 /* We created this socket ourselves */
#define SF_BLOCKING 0x0002 /* Writes are blocking */
#define SF_LISTENER 0x0004 /* Socket is a listener socket */
#define SF_CONNECTING 0x0008 /* Socket is busy connecting */
#define SF_CONNECTED 0x0010 /* Socket has connected */
#define SF_MUTE 0x0020 /* Socket is muted */
#define SF_UNMUTED 0x0040 /* Socket was just unmuted */
#define SF_CALLBACK 0x0080 /* Currently calling callbacks */
#define SF_WTRIGGER 0x0100 /* A write trigger has been reached */
#define SF_WARNED 0x0200 /* Warned about hitting buffer limit */
#define SF_DISCONNECT 0x0400 /* Disconnect when writebuf empty */
#define SF_DISCONN_REQ 0x0800 /* Disconnect has been requested */
#define SF_DISCONNECTING 0x1000 /* Socket is in the middle of disconnecting */
#define SF_BROKEN 0x2000 /* Connection was broken while in a callback */
#define SF_DELETEME 0x4000 /* Delete socket when convenient */
/* Used when calling do_disconn() due to SF_DISCONNECT */
#define DISCONN_RESUME_FLAG 0x100
#define DISCONN_LOCAL_RESUME (void *)((int)DISCONN_LOCAL|DISCONN_RESUME_FLAG)
#define DISCONN_REMOTE_RESUME (void *)((int)DISCONN_REMOTE|DISCONN_RESUME_FLAG)
/* Size of read/write buffers */
#define read_buffer_size(s) ((s)->rtop - (s)->rbuf)
#define write_buffer_size(s) ((s)->wtop - (s)->wbuf)
/* Does the socket still have more data that needs to be written? */
#define MORE_TO_WRITE(s) (write_buffer_len(s) > 0 || ((s)->writemap))
/*************************************************************************/
/* List of all sockets (even unopened ones) */
static Socket *allsockets = NULL;
/* Array of all opened sockets (indexed by FD), dynamically allocated */
static Socket **sockets = NULL;
/* Highest FD number in use plus 1; also length of sockets[] array */
static int max_fd;
/* Set of all connected socket FDs */
static fd_set sock_fds;
/* Set of all FDs that need data written (or are connecting) */
static fd_set write_fds;
/* Total memory used by socket buffers */
static uint32 total_bufsize;
/* Per-connection and total buffer size limits */
static uint32 bufsize_limit = 0, total_bufsize_limit = 0;
/* Global read timeout, in milliseconds */
static int read_timeout = -1;
/*************************************************************************/
/* Internal routine declarations (definitions at bottom of file) */
static int do_callback(Socket *s, SocketCallback cb, void *param);
static void do_accept(Socket *s);
static int fill_read_buffer(Socket *s);
static int flush_write_buffer(Socket *s);
static uint32 resize_how_much(const Socket *s, uint32 current_size, int *errp);
static int resize_rbuf(Socket *s, uint32 size);
static int resize_wbuf(Socket *s, uint32 size);
static int resize_buf(char **p_buf, char **p_ptr, char **p_end, char **p_top,
uint32 newsize);
static int reclaim_buffer_space_one(Socket *s);
static int reclaim_buffer_space(void);
static void next_wmap(Socket *s);
static int buffered_write(Socket *s, const char *buf, int len);
static int do_disconn(Socket *s, void *code);
static void sock_closefd(Socket *s);
/*************************************************************************/
/*************************** Global routines *****************************/
/*************************************************************************/
/* Set the per-connection and total buffer size limits (zero means no
* limit). Always successful; both values are silently rounded down to a
* multiple of SOCK_MIN_BUFSIZE (if a value is less than SOCK_MIN_BUFSIZE it
* is rounded up). Both values default to zero, i.e. unlimited.
*/
void sock_set_buflimits(uint32 per_conn, uint32 total)
{
if (per_conn > 0) {
per_conn = per_conn / SOCK_MIN_BUFSIZE * SOCK_MIN_BUFSIZE;
if (!per_conn)
per_conn = SOCK_MIN_BUFSIZE;
}
if (total > 0) {
total = total / SOCK_MIN_BUFSIZE * SOCK_MIN_BUFSIZE;
if (!total)
total = SOCK_MIN_BUFSIZE;
}
bufsize_limit = per_conn;
total_bufsize_limit = total;
}
/*************************************************************************/
/* Set the global read timeout. A value of -1 (default) means no timeout. */
void sock_set_rto(int msec)
{
read_timeout = msec;
}
/*************************************************************************/
/* Create and return a new socket. Returns NULL if unsuccessful (i.e. no
* more space for buffers).
*/
Socket *sock_new(void)
{
Socket *s;
ENTER_WITH("%p", "");
if (total_bufsize_limit) {
while (total_bufsize + SOCK_MIN_BUFSIZE*2 > total_bufsize_limit) {
if (!reclaim_buffer_space()) {
log("sockets: sock_new(): out of buffer space! current=%lu,"
" limit=%lu", (unsigned long)total_bufsize,
(unsigned long)total_bufsize_limit);
RETURN_WITH(NULL);
}
}
}
s = malloc(sizeof(*s));
if (!s) {
RETURN_WITH(NULL);
}
s->rbuf = malloc(SOCK_MIN_BUFSIZE);
if (!s->rbuf) {
int errno_save = errno;
free(s);
errno = errno_save;
RETURN_WITH(NULL);
}
s->wbuf = malloc(SOCK_MIN_BUFSIZE);
if (!s->wbuf) {
int errno_save = errno;
free(s->rbuf);
free(s);
errno = errno_save;
RETURN_WITH(NULL);
}
s->fd = -1;
memset(&s->remote, 0, sizeof(s->remote));
s->flags = 0;
s->cb_connect = NULL;
s->cb_disconn = NULL;
s->cb_accept = NULL;
s->cb_read = NULL;
s->cb_readline = NULL;
s->cb_trigger = NULL;
s->write_timeout = 0;
s->last_write_time = time(NULL);
s->rptr = s->rbuf;
s->rend = s->rbuf;
s->rtop = s->rbuf + SOCK_MIN_BUFSIZE;
s->wptr = s->wbuf;
s->wend = s->wbuf;
s->wtop = s->wbuf + SOCK_MIN_BUFSIZE;
s->writemap = NULL;
s->writemap_tail = NULL;
s->total_read = 0;
s->total_written = 0;
LIST_INSERT(s, allsockets);
total_bufsize += read_buffer_size(s) + write_buffer_size(s);
RETURN_WITH(s);
}
/*************************************************************************/
/* Free a socket, first disconnecting/closing it if necessary. */
void sock_free(Socket *s)
{
ENTER("%p", s);
if (!s) {
log("sockets: sock_free() with NULL socket!");
errno = EINVAL;
RETURN;
}
if (s->flags & (SF_CONNECTING | SF_CONNECTED)) {
s->flags |= SF_DELETEME;
do_disconn(s, DISCONN_LOCAL);
/* do_disconn() will call us again at the appropriate time */
RETURN;
} else if (s->flags & SF_LISTENER) {
close_listener(s);
}
LIST_REMOVE(s, allsockets);
total_bufsize -= read_buffer_size(s) + write_buffer_size(s);
free(s->rbuf);
free(s->wbuf);
free(s);
/* If this was the last socket, free the sockets[] array too */
if (!allsockets) {
free(sockets);
sockets = NULL;
}
RETURN;
}
/*************************************************************************/
/* Set a callback on a socket. */
void sock_setcb(Socket *s, SocketCallbackID which, SocketCallback func)
{
ENTER("%p,%d,%p", s, which, func);
if (!s) {
log("sockets: sock_setcb() with NULL socket!");
errno = EINVAL;
RETURN;
}
switch (which) {
case SCB_CONNECT: s->cb_connect = func; break;
case SCB_DISCONNECT: s->cb_disconn = func; break;
case SCB_ACCEPT: s->cb_accept = func; break;
case SCB_READ: s->cb_read = func; break;
case SCB_READLINE: s->cb_readline = func; break;
case SCB_TRIGGER: s->cb_trigger = func; break;
default:
log("sockets: sock_setcb(): invalid callback ID %d", which);
break;
}
RETURN;
}
/*************************************************************************/
/* Return whether the given socket is currently connected. */
int sock_isconn(const Socket *s)
{
ENTER_WITH("%d", "%p", s);
if (!s) {
log("sockets: sock_isconn() with NULL socket!");
errno = EINVAL;
RETURN_WITH(0);
}
RETURN_WITH(s->flags & SF_CONNECTED ? 1 : 0);
}
/*************************************************************************/
/* Retrieve address of remote end of socket. Functions the same way as
* getpeername() (initialize *lenptr to sizeof(sa), address returned in sa,
* non-truncated length of address returned in *lenptr). Returns -1 with
* errno == EINVAL if a NULL pointer is passed or the given socket is not
* connected.
*/
int sock_remote(const Socket *s, struct sockaddr *sa, int *lenptr)
{
ENTER_WITH("%d", "%p,%p,%p", s, sa, lenptr);
if (!s || !sa || !lenptr || !(s->flags & SF_CONNECTED)) {
if (!s || !sa || !lenptr) {
log("sockets: sock_remote() with NULL %s!",
!s ? "socket" : !sa ? "sockaddr" : "lenptr");
}
errno = EINVAL;
RETURN_WITH(-1);
}
if (sizeof(s->remote) <= *lenptr)
memcpy(sa, &s->remote, sizeof(s->remote));
else
memcpy(sa, &s->remote, *lenptr);
*lenptr = sizeof(s->remote);
RETURN_WITH(0);
}
/*************************************************************************/
/* Set whether socket writes should block (blocking != 0) or not
* (blocking == 0).
*/
void sock_set_blocking(Socket *s, int blocking)
{
ENTER("%p,%d", s, blocking);
if (!s) {
log("sockets: sock_set_blocking() with NULL socket!");
errno = EINVAL;
RETURN;
}
if (blocking)
s->flags |= SF_BLOCKING;
else
s->flags &= ~SF_BLOCKING;
RETURN;
}
/*************************************************************************/
/* Return whether socket writes are blocking (return value > 0) or not
* (return value == 0). Returns -1 if socket is invalid.
*/
int sock_get_blocking(const Socket *s)
{
ENTER_WITH("%d", "%p", s);
if (!s) {
log("sockets: sock_get_blocking() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
RETURN_WITH(s->flags & SF_BLOCKING);
}
/*************************************************************************/
/* Set (or clear, if seconds==0) the write timeout for a socket. */
void sock_set_wto(Socket *s, int seconds)
{
ENTER("%p,%d", s, seconds);
if (!s || seconds < 0) {
log("sockets: sock_set_wto() with %s!",
!s ? "NULL socket" : "negative timeout");
errno = EINVAL;
RETURN;
}
s->write_timeout = seconds;
RETURN;
}
/*************************************************************************/
/* Mute a socket. When a socket is muted, no arriving data will be
* acknowledged (except to the extent that the operating system
* automatically acknowledges and buffers the data), and the read and
* accept callbacks will not be called. However, a socket in the
* process of conenction will still call the connect or disconnect
* callbacks when it completes or fails.
*/
void sock_mute(Socket *s)
{
ENTER("%p", s);
if (!s) {
log("sockets: sock_mute() with NULL socket!");
RETURN;
}
if (!(s->flags & SF_MUTE)) {
if (s->fd >= 0)
FD_CLR(s->fd, &sock_fds);
s->flags |= SF_MUTE;
}
RETURN;
}
/*************************************************************************/
/* Unmute a socket. If any data is waiting, it will be acknowledged and
* the appropriate callback (read or accept) called during the next call to
* check_sockets().
*/
void sock_unmute(Socket *s)
{
ENTER("%p", s);
if (!s) {
log("sockets: sock_unmute() with NULL socket!");
RETURN;
}
if (s->flags & SF_MUTE) {
if (s->fd >= 0)
FD_SET(s->fd, &sock_fds);
s->flags &= ~SF_MUTE;
s->flags |= SF_UNMUTED;
}
RETURN;
}
/*************************************************************************/
/* Return amount of data in read buffer. Assumes socket is valid. */
inline uint32 read_buffer_len(const Socket *s)
{
if (s->rend >= s->rptr)
return s->rend - s->rptr;
else
return (s->rend + read_buffer_size(s)) - s->rptr;
}
/*************************************************************************/
/* Return amount of data in write buffer. Assumes socket is valid. */
inline uint32 write_buffer_len(const Socket *s)
{
if (s->wend >= s->wptr)
return s->wend - s->wptr;
else
return (s->wend + write_buffer_size(s)) - s->wptr;
}
/*************************************************************************/
/* Return total number of bytes received and sent on this socket in
* *read_ret and *writekb_ret respectively. Sent data count does not
* include buffered but unsent data. Returns 0 on success, -1 on error
* (invalid socket).
*/
int sock_rwstat(const Socket *s, uint64 *read_ret, uint64 *written_ret)
{
ENTER_WITH("%u", "%p,%p,%p", s, read_ret, written_ret);
if (!s) {
log("sockets: sock_rwstat() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
if (read_ret)
*read_ret = s->total_read;
if (written_ret)
*written_ret = s->total_written;
RETURN_WITH(0);
}
/*************************************************************************/
/* Return the larger of (1) the ratio of the given socket's total buffer
* size (read and write buffers combined) to bufsize_limit and (2) the
* ratio of the amount of memory used by all sockets' buffers to
* total_bufsize_limit, as a percentage rounded up to the next integer.
* Ratios (1) and (2) are zero if bufsize_limit or total_bufsize_limit,
* respectively, are set to zero (unlimited).
*
* If any of `socksize_ret', `totalsize_ret', `ratio1_ret', and
* `ratio2_ret' are non-NULL, they are set respectively to the given
* socket's total buffer size, the amount of memory used by all sockets'
* buffers, ratio (1) as a percentage, and ratio (2) as a percentage.
*
* If `s' is NULL, ratio (1) is set to zero, and *socksize_ret is not
* modified.
*/
int sock_bufstat(const Socket *s, uint32 *socksize_ret,
uint32 *totalsize_ret, int *ratio1_ret, int *ratio2_ret)
{
int ratio1 = 0, ratio2 = 0;
ENTER_WITH("%d", "%p,%p,%p,%p,%p", s, socksize_ret, totalsize_ret,
ratio1_ret, ratio2_ret);
if (bufsize_limit && s) {
uint32 size = read_buffer_size(s) + write_buffer_size(s);
if (bufsize_limit <= 0x7FFFFFFF/100)
ratio1 = (size*100 + bufsize_limit-1) / bufsize_limit;
else
ratio1 = (size + bufsize_limit/100-1) / (bufsize_limit/100);
}
if (total_bufsize_limit) {
if (bufsize_limit <= 0x7FFFFFFF/100)
ratio2 = (total_bufsize*100 + total_bufsize_limit-1)
/ total_bufsize_limit;
else
ratio2 = (total_bufsize + total_bufsize_limit/100-1)
/ (total_bufsize_limit/100);
}
if (socksize_ret && s)
*socksize_ret = read_buffer_size(s) + write_buffer_size(s);
if (totalsize_ret)
*totalsize_ret = total_bufsize;
if (ratio1_ret)
*ratio1_ret = ratio1;
if (ratio2_ret)
*ratio2_ret = ratio2;
if (ratio1 > ratio2)
RETURN_WITH(ratio1);
else
RETURN_WITH(ratio2);
}
/*************************************************************************/
/*************************************************************************/
/* Check all sockets for activity, and call callbacks as necessary.
* Returns after activity has been detected on at least one socket.
*/
void check_sockets(void)
{
fd_set rfds, wfds;
int i;
int32 res;
struct timeval tv;
time_t now = time(NULL);
Socket *s;
ENTER("");
rfds = sock_fds;
wfds = write_fds;
if (read_timeout < 0) {
tv.tv_sec = -1; // flag: use a NULL tv parameter to select()
tv.tv_usec = 0;
} else {
tv.tv_sec = read_timeout/1000;
tv.tv_usec = (read_timeout%1000) * 1000;
}
for (i = 0; i < max_fd; i++) {
s = sockets[i];
if (s && s->write_timeout && MORE_TO_WRITE(s)) {
int tleft = s->write_timeout - (now - s->last_write_time);
if (tleft < 0)
tleft = 0;
if (tv.tv_sec < 0 || tleft <= tv.tv_sec) {
tv.tv_sec = tleft;
tv.tv_usec = 0;
}
}
}
enable_signals();
do {
struct timeval thistv = tv;
res = select(max_fd, &rfds, &wfds, NULL, tv.tv_sec<0?NULL:&thistv);
} while (res < 0 && errno == EINTR);
disable_signals();
log_debug(3, "sockets: select returned %d", res);
if (res < 0) {
log_perror("sockets: select()");
RETURN;
}
for (i = 0; i < max_fd; i++) {
s = sockets[i];
if (!s)
continue;
if (s->fd != i) {
log("sockets: BUG: sockets[%d]->fd = %d (should be equal),"
" clearing socket from table", i, s->fd);
sockets[i] = NULL;
continue;
}
if (FD_ISSET(i, &wfds)) {
log_debug(3, "sockets: write ready on fd %d", i);
if (!s) {
log("sockets: BUG: got write-ready on fd %d but no socket"
" for it!", i);
continue;
} else if (s->flags & SF_CONNECTING) {
/* Connection established (or failed) */
int val;
socklen_t vallen;
vallen = sizeof(val);
log_debug(2, "sockets: connect on fd %d returned", i);
if (getsockopt(i, SOL_SOCKET, SO_ERROR, &val, &vallen) < 0) {
log_perror("sockets: getsockopt(SO_ERROR) for connect (%d"
" -> %s:%u)", i, inet_ntoa(s->remote.sin_addr),
htons(s->remote.sin_port));
do_disconn(s, DISCONN_CONNFAIL);
continue;
}
if (val != 0) {
errno = val;
log_perror("sockets: connect(%d -> %s:%u)", i,
inet_ntoa(s->remote.sin_addr),
htons(s->remote.sin_port));
do_disconn(s, DISCONN_CONNFAIL);
continue;
} else {
if (!do_callback(s, s->cb_connect, 0))
continue;
}
s->flags &= ~SF_CONNECTING;
s->flags |= SF_CONNECTED;
FD_CLR(i, &write_fds);
if (flush_write_buffer(s) < 0) /* we may have pending data */
continue; /* socket is not valid any more */
if (!(s->flags & SF_MUTE))
FD_SET(i, &sock_fds);
} else if (!(s->flags & SF_CONNECTED)) {
log("sockets: BUG: got write-ready on fd %d but socket not"
" connected!", i);
} else {
if (flush_write_buffer(s) < 0)
continue; /* socket is not valid any more */
}
} /* set in write fds */
while (s->flags & SF_WTRIGGER) {
/* Write trigger reached */
void *userdata = (void *)s->writemap->map;
next_wmap(s);
s->flags &= ~SF_WTRIGGER;
do_callback(s, s->cb_trigger, userdata);
}
if (FD_ISSET(i, &rfds) || (s && (s->flags & SF_UNMUTED))) {
log_debug(3, "sockets: %s on fd %d",
FD_ISSET(i,&rfds) ? "read ready" : "unmute", i);
if (!s) {
log("sockets: BUG: got data on fd %d but no socket for it!",i);
FD_CLR(i, &sock_fds);
continue;
}
if (s->flags & SF_MUTE) {
/* Socket was muted by a previous socket's callback */
log_debug(3, "sockets: socket %d has been muted", i);
continue;
}
s->flags &= ~SF_UNMUTED;
if (FD_ISSET(i, &rfds)) {
if (s->flags & SF_LISTENER) {
/* Connection arrived */
do_accept(s);
continue;
} else if (!(s->flags & SF_CONNECTED)) {
log("sockets: BUG: got data on fd %d but not connected!",
i);
FD_CLR(i, &sock_fds);
continue;
}
/* Normal read */
if (read_buffer_len(s) >= read_buffer_size(s)-1) {
/* Buffer is full, try to expand it */
int newsize = 0;
if (read_buffer_size(s) < SOCK_MIN_BUFSIZE)
newsize = SOCK_MIN_BUFSIZE;
else if (read_buffer_size(s)+SOCK_MIN_BUFSIZE<bufsize_limit)
newsize = read_buffer_size(s) + SOCK_MIN_BUFSIZE;
if (newsize > 0)
resize_rbuf(s, newsize);
}
res = fill_read_buffer(s);
if (res < 0) {
/* Connection was closed (or some other error occurred) */
if (res < 0)
log_perror_debug(1, "sockets: recv(%d)", i);
do_disconn(s, DISCONN_REMOTE);
continue;
} else if (res == 0) {
/* Read buffer is full (NOTE: this causes busy waiting
* until space is made available) */
}
} else {
res = read_buffer_len(s);
}
if (res > 0) {
uint32 left = read_buffer_len(s), newleft;
if (left == 0) {
log("sockets: BUG: 0 bytes avail after successful read!");
continue;
}
/* Call read callback(s) in a loop until no more data is
* left or neither callback takes any data, or the socket is
* disconnected */
newleft = left;
do {
if (!do_callback(s, s->cb_read, (void *)(long)newleft))
goto disconnected;
if (s->flags & SF_MUTE)
break;
newleft = read_buffer_len(s);
if (s->cb_readline) {
char *newline;
if (s->rend > s->rptr) {
newline = memchr(s->rptr, '\n', newleft);
} else {
newline = memchr(s->rptr, '\n', s->rtop - s->rptr);
if (!newline)
newline = memchr(s->rbuf, '\n',
s->rend - s->rbuf);
}
if (newline) {
if (!do_callback(s, s->cb_readline,
(void *)(long)newleft))
goto disconnected;
if (s->flags & SF_MUTE)
break;
newleft = read_buffer_len(s);
}
}
} while (newleft != left && (left = newleft) != 0);
reclaim_buffer_space_one(s);
}
} /* socket ready for reading or unmuted */
if (s->write_timeout
&& MORE_TO_WRITE(s)
&& s->last_write_time + s->write_timeout <= now
) {
if (s->flags & SF_DISCONNECT)
do_disconn(s, DISCONN_LOCAL_RESUME);
else
do_disconn(s, DISCONN_REMOTE);
}
disconnected:
/* at least one statement is required after a label */ ;
} /* for all sockets */
RETURN;
} /* check_sockets() */
/*************************************************************************/
/*************************************************************************/
/* Initiate a connection to the given host and port. If an error occurs,
* returns -1, else returns 0. The connection is not necessarily complete
* even if 0 is returned, and may later fail; use the SCB_CONNECT and
* SCB_DISCONNECT callbacks. If this function fails due to inability to
* resolve a hostname, errno will be set to the negative of h_errno; pass
* the negative of this value to hstrerror() to get an appropriate error
* message.
*
* lhost/lport specify the local side of the connection. If they are not
* given (lhost==NULL, lport==0), then they are left to be set by the OS.
*
* If either host or lhost is not a valid IP address and the gethostbyname()
* function is available, this function may block while the hostname is
* being resolved.
*
* This function may be called from a socket's disconnect callback to
* establish a new connection using the same socket. It may not be called,
* however, if the socket is being freed with sock_free().
*/
int conn(Socket *s, const char *host, int port, const char *lhost, int lport)
{
#if HAVE_GETHOSTBYNAME
struct hostent *hp;
#endif
uint8 *addr;
struct sockaddr_in sa, lsa;
int fd, i;
ENTER_WITH("%d", "%p,[%s],%d,[%s],%d", s, host?host:"(null)", port,
lhost?lhost:"(null)", lport);
if (!s || !host || port <= 0 || port > 65535) {
if (port <= 0 || port > 65535)
log("sockets: conn() with bad port number (%d)!", port);
else
log("sockets: conn() with NULL %s!", !s ? "socket" : "hostname");
errno = EINVAL;
RETURN_WITH(-1);
}
if (s->flags & SF_DELETEME) {
log("sockets: conn() called on a freeing socket (%p)", s);
errno = EPERM;
return -1;
}
memset(&lsa, 0, sizeof(lsa));
lsa.sin_family = AF_INET;
if (lhost) {
if ((addr = pack_ip(lhost)) != 0)
memcpy((char *)&lsa.sin_addr, addr, 4);
#if HAVE_GETHOSTBYNAME
else if ((hp = gethostbyname(lhost)) != NULL)
memcpy((char *)&lsa.sin_addr, hp->h_addr, hp->h_length);
#endif
else
lhost = NULL;
}
if (lport)
lsa.sin_port = htons(lport);
memset(&sa, 0, sizeof(sa));
if ((addr = pack_ip(host)) != 0) {
memcpy((char *)&sa.sin_addr, addr, 4);
sa.sin_family = AF_INET;
}
#if HAVE_GETHOSTBYNAME
else if ((hp = gethostbyname(host)) != NULL) {
memcpy((char *)&sa.sin_addr, hp->h_addr, hp->h_length);
sa.sin_family = hp->h_addrtype;
} else {
errno = -h_errno;
RETURN_WITH(-1);
}
#else
else {
log("sockets: conn(): `%s' is not a valid IP address", host);
errno = EINVAL;
RETURN_WITH(-1);
}
#endif
sa.sin_port = htons((uint16)port);
if ((fd = socket(sa.sin_family, SOCK_STREAM, 0)) < 0)
RETURN_WITH(-1);
if (fcntl(fd, F_SETFL, O_NDELAY) < 0) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if ((lhost || lport) && bind(fd,(struct sockaddr *)&lsa,sizeof(sa)) < 0) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if ((i = connect(fd, (struct sockaddr *)&sa, sizeof(sa))) < 0
&& errno != EINPROGRESS
) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if (max_fd < fd+1) {
int j;
void *new_sockets = realloc(sockets, (fd+1) * sizeof(*sockets));
if (!new_sockets) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
sockets = new_sockets;
for (j = max_fd; j < fd; j++)
sockets[j] = NULL;
max_fd = fd+1;
}
sockets[fd] = s;
s->remote = sa;
s->fd = fd;
s->flags &= ~(SF_CONNECTING | SF_CONNECTED);
if (i == 0) {
s->flags |= SF_CONNECTED;
if (!(s->flags & SF_MUTE))
FD_SET(fd, &sock_fds);
do_callback(s, s->cb_connect, 0);
} else {
s->flags |= SF_CONNECTING;
FD_SET(fd, &write_fds);
}
RETURN_WITH(0);
}
/*************************************************************************/
/* Disconnect a socket. Returns 0 on success, -1 on error (s == NULL or
* listener socket). Calling this routine on an already-disconnected
* socket returns success without doing anything. Note that the socket may
* not be disconnected immediately; callers who intend to reuse the socket
* MUST wait until the disconnect callback is called before doing so.
*/
int disconn(Socket *s)
{
ENTER_WITH("%d", "%p", s);
if (!s) {
log("sockets: disconn() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
} else if (s->flags & SF_LISTENER) {
log("sockets: disconn() with listener socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
RETURN_WITH(do_disconn(s, DISCONN_LOCAL));
}
/*************************************************************************/
/* Open a listener socket on the given host and port; returns 0 on success
* (the socket is set up and listening), -1 on error. If `host' has
* multiple addresses, only the first one is used; if `host' is NULL, all
* addresses are bound to. As with conn(), a negative errno value
* indicates a failure to resolve the hostname `host'. `backlog' is the
* backlog limit for incoming connections, and is passed directly to the
* listen() system call.
*
* Note that if the SCB_ACCEPT callback is not set, any connections to the
* socket will be dropped immediately.
*
* If host is not a valid IP address and the gethostbyname() function is
* available, this function may block while the hostname is being resolved.
*/
int open_listener(Socket *s, const char *host, int port, int backlog)
{
#if HAVE_GETHOSTBYNAME
struct hostent *hp;
#endif
uint8 *addr;
struct sockaddr_in sa;
int fd, i;
ENTER_WITH("%d", "%p,[%s],%d,%d", s, host?host:"(null)", port, backlog);
if (!s || port <= 0 || port > 65535 || backlog < 1) {
if (port <= 0 || port > 65535)
log("sockets: open_listener() with bad port number (%d)!", port);
else if (backlog < 1)
log("sockets: open_listener() with bad backlog (%d)!", backlog);
else
log("sockets: open_listener() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
memset(&sa, 0, sizeof(sa));
if (host) {
if ((addr = pack_ip(host)) != 0) {
memcpy((char *)&sa.sin_addr, addr, 4);
sa.sin_family = AF_INET;
}
#if HAVE_GETHOSTBYNAME
else if ((hp = gethostbyname(host)) != NULL) {
memcpy((char *)&sa.sin_addr, hp->h_addr, hp->h_length);
sa.sin_family = hp->h_addrtype;
} else {
errno = -h_errno;
RETURN_WITH(-1);
}
#else
else {
log("sockets: open_listener(): `%s' is not a valid IP address",
host);
errno = EINVAL;
RETURN_WITH(-1);
}
#endif
} else { /* !host */
sa.sin_family = AF_INET;
sa.sin_addr.s_addr = INADDR_ANY;
}
sa.sin_port = htons((uint16)port);
if ((fd = socket(sa.sin_family, SOCK_STREAM, 0)) < 0)
RETURN_WITH(-1);
i = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i)) < 0) {
log_perror("sockets: open_listener(): setsockopt(%d, SO_REUSEADDR,"
" 1) failed", fd);
}
if (fcntl(fd, F_SETFL, O_NDELAY) < 0) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if (listen(fd, backlog) < 0) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
if (max_fd < fd+1) {
int j;
void *new_sockets = realloc(sockets, (fd+1) * sizeof(*sockets));
if (!new_sockets) {
int errno_save = errno;
close(fd);
errno = errno_save;
RETURN_WITH(-1);
}
sockets = new_sockets;
for (j = max_fd; j < fd; j++)
sockets[j] = NULL;
max_fd = fd+1;
}
sockets[fd] = s;
if (!(s->flags & SF_MUTE))
FD_SET(fd, &sock_fds);
s->fd = fd;
s->flags |= SF_LISTENER;
/* Listener sockets don't need read/write buffers */
free(s->rbuf);
free(s->wbuf);
s->rbuf = s->rptr = s->rend = s->rtop = NULL;
s->wbuf = s->wptr = s->wend = s->wtop = NULL;
RETURN_WITH(0);
}
/*************************************************************************/
/* Close a listener socket. */
int close_listener(Socket *s)
{
ENTER_WITH("%d", "%p", s);
if (s == NULL || !(s->flags & SF_LISTENER)) {
if (s)
log("sockets: close_listener() with non-listener socket (%d)!",
s->fd);
else
log("sockets: close_listener() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
sock_closefd(s);
s->flags &= ~SF_LISTENER;
RETURN_WITH(0);
}
/*************************************************************************/
/* Read raw data from a socket, like read(). Returns number of bytes read,
* or -1 on error. Only reads from the buffer (does not attempt to fetch
* more data from the connection).
*/
int32 sread(Socket *s, char *buf, int32 len)
{
int32 nread = 0;
ENTER_WITH("%d", "%p,%p,%d", s, buf, len);
if (!s || !buf || len <= 0) {
log("sockets: sread() with %s!",
!s ? "NULL socket" : !buf ? "NULL buffer" : "len <= 0");
errno = EINVAL;
RETURN_WITH(-1);
}
if (s->rend < s->rptr) {
/* Buffer data wraps around */
if (s->rptr + len <= s->rtop) {
/* Only need to read from end of buffer */
memcpy(buf, s->rptr, len);
s->rptr += len;
if (s->rptr >= s->rtop)
s->rptr -= read_buffer_size(s);
RETURN_WITH(len);
} else {
/* Need to read from both end and beginning */
nread = s->rtop - s->rptr;
memcpy(buf, s->rptr, nread);
s->rptr = s->rbuf;
len -= nread;
/* Continue below */
}
}
/* Read data from beginning of buffer */
if (s->rptr < s->rend) {
if (len > s->rend - s->rptr)
len = s->rend - s->rptr;
memcpy(buf+nread, s->rptr, len);
s->rptr += len;
nread += len;
}
/* Return number of bytes read */
RETURN_WITH(nread);
}
/*************************************************************************/
/* Write raw data to a socket, like write(). Returns number of bytes
* written, or -1 on error.
*/
int32 swrite(Socket *s, const char *buf, int32 len)
{
ENTER_WITH("%d", "%p,%p,%d", s, buf, len);
if (!s || !buf || len < 0) {
log("sockets: swrite() with %s!",
!s ? "NULL socket" : !buf ? "NULL buffer" : "len < 0");
errno = EINVAL;
RETURN_WITH(-1);
}
RETURN_WITH(buffered_write(s, buf, len));
}
/*************************************************************************/
/* Write data from an mmap()ed area to a socket. The area will be
* automatically unmapped when the write completes.
*/
int32 swritemap(Socket *s, const char *buf, int32 len)
{
#ifndef DISABLE_SWRITEMAP
struct wmapinfo *info;
ENTER_WITH("%d", "%p,%p,%d", s, buf, len);
if (!s || !buf || len < 0) {
log("sockets: swritemap() with %s!",
!s ? "NULL socket" : !buf ? "NULL buffer" : "len < 0");
errno = EINVAL;
RETURN_WITH(-1);
}
if (!len)
RETURN_WITH(0);
info = malloc(sizeof(*info));
if (!info)
RETURN_WITH(-1);
info->next = NULL;
info->wait = write_buffer_len(s);
info->map = buf;
info->maplen = len;
info->pos = 0;
if (s->writemap) {
if (!s->writemap_tail) {
log("sockets: BUG: socket %d: writemap non-NULL but writemap_tail"
" NULL", s->fd);
s->writemap_tail = s->writemap;
while (s->writemap_tail->next)
s->writemap_tail = s->writemap_tail->next;
}
s->writemap_tail->next = info;
} else {
if (s->writemap_tail) {
log("sockets: BUG: socket %d: writemap NULL but writemap_tail"
" non-NULL", s->fd);
}
s->writemap = info;
}
s->writemap_tail = info;
flush_write_buffer(s); /* to ensure FD is set in write_fds if needed */
RETURN_WITH(len);
#else /* DISABLE_SWRITEMAP */
errno = ENOSYS;
RETURN_WITH(-1);
#endif
}
/*************************************************************************/
/* Add a write trigger to the socket. The `data' parameter will be passed
* to the callback when the trigger is reached. Returns 0 on success, -1
* on failure.
*/
int swrite_trigger(Socket *s, void *data)
{
struct wmapinfo *info;
ENTER_WITH("%d", "%p,%p", s, data);
if (!s) {
log("sockets: swrite_trigger() with NULL socket!");
errno = EINVAL;
RETURN_WITH(-1);
}
info = malloc(sizeof(*info));
if (!info)
RETURN_WITH(-1);
info->next = NULL;
info->wait = write_buffer_len(s);
info->map = (const char *)data;
info->maplen = 0;
info->pos = 0;
if (s->writemap) {
if (!s->writemap_tail) {
log("sockets: BUG: socket %d: writemap non-NULL but writemap_tail"
" NULL", s->fd);
s->writemap_tail = s->writemap;
while (s->writemap_tail->next)
s->writemap_tail = s->writemap_tail->next;
}
s->writemap_tail->next = info;
} else {
if (s->writemap_tail) {
log("sockets: BUG: socket %d: writemap NULL but writemap_tail"
" non-NULL", s->fd);
}
s->writemap = info;
}
s->writemap_tail = info;
flush_write_buffer(s); /* to ensure FD is set in write_fds if needed */
RETURN_WITH(0);
}
/*************************************************************************/
/*************************************************************************/
/* Read a character from a socket, like fgetc(). Returns EOF if no data
* is available in the socket buffer. Assumes the socket is valid.
*/
int sgetc(Socket *s)
{
int c;
ENTER_WITH("%d", "%p", s);
/* No paranoia check here, to save time */
if (s->rptr == s->rend)
RETURN_WITH(EOF);
c = *s->rptr++;
if (s->rptr >= s->rtop)
s->rptr -= read_buffer_size(s);
RETURN_WITH(c);
}
/*************************************************************************/
/* Read a line from a socket, like fgets(). If not enough buffered data
* is available to fill a complete line, or another error occurs, returns
* NULL.
*/
char *sgets(char *buf, int32 len, Socket *s)
{
char *ptr = s->rptr, *eol;
int32 to_top = s->rtop - ptr; /* used for efficiency */
ENTER_WITH("%p", "%p,%d,%p", buf, len, s);
if (!s || !buf || len <= 0) {
log("sockets: sgets[2]() with %s!",
!s ? "NULL socket" : !buf ? "NULL buffer" : "len <= 0");
RETURN_WITH(NULL);
}
/* Find end of line */
if (s->rend > s->rptr) {
eol = memchr(s->rptr, '\n', s->rend - s->rptr);
} else {
eol = memchr(s->rptr, '\n', to_top);
if (!eol)
eol = memchr(s->rbuf, '\n', s->rend - s->rbuf);
}
if (!eol)
RETURN_WITH(NULL);
eol++; /* Point 1 byte after \n */
/* Set rptr now; old value is in ptr variable */
s->rptr = eol;
if (s->rptr >= s->rtop) /* >rtop is impossible, but just in case */
s->rptr = s->rbuf;
/* Note: The greatest possible value for eol is s->rend, so as long as
* we ensure that rend doesn't wrap around and reach rptr (i.e. always
* leave at least 1 byte in the buffer unused), we can never have
* eol == ptr here. */
/* Trim eol to <len bytes */
if (eol > ptr) {
if (eol-ptr >= len)
eol = ptr + len-1;
} else {
if (to_top >= len-1) /* we don't mind eol == rtop */
eol = ptr + len-1;
else if (to_top + (eol - s->rbuf) >= len)
eol = s->rbuf + (len-1 - to_top);
}
/* Actually copy to buffer and return */
if (eol > ptr) {
memcpy(buf, ptr, eol-ptr);
buf[eol-ptr] = 0;
} else {
memcpy(buf, ptr, to_top);
memcpy(buf+to_top, s->rbuf, eol - s->rbuf);
buf[to_top + (eol - s->rbuf)] = 0;
}
RETURN_WITH(buf);
}
/*************************************************************************/
/* Reads a line of text from a socket, and strips newline and carriage
* return characters from the end of the line.
*/
char *sgets2(char *buf, int32 len, Socket *s)
{
char *str;
ENTER_WITH("%p", "%p,%d,%p", buf, len, s);
str = sgets(buf, len, s);
if (!str)
RETURN_WITH(str);
str = buf + strlen(buf)-1;
if (*str == '\n')
*str-- = 0;
if (*str == '\r')
*str = 0;
RETURN_WITH(buf);
}
/*************************************************************************/
/* Write a string to a socket, like fputs(). Returns the number of bytes
* written.
*/
int sputs(const char *str, Socket *s)
{
ENTER_WITH("%d", "[%s],%p", str?str:"(null)", s);
if (!str || !s) {
log("sockets: sputs() with %s!",
!s ? "NULL socket" : "NULL string");
errno = EINVAL;
RETURN_WITH(-1);
}
RETURN_WITH(buffered_write(s, str, strlen(str)));
}
/*************************************************************************/
/* Write to a socket a la [v]printf(). Returns the number of bytes written;
* in no case will more than 65535 bytes be written (if the output would be
* be longer than this, it will be truncated).
*/
int sockprintf(Socket *s, const char *fmt, ...)
{
va_list args;
int ret;
ENTER_WITH("%d", "%p,[%s],...", s, fmt?fmt:"(null)");
va_start(args, fmt);
ret = vsockprintf(s, fmt, args);
va_end(args);
RETURN_WITH(ret);
}
int vsockprintf(Socket *s, const char *fmt, va_list args)
{
char buf[65536];
ENTER_WITH("%d", "%p,[%s],%p", s, fmt?fmt:"(null)", args);
if (!s || !fmt) {
log("sockets: [v]sockprintf() with %s!",
!s ? "NULL socket" : "NULL format string");
errno = EINVAL;
RETURN_WITH(-1);
}
RETURN_WITH(buffered_write(s, buf, vsnprintf(buf,sizeof(buf),fmt,args)));
}
/*************************************************************************/
/************************** Internal routines ****************************/
/*************************************************************************/
/* Call a callback on the given socket. Handles setting and clearing
* SF_CALLBACK, and checking for remote disconnects after the callback
* completes. Returns 0 if the socket has been disconnected, 1 otherwise.
* If 0 is returned, the socket should be considered no longer valid; if it
* was an automatically-created socket, the socket itself will have been
* freed.
*
* `s' or `cb' may be NULL, in which case this routine does nothing and
* returns 1.
*/
static int do_callback(Socket *s, SocketCallback cb, void *param)
{
ENTER_WITH("%d", "%p,%p,%p", s, cb, param);
if (s && cb) {
/* Check whether the SF_CALLBACK flag was set; if it is, then this
* is a nested callback, so don't clear the flag or disconnect the
* socket afterwards. */
int was_set = s->flags & SF_CALLBACK;
if (!was_set)
s->flags |= SF_CALLBACK;
log_debug(3, "sockets: callback(%d,%p,%p)", s->fd, cb, param);
cb(s, param);
log_debug(3, "sockets: ...cbret(%d,%p,%p)", s->fd, cb, param);
if (!was_set) {
s->flags &= ~SF_CALLBACK;
if (s->flags & SF_BROKEN) {
log_debug(3, "sockets: ...broken");
do_disconn(s, DISCONN_REMOTE_RESUME);
RETURN_WITH(0);
}
if (s->flags & SF_DELETEME) {
log_debug(3, "sockets: ...deleteme");
sock_free(s);
RETURN_WITH(0);
}
if ((s->flags & SF_DISCONNECT) || s->fd < 0) {
log_debug(3, "sockets: ...disconnect");
RETURN_WITH(0);
}
log_debug(3, "sockets: ...normalret");
} else { /* SF_CALLBACK was already set */
log_debug(3, "sockets: ...nestedret");
}
}
RETURN_WITH(1);
}
/*************************************************************************/
/* Accept a connection on the given socket. Called from check_sockets(). */
static void do_accept(Socket *s)
{
int i;
struct sockaddr_in sin;
socklen_t sin_len = sizeof(sin);
int newfd;
ENTER("%p", s);
newfd = accept(s->fd, (struct sockaddr *)&sin, &sin_len);
if (newfd < 0) {
if (errno != ECONNRESET)
log_perror("sockets: accept(%d)", s->fd);
} else if (!s->cb_accept) {
/* No accept callback, so just throw the connection away */
close(newfd);
} else if (fcntl(newfd, F_SETFL, O_NDELAY) < 0) {
log_perror("sockets: fcntl(NDELAY) on accept(%d)", s->fd);
close(newfd);
} else {
Socket *news = sock_new();
if (!news) {
log("sockets: accept(%d): Unable to create socket structure"
" (out of buffer space?)", s->fd);
} else {
news->fd = newfd;
news->flags |= SF_SELFCREATED | SF_CONNECTED;
memcpy(&news->remote, &sin, sin_len);
for (i = newfd; i < max_fd; i++);
if (max_fd < newfd+1) {
void *new_sockets =
realloc(sockets, (newfd+1) * sizeof(*sockets));
if (!new_sockets) {
sock_free(news);
close(newfd);
RETURN;
}
sockets = new_sockets;
for (i = max_fd; i < newfd; i++)
sockets[i] = NULL;
max_fd = newfd+1;
}
sockets[newfd] = news;
if (!(news->flags & SF_MUTE))
FD_SET(newfd, &sock_fds);
do_callback(s, s->cb_accept, news);
}
}
RETURN;
}
/*************************************************************************/
/* Fill up the read buffer of a socket with any data that may have arrived.
* Returns the number of bytes read (nonzero), or -1 on error; errno is set
* by recv() calls but is otherwise preserved.
*/
static int fill_read_buffer(Socket *s)
{
int nread = 0;
int errno_save = errno;
ENTER_WITH("%d", "%p", s);
if (s->fd < 0) {
errno = EBADF;
RETURN_WITH(-1);
}
for (;;) {
int maxread, res;
if (read_buffer_len(s) >= read_buffer_size(s)-1) {
/* Read buffer is full; try to expand the buffer. */
int over;
int32 more = resize_how_much(s, read_buffer_size(s), &over);
if (more) {
if (!resize_rbuf(s, read_buffer_size(s) + more)) {
log("sockets: attempt to expand socket %d read buffer"
" failed (out of memory?)", s->fd);
errno_save = EAGAIN;
if (nread == 0)
nread = -1;
break;
}
} else {
#ifdef WARN_ON_BUFSIZE
if (!(s->flags & SF_WARNED)) {
log("sockets: socket %d exceeded %s buffer size limit"
" (%d)", s->fd, over ? "per-connection" : "total",
over ? bufsize_limit : total_bufsize_limit);
s->flags |= SF_WARNED;
}
#endif
errno_save = EAGAIN;
if (nread == 0)
nread = -1;
break;
}
}
if (s->rend < s->rptr) /* wrapped around? */
maxread = (s->rptr-1) - s->rend;
else if (s->rptr == s->rbuf)
maxread = s->rtop - s->rend - 1;
else
maxread = s->rtop - s->rend;
do {
errno = 0;
res = recv(s->fd, s->rend, maxread, 0);
if (res <= 0 && errno == 0)
errno = ECONNRESET; /* make a guess */
} while (res <= 0 && errno == EINTR);
errno_save = errno;
log_debug(3, "sockets: fill_read_buffer wanted %d, got %d",
maxread, nread);
if (res <= 0) {
if (nread == 0)
nread = -1;
break;
}
nread += res;
s->total_read += res;
s->rend += res;
if (s->rend == s->rtop)
s->rend = s->rbuf;
}
if (nread == 0) {
nread = -1;
errno = ENOBUFS;
} else {
errno = errno_save;
}
RETURN_WITH(nread);
}
/*************************************************************************/
/* Try and write up to one chunk of data from the buffer to the socket.
* Return -1 on error, -2 if a socket waiting for disconnection was closed,
* or else how many bytes were written. (Note that a return value of zero
* should not be considered an error.)
*/
static int flush_write_buffer(Socket *s)
{
int32 maxwrite, nwritten;
ENTER_WITH("%d", "%p", s);
if (s->fd < 0) {
errno = EBADF;
RETURN_WITH(-1);
}
if (!sock_isconn(s)) /* not yet connected */
RETURN_WITH(0);
if (s->flags & SF_WTRIGGER) {
/* Write trigger is still pending on this socket, don't do anything */
nwritten = 0;
goto check_result;
}
/* "while" instead of "if" to handle the case of:
* s->writemap->wait == 0
* s->writemap->pos == s->writemap->maplen (should be impossible here)
* s->writemap->next->wait == 0
*/
while (s->writemap && s->writemap->wait <= 0) {
/* Write data from the map instead of the buffer */
if (!s->writemap->maplen) {
/* It's a trigger, stop here. We don't skip to the next wmap
* yet in case we're called again before the trigger callback
* is called. */
s->flags |= SF_WTRIGGER;
nwritten = 0; /* return value */
goto check_result;
}
maxwrite = s->writemap->maplen - s->writemap->pos;
if (maxwrite > 0) {
nwritten = send(s->fd, s->writemap->map + s->writemap->pos,
maxwrite, 0);
log_debug(3, "sockets: flush_write_buffer/map wanted %d, got %d",
maxwrite, nwritten);
if (nwritten > 0) {
s->writemap->pos += nwritten;
if (s->writemap->pos >= s->writemap->maplen)
next_wmap(s);
}
goto check_result;
} else {
next_wmap(s);
}
}
nwritten = 0;
if (s->wend != s->wptr) {
if (s->wptr > s->wend) /* wrapped around? */
maxwrite = s->wtop - s->wptr;
else
maxwrite = s->wend - s->wptr;
if (s->writemap && maxwrite > s->writemap->wait) {
maxwrite = s->writemap->wait;
if (maxwrite <= 0) {
/* paranoia: this is impossible from the while() above */
log("sockets: BUG: flush_write_buffer(%d): writemap wait 0"
" after while", s->fd);
do_disconn(s, DISCONN_REMOTE);
RETURN_WITH(-1);
}
}
nwritten = send(s->fd, s->wptr, maxwrite, 0);
log_debug(3, "sockets: flush_write_buffer wanted %d, got %d",
maxwrite, nwritten);
if (nwritten > 0) {
struct wmapinfo *info;
for (info = s->writemap; info; info = info->next) {
info->wait -= nwritten;
}
s->wptr += nwritten;
if (s->wptr >= s->wtop)
s->wptr = s->wbuf;
}
check_result:
if (nwritten < 0 && errno != EAGAIN && errno != EINTR) {
int errno_save = errno;
if (errno != ECONNRESET && errno != EPIPE)
log_perror("sockets: flush_write_buffer(%d)", s->fd);
do_disconn(s, DISCONN_REMOTE);
errno = errno_save;
RETURN_WITH(-1);
}
if (nwritten > 0) {
s->last_write_time = time(NULL);
s->flags &= ~SF_WARNED;
s->total_written += nwritten;
} else {
nwritten = 0; /* return value */
}
}
if ((s->flags & SF_CALLBACK) || MORE_TO_WRITE(s)) {
FD_SET(s->fd, &write_fds);
} else {
FD_CLR(s->fd, &write_fds);
if (s->flags & SF_DISCONNECT) {
s->flags &= ~SF_DISCONNECT;
do_disconn(s, DISCONN_LOCAL_RESUME);
RETURN_WITH(-2);
} else {
reclaim_buffer_space_one(s);
}
}
RETURN_WITH(nwritten);
}
/*************************************************************************/
/* Return the amount by which a socket's read or write buffer should be
* expanded. Return zero if the per-connection or total network buffer
* size limits have been reached and the buffer cannot be expanded; in
* this case, set *errp to 1 if the per-connection buffer size limit was
* exceeded, 0 if the total buffer size limit was exceeded.
*/
static uint32 resize_how_much(const Socket *s, uint32 current_size, int *errp)
{
uint32 socktotal = read_buffer_size(s) + write_buffer_size(s);
int32 more;
int over = 0, over_total = 0;
/* Check current size against limits */
if (bufsize_limit && socktotal >= bufsize_limit)
over = 1;
if (total_bufsize_limit && total_bufsize >= total_bufsize_limit)
over_total = 1;
if (over || over_total) {
if (over)
*errp = 1;
else
*errp = 0;
return 0;
}
/* Expand by 10%, rounded up to a multiple of SOCK_MIN_BUFSIZE */
more = current_size / 10;
more = (more+SOCK_MIN_BUFSIZE-1) / SOCK_MIN_BUFSIZE * SOCK_MIN_BUFSIZE;
/* Make sure new size doesn't exceed limits */
if (bufsize_limit && socktotal + more >= bufsize_limit)
more = bufsize_limit - socktotal;
if (total_bufsize_limit && total_bufsize + more >= total_bufsize_limit)
more = total_bufsize_limit - total_bufsize;
if (more < 0) {
more = 0;
/* This shouldn't be possible; assume it's the total buffer size */
*errp = 0;
}
/* Return it */
return more;
}
/* Resize a socket's read or write buffer. */
static int resize_rbuf(Socket *s, uint32 size)
{
ENTER("%p,%u", s, size);
if (size <= read_buffer_len(s)) {
log("sockets: BUG: resize_rbuf(%d): size (%d) <= rlen (%d)"
" (cursize %ld)", s->fd, size, read_buffer_len(s),
(long)(s->rtop - s->rbuf));
RETURN_WITH(0);
}
RETURN_WITH(resize_buf(&s->rbuf, &s->rptr, &s->rend, &s->rtop, size));
}
static int resize_wbuf(Socket *s, uint32 size)
{
ENTER("%p,%u", s, size);
if (size <= write_buffer_len(s)) {
log("sockets: BUG: resize_wbuf(%d): size (%d) <= wlen (%d)"
" (cursize %ld)", s->fd, size, write_buffer_len(s),
(long)(s->wtop - s->wbuf));
RETURN_WITH(0);
}
RETURN_WITH(resize_buf(&s->wbuf, &s->wptr, &s->wend, &s->wtop, size));
}
/* Routine that does the actual resizing. Assumes that newsize >= current
* size. Returns nonzero on success, zero on failure (out of memory). */
static int resize_buf(char **p_buf, char **p_ptr, char **p_end, char **p_top,
uint32 newsize)
{
uint32 size = *p_top - *p_buf;
char *newbuf;
uint32 len = 0;
ENTER_WITH("%d", "%p,%p,%p,%p,%u", p_buf, p_ptr, p_end, p_top, newsize);
if (newsize <= size)
RETURN_WITH(1);
newbuf = malloc(newsize);
if (!newbuf)
RETURN_WITH(0);
total_bufsize -= size;
total_bufsize += newsize;
/* Copy old data to new buffer, if any */
if (*p_end < *p_ptr) {
len = *p_top - *p_ptr;
memcpy(newbuf, *p_ptr, len);
*p_ptr = *p_buf;
}
if (*p_end > *p_ptr) {
memcpy(newbuf+len, *p_ptr, *p_end - *p_ptr);
len += *p_end - *p_ptr;
}
free(*p_buf);
*p_buf = newbuf;
*p_ptr = newbuf;
*p_end = newbuf + len;
*p_top = newbuf + newsize;
RETURN_WITH(1);
}
/*************************************************************************/
/* Try to reclaim unused buffer space. Return 1 if some buffer space was
* freed, 0 if not.
*/
static int reclaim_buffer_space_one(Socket *s)
{
uint32 rlen = read_buffer_len(s), wlen = write_buffer_len(s);
int retval = 0;
ENTER_WITH("%d", "%p", s);
if (read_buffer_size(s) > SOCK_MIN_BUFSIZE
&& rlen < read_buffer_size(s) - SOCK_MIN_BUFSIZE
) {
if (rlen < SOCK_MIN_BUFSIZE) {
rlen = SOCK_MIN_BUFSIZE;
} else {
/* Round up to the next multiple of SOCK_MIN_BUFSIZE, leaving
* at least one byte available */
rlen += SOCK_MIN_BUFSIZE;
rlen /= SOCK_MIN_BUFSIZE;
rlen *= SOCK_MIN_BUFSIZE;
}
resize_rbuf(s, rlen);
retval = 1;
}
if (write_buffer_size(s) > SOCK_MIN_BUFSIZE
&& wlen < write_buffer_size(s) - SOCK_MIN_BUFSIZE
) {
if (wlen < SOCK_MIN_BUFSIZE) {
wlen = SOCK_MIN_BUFSIZE;
} else {
wlen += SOCK_MIN_BUFSIZE;
wlen /= SOCK_MIN_BUFSIZE;
wlen *= SOCK_MIN_BUFSIZE;
}
resize_wbuf(s, wlen);
retval = 1;
}
RETURN_WITH(retval);
}
static int reclaim_buffer_space(void)
{
Socket *s;
int retval = 0;
ENTER_WITH("%d", "");
LIST_FOREACH (s, allsockets) {
retval |= reclaim_buffer_space_one(s);
}
RETURN_WITH(retval);
}
/*************************************************************************/
/* Free the first map on the socket's writemap list. */
static void next_wmap(Socket *s)
{
struct wmapinfo *next;
ENTER("%p", s);
if (!s || !s->writemap) {
log("sockets: BUG: next_wmap() with NULL %s!",
s ? "writemap" : "socket");
RETURN;
}
if (s->writemap->map) {
#ifdef DISABLE_SWRITEMAP
log("sockets: BUG: DISABLE_SWRITEMAP but non-NULL map %p for socket"
" %p", s->writemap->map, s);
#else
munmap((void *)s->writemap->map, s->writemap->maplen);
#endif
}
next = s->writemap->next;
free(s->writemap);
if (next) {
s->writemap = next;
} else {
s->writemap = s->writemap_tail = NULL;
}
RETURN;
}
/*************************************************************************/
/* Write data to a socket with buffering. */
static int buffered_write(Socket *s, const char *buf, int len)
{
int nwritten, left = len;
int errno_save = errno;
ENTER_WITH("%d", "%p,%p,%d", s, buf, len);
if (s->fd < 0) {
errno = EBADF;
RETURN_WITH(-1);
}
/* Reset the write timeout if the buffer is currently empty and we're
* not busy writing a mapped buffer. */
if (!MORE_TO_WRITE(s))
s->last_write_time = time(NULL);
while (left > 0) {
/* Fill up to the current buffer size. */
if (write_buffer_len(s) < write_buffer_size(s)-1) {
int maxwrite;
/* If buffer is empty, reset pointers to beginning for efficiency*/
if (write_buffer_len(s) == 0)
s->wptr = s->wend = s->wbuf;
if (s->wptr == s->wbuf) {
/* Buffer not wrapped */
maxwrite = s->wtop - s->wend - 1;
} else {
/* Buffer is wrapped. If this write would reach to or past
* the end of the buffer, write it first and reset the end
* pointer to the beginning of the buffer. */
if (s->wend+left >= s->wtop && s->wptr <= s->wend) {
nwritten = s->wtop - s->wend;
memcpy(s->wend, buf, nwritten);
buf += nwritten;
left -= nwritten;
s->wend = s->wbuf;
}
/* Now we can copy a single chunk to wend. */
if (s->wptr > s->wend)
maxwrite = s->wptr - s->wend - 1;
else
maxwrite = left; /* guaranteed to fit from above code */
}
if (left > maxwrite)
nwritten = maxwrite;
else
nwritten = left;
if (nwritten) {
memcpy(s->wend, buf, nwritten);
buf += nwritten;
left -= nwritten;
s->wend += nwritten;
}
}
/* Now write to the socket as much as we can. */
if (flush_write_buffer(s) < 0)
RETURN_WITH(len - left); /* socket is not valid any more */
errno_save = errno;
if (write_buffer_len(s) >= write_buffer_size(s)-1) {
/* Write failed on full buffer; try to expand the buffer. */
int over;
uint32 more = resize_how_much(s, write_buffer_size(s), &over);
if (more) {
if (!resize_wbuf(s, write_buffer_size(s) + more)) {
/* It would be proper to block here, but if we ran out
* of memory the program's probably about to abort
* anyway, so just error out */
log("sockets: attempt to expand socket %d read buffer"
" failed (out of memory?)", s->fd);
errno_save = EAGAIN;
break;
}
} else {
if ((s->flags & SF_BLOCKING) && !(s->flags & SF_WTRIGGER)) {
fd_set fds;
FD_ZERO(&fds);
FD_SET(s->fd, &fds);
if (select(s->fd+1, NULL, &fds, NULL, NULL) < 0) {
log("sockets: waiting on blocking socket %d: %s",
s->fd, strerror(errno));
break;
}
continue; /* don't expand the buffer, since it's at max */
} else {
#ifdef WARN_ON_BUFSIZE
if (!(s->flags & SF_WARNED)) {
log("sockets: socket %d exceeded %s buffer size"
" limit (%d)", s->fd,
over ? "per-connection" : "total",
over ? bufsize_limit : total_bufsize_limit);
s->flags |= SF_WARNED;
}
#endif
errno_save = EAGAIN;
break;
}
}
}
} /* while (left > 0) */
errno = errno_save;
RETURN_WITH(len - left);
}
/*************************************************************************/
/* Internal version of disconn(), used to pass a specific code to the
* disconnect callback. If code == DISCONN_LOCAL, attempt to first write
* out any data left in the write buffer, and delay disconnection if we
* can't.
*/
static int do_disconn(Socket *s, void *code)
{
int errno_save = errno; /* for passing to the callback */
ENTER_WITH("%d", "%p,%p", s, code);
if (s == NULL || (s->flags & SF_LISTENER)) {
if (s)
log("sockets: BUG: do_disconn(%d) with listener socket (%d)!",
(int)(long)code, s->fd);
else
log("sockets: BUG: do_disconn(%d) with NULL socket!",
(int)(long)code);
errno = EINVAL;
RETURN_WITH(-1);
}
if ((s->flags & SF_DISCONNECTING) && !((int)code & DISCONN_RESUME_FLAG))
RETURN_WITH(0);
if ((s->flags & SF_DISCONN_REQ) && code == DISCONN_LOCAL)
RETURN_WITH(0);
if (!(s->flags & (SF_CONNECTING | SF_CONNECTED)))
RETURN_WITH(0);
s->flags |= SF_DISCONN_REQ;
FD_CLR(s->fd, &sock_fds);
if (code == DISCONN_LOCAL && MORE_TO_WRITE(s)) {
/* Write out any buffered data */
if (flush_write_buffer(s) >= 0 && MORE_TO_WRITE(s)) {
/* Some data is still buffered; request disconnect after it
* goes out */
s->flags |= SF_DISCONNECT;
/* It's not technically disconnected yet, but it will (should)
* succeed eventually */
RETURN_WITH(0);
}
}
s->flags |= SF_DISCONNECTING;
if (code == DISCONN_REMOTE && (s->flags & SF_CALLBACK)) {
/* Socket was closed while a callback was doing something; wait
* until the callback finishes to actually close the socket */
s->flags |= SF_BROKEN;
RETURN_WITH(0);
}
shutdown(s->fd, 2);
sock_closefd(s);
while (s->writemap)
next_wmap(s);
s->writemap_tail = NULL;
if (s->cb_disconn) {
/* The disconnect callback doesn't need to check for disconnection,
* so we just call it directly */
errno = errno_save;
s->cb_disconn(s, (void *)((int)code & ~DISCONN_RESUME_FLAG));
}
s->flags &= ~SF_DISCONNECTING;
if (s->fd >= 0) {
/* The socket was reconnected */
return 0;
}
s->flags &= ~(SF_CONNECTING | SF_CONNECTED);
if (s->flags & (SF_SELFCREATED | SF_DELETEME)) {
if (s->flags & SF_CALLBACK)
s->flags |= SF_DELETEME;
else
sock_free(s);
} else {
reclaim_buffer_space_one(s);
}
RETURN_WITH(0);
}
/*************************************************************************/
/* Close a socket's file descriptor, and clear it from all associated
* structures (s->fd, sockets[], sock_fds, write_fds).
*/
static void sock_closefd(Socket *s)
{
ENTER("%p", s);
/* FIXME: apparently it's possible to come here twice for the same
* connection; under what circumstances can that happen? */
if (s->fd >= 0) {
close(s->fd);
FD_CLR(s->fd, &sock_fds);
FD_CLR(s->fd, &write_fds);
sockets[s->fd] = NULL;
s->fd = -1;
}
RETURN;
}
/*************************************************************************/
/*
* Local variables:
* c-file-style: "stroustrup"
* c-file-offsets: ((case-label . *) (statement-case-intro . *))
* indent-tabs-mode: nil
* End:
*
* vim: expandtab shiftwidth=4:
*/
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