libnmdb/sctp.c

   1
   2 #if ENABLE_SCTP
   3
   4 #include <sys/types.h>          /* socket defines */
   5 #include <sys/socket.h>         /* socket functions */
   6 #include <stdlib.h>             /* malloc() */
   7 #include <stdint.h>             /* uint32_t and friends */
   8 #include <arpa/inet.h>          /* htonls() and friends */
   9 #include <string.h>             /* memcpy() */
  10 #include <unistd.h>             /* close() */
  11
  12 #include <netinet/sctp.h>       /* SCTP stuff */
  13 #include <netdb.h>              /* gethostbyname() */
  14
  15 #include "nmdb.h"
  16 #include "net-const.h"
  17 #include "internal.h"
  18 #include "sctp.h"
  19
  20
  21 /* Used internally to really add the server once we have an IP address. */
  22 static int add_sctp_server_addr(nmdb_t *db, in_addr_t *inetaddr, int port)
  23 {
  24         int fd, rv;
  25         struct nmdb_srv *newsrv, *newarray;
  26
  27         fd = socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP);
  28         if (fd < 0)
  29                 return 0;
  30
  31         /* Disable Nagle algorithm because we often send small
  32          * packets. Huge gain in performance. */
  33         rv = 1;
  34         if (setsockopt(fd, IPPROTO_SCTP, SCTP_NODELAY, &rv, sizeof(rv)) < 0 ) {
  35                 close(fd);
  36                 return 0;
  37         }
  38
  39         newarray = realloc(db->servers,
  40                         sizeof(struct nmdb_srv) * (db->nservers + 1));
  41         if (newarray == NULL) {
  42                 close(fd);
  43                 return 0;
  44         }
  45
  46         db->servers = newarray;
  47         db->nservers++;
  48
  49         if (port < 0)
  50                 port = SCTP_SERVER_PORT;
  51
  52         newsrv = &(db->servers[db->nservers - 1]);
  53
  54         newsrv->fd = fd;
  55         newsrv->info.in.srvsa.sin_family = AF_INET;
  56         newsrv->info.in.srvsa.sin_port = htons(port);
  57         newsrv->info.in.srvsa.sin_addr.s_addr = *inetaddr;
  58         newsrv->info.in.srvlen = sizeof(struct sockaddr_in);
  59
  60         newsrv->type = SCTP_CONN;
  61
  62         /* keep the list sorted by port, so we can do a reliable selection */
  63         qsort(db->servers, db->nservers, sizeof(struct nmdb_srv),
  64                         compare_servers);
  65
  66         return 1;
  67 }
  68
  69 /* Same as nmdb_add_tcp_server() but for SCTP. */
  70 int nmdb_add_sctp_server(nmdb_t *db, const char *addr, int port)
  71 {
  72         int rv;
  73         struct hostent *he;
  74         struct in_addr ia;
  75
  76         /* We try to resolve and then pass it to add_sctp_server_addr(). */
  77         rv = inet_pton(AF_INET, addr, &ia);
  78         if (rv <= 0) {
  79                 he = gethostbyname(addr);
  80                 if (he == NULL)
  81                         return 0;
  82
  83                 ia.s_addr = *( (in_addr_t *) (he->h_addr_list[0]) );
  84         }
  85
  86         return add_sctp_server_addr(db, &(ia.s_addr), port);
  87 }
  88
  89 int sctp_srv_send(struct nmdb_srv *srv, unsigned char *buf, size_t bsize)
  90 {
  91         ssize_t rv;
  92         rv = sendto(srv->fd, buf, bsize, 0,
  93                         (struct sockaddr *) &(srv->info.in.srvsa),
  94                         srv->info.in.srvlen);
  95         if (rv <= 0)
  96                 return 0;
  97         return 1;
  98 }
  99
 100 /* Used internally to get and parse replies from the server. */
 101 uint32_t sctp_get_rep(struct nmdb_srv *srv,
 102                 unsigned char *buf, size_t bsize,
 103                 unsigned char **payload, size_t *psize)
 104 {
 105         ssize_t rv;
 106         uint32_t id, reply;
 107
 108         rv = recv(srv->fd, buf, bsize, 0);
 109         if (rv < 4 + 4) {
 110                 return -1;
 111         }
 112
 113         id = * (uint32_t *) buf;
 114         id = ntohl(id);
 115         reply = * ((uint32_t *) buf + 1);
 116         reply = ntohl(reply);
 117
 118         if (id != ID_CODE) {
 119                 return -1;
 120         }
 121
 122         if (payload != NULL) {
 123                 *payload = buf + 4 + 4;
 124                 *psize = rv - 4 - 4;
 125         }
 126         return reply;
 127 }
 128
 129 #else
 130 /* Stubs to use when SCTP is not enabled. */
 131
 132 #include <stdint.h>
 133 #include "nmdb.h"
 134 #include "sctp.h"
 135
 136 int nmdb_add_sctp_server(nmdb_t *db, const char *addr, int port)
 137 {
 138         return 0;
 139 }
 140
 141 int sctp_srv_send(struct nmdb_srv *srv, unsigned char *buf, size_t bsize)
 142 {
 143         return 0;
 144 }
 145
 146 uint32_t sctp_get_rep(struct nmdb_srv *srv,
 147                 unsigned char *buf, size_t bsize,
 148                 unsigned char **payload, size_t *psize)
 149 {
 150         return -1;
 151 }
 152
 153 #endif /* ENABLE_SCTP */
 154