sock.c

   1 #include <sys/types.h>
   2 #include <sys/socket.h>
   3 #include <fcntl.h>
   4 #include <arpa/inet.h>
   5 #include <linux/if_ether.h>
   6 #include <linux/tcp.h>
   7
   8 #include "sock.h"
   9 #include "die.h"
  10 #include "str.h"
  11 #include "built_in.h"
  12
  13 int af_socket(int af)
  14 {
  15         int sock;
  16
  17         if (unlikely(af != AF_INET && af != AF_INET6))
  18                 panic("Wrong AF socket type!\n");
  19
  20         sock = socket(af, SOCK_DGRAM, 0);
  21         if (unlikely(sock < 0))
  22                 panic("Creation AF socket failed: %s\n", strerror(errno));
  23
  24         return sock;
  25 }
  26
  27 int pf_socket(void)
  28 {
  29         int sock = socket(PF_PACKET, SOCK_RAW, 0);
  30         if (unlikely(sock < 0))
  31                 panic("Creation of PF socket failed: %s\n", strerror(errno));
  32
  33         return sock;
  34 }
  35
  36 /* Avail in kernel >= 3.14
  37  * in commit d346a3fae3 (packet: introduce PACKET_QDISC_BYPASS socket option)
  38  */
  39 void set_sock_qdisc_bypass(int fd, int verbose)
  40 {
  41         int ret, val = 1;
  42
  43         ret = setsockopt(fd, SOL_PACKET, PACKET_QDISC_BYPASS, &val, sizeof(val));
  44         if (ret < 0) {
  45                 if (errno == ENOPROTOOPT) {
  46                         if (verbose)
  47                                 printf("No kernel support for PACKET_QDISC_BYPASS"
  48                                        " (kernel < 3.14?)\n");
  49                 } else
  50                         perror("Cannot set PACKET_QDISC_BYPASS");
  51         } else
  52                 if (verbose) printf("Enabled kernel qdisc bypass\n");
  53 }
  54
  55 void set_sock_prio(int fd, int prio)
  56 {
  57         int ret, val = prio;
  58
  59         ret = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &val, sizeof(val));
  60         if (unlikely(ret))
  61                 panic("Cannot set socket priority: %s\n", strerror(errno));
  62 }
  63
  64 void set_nonblocking(int fd)
  65 {
  66         int ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFD, 0) | O_NONBLOCK);
  67         if (unlikely(ret < 0))
  68                 panic("Cannot fcntl: %s\n", strerror(errno));
  69 }
  70
  71 int set_nonblocking_sloppy(int fd)
  72 {
  73         return fcntl(fd, F_SETFL, fcntl(fd, F_GETFD, 0) | O_NONBLOCK);
  74 }
  75
  76 void set_socket_keepalive(int fd)
  77 {
  78         int ret, one = 1;
  79
  80         ret = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one));
  81         if (unlikely(ret))
  82                 panic("Cannot set TCP keepalive: %s\n", strerror(errno));
  83 }
  84
  85 void set_tcp_nodelay(int fd)
  86 {
  87         int ret, one = 1;
  88
  89         ret = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
  90         if (unlikely(ret))
  91                 panic("Cannot set TCP nodelay: %s\n", strerror(errno));
  92 }
  93
  94 int set_ipv6_only(int fd)
  95 {
  96         int one = 1;
  97         return setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
  98 }
  99
 100 int set_reuseaddr(int fd)
 101 {
 102         int ret, one = 1;
 103
 104         ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
 105         if (unlikely(ret < 0))
 106                 panic("Cannot reuse addr: %s\n", strerror(errno));
 107
 108         return 0;
 109 }
 110
 111 void set_mtu_disc_dont(int fd)
 112 {
 113         int mtu = IP_PMTUDISC_DONT, ret;
 114
 115         ret = setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &mtu, sizeof(mtu));
 116         if (unlikely(ret))
 117                 panic("Cannot set MTU discovery options: %s\n", strerror(errno));
 118 }
 119
 120 enum {
 121         sock_rmem_max = 0,
 122         sock_rmem_def,
 123         sock_wmem_max,
 124         sock_wmem_def,
 125 };
 126
 127 #define SMEM_SUG_MAX    104857600
 128 #define SMEM_SUG_DEF    4194304
 129
 130 static const char *const sock_mem[] = {
 131         [sock_rmem_max] = "/proc/sys/net/core/rmem_max",
 132         [sock_rmem_def] = "/proc/sys/net/core/rmem_default",
 133         [sock_wmem_max] = "/proc/sys/net/core/wmem_max",
 134         [sock_wmem_def] = "/proc/sys/net/core/wmem_default",
 135 };
 136
 137 static int get_system_socket_mem(int which)
 138 {
 139         int fd, val = -1;
 140         ssize_t ret;
 141         const char *file = sock_mem[which];
 142         char buff[64];
 143
 144         fd = open(file, O_RDONLY);
 145         if (fd < 0)
 146                 return val;
 147
 148         ret = read(fd, buff, sizeof(buff));
 149         if (ret > 0)
 150                 val = atoi(buff);
 151
 152         close(fd);
 153         return val;
 154 }
 155
 156 static void set_system_socket_mem(int which, int val)
 157 {
 158         int fd;
 159         const char *file = sock_mem[which];
 160         ssize_t ret;
 161         char buff[64];
 162
 163         fd = open(file, O_WRONLY);
 164         if (fd < 0)
 165                 return;
 166
 167         memset(buff, 0, sizeof(buff));
 168         slprintf(buff, sizeof(buff), "%d", val);
 169
 170         ret = write(fd, buff, strlen(buff));
 171         if (ret < 0)
 172                 panic("Cannot set system socket memory!\n");
 173
 174         close(fd);
 175 }
 176
 177 void set_system_socket_memory(int *vals, size_t len)
 178 {
 179         bug_on(len != 4);
 180
 181         if ((vals[0] = get_system_socket_mem(sock_rmem_max)) < SMEM_SUG_MAX)
 182                 set_system_socket_mem(sock_rmem_max, SMEM_SUG_MAX);
 183         if ((vals[1] = get_system_socket_mem(sock_rmem_def)) < SMEM_SUG_DEF)
 184                 set_system_socket_mem(sock_rmem_def, SMEM_SUG_DEF);
 185         if ((vals[2] = get_system_socket_mem(sock_wmem_max)) < SMEM_SUG_MAX)
 186                 set_system_socket_mem(sock_wmem_max, SMEM_SUG_MAX);
 187         if ((vals[3] = get_system_socket_mem(sock_wmem_def)) < SMEM_SUG_DEF)
 188                 set_system_socket_mem(sock_wmem_def, SMEM_SUG_DEF);
 189 }
 190
 191 void reset_system_socket_memory(int *vals, size_t len)
 192 {
 193         bug_on(len != 4);
 194
 195         set_system_socket_mem(sock_rmem_max, vals[0]);
 196         set_system_socket_mem(sock_rmem_def, vals[1]);
 197         set_system_socket_mem(sock_wmem_max, vals[2]);
 198         set_system_socket_mem(sock_wmem_def, vals[3]);
 199 }