| 1 | #define _GNU_SOURCE |
| 2 | #include <sys/types.h> |
| 3 | #include <signal.h> |
| 4 | #include <errno.h> |
| 5 | #include <sys/socket.h> |
| 6 | #include <sys/un.h> |
| 7 | #include <unistd.h> |
| 8 | |
| 9 | #include <stdio.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <string.h> |
| 12 | |
| 13 | #include "ustcomm.h" |
| 14 | #include "localerr.h" |
| 15 | |
| 16 | #define UNIX_PATH_MAX 108 |
| 17 | #define SOCK_DIR "/tmp/socks" |
| 18 | #define UST_SIGNAL SIGIO |
| 19 | |
| 20 | #define MSG_MAX 1000 |
| 21 | |
| 22 | static void signal_process(pid_t pid) |
| 23 | { |
| 24 | int result; |
| 25 | |
| 26 | result = kill(pid, UST_SIGNAL); |
| 27 | if(result == -1) { |
| 28 | perror("kill"); |
| 29 | return; |
| 30 | } |
| 31 | |
| 32 | sleep(1); |
| 33 | } |
| 34 | |
| 35 | /* pid: the pid of the trace process that must receive the msg |
| 36 | msg: pointer to a null-terminated message to send |
| 37 | reply: location where to put the null-terminated string of the reply; |
| 38 | it must be free'd after usage |
| 39 | */ |
| 40 | |
| 41 | int send_message(pid_t pid, const char *msg, char **reply) |
| 42 | { |
| 43 | int fd; |
| 44 | int result; |
| 45 | struct sockaddr_un addr; |
| 46 | |
| 47 | result = fd = socket(PF_UNIX, SOCK_DGRAM, 0); |
| 48 | if(result == -1) { |
| 49 | perror("socket"); |
| 50 | return -1; |
| 51 | } |
| 52 | |
| 53 | addr.sun_family = AF_UNIX; |
| 54 | |
| 55 | result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid); |
| 56 | if(result >= UNIX_PATH_MAX) { |
| 57 | fprintf(stderr, "string overflow allocating socket name"); |
| 58 | return -1; |
| 59 | } |
| 60 | |
| 61 | signal_process(pid); |
| 62 | |
| 63 | result = sendto(fd, msg, strlen(msg), 0, (struct sockaddr *)&addr, sizeof(addr)); |
| 64 | if(result == -1) { |
| 65 | perror("sendto"); |
| 66 | return -1; |
| 67 | } |
| 68 | |
| 69 | if(!reply) |
| 70 | return 0; |
| 71 | |
| 72 | *reply = (char *) malloc(MSG_MAX+1); |
| 73 | result = recvfrom(fd, *reply, MSG_MAX, 0, NULL, NULL); |
| 74 | if(result == -1) { |
| 75 | perror("recvfrom"); |
| 76 | return -1; |
| 77 | } |
| 78 | |
| 79 | (*reply)[result] = '\0'; |
| 80 | |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg) |
| 85 | { |
| 86 | int fd; |
| 87 | int result; |
| 88 | struct sockaddr_un addr; |
| 89 | |
| 90 | *msg = (char *) malloc(MSG_MAX+1); |
| 91 | result = recvfrom(app->fd, *msg, MSG_MAX, 0, NULL, NULL); |
| 92 | if(result == -1) { |
| 93 | PERROR("recvfrom"); |
| 94 | return -1; |
| 95 | } |
| 96 | |
| 97 | DBG("ustcomm_app_recv_message: result is %d, message[1] is %hhd", result, (*msg)[1]); |
| 98 | (*msg)[result] = '\0'; |
| 99 | |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | static int init_named_socket(char *name, char **path_out) |
| 104 | { |
| 105 | int result; |
| 106 | int fd; |
| 107 | |
| 108 | struct sockaddr_un addr; |
| 109 | |
| 110 | result = fd = socket(PF_UNIX, SOCK_DGRAM, 0); |
| 111 | if(result == -1) { |
| 112 | PERROR("socket"); |
| 113 | return -1; |
| 114 | } |
| 115 | |
| 116 | addr.sun_family = AF_UNIX; |
| 117 | |
| 118 | strncpy(addr.sun_path, name, UNIX_PATH_MAX); |
| 119 | addr.sun_path[UNIX_PATH_MAX-1] = '\0'; |
| 120 | |
| 121 | result = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); |
| 122 | if(result == -1) { |
| 123 | PERROR("bind"); |
| 124 | goto close_sock; |
| 125 | } |
| 126 | |
| 127 | if(path_out) |
| 128 | *path_out = strdupa(addr.sun_path); |
| 129 | |
| 130 | return fd; |
| 131 | |
| 132 | close_sock: |
| 133 | close(fd); |
| 134 | |
| 135 | return -1; |
| 136 | } |
| 137 | |
| 138 | int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle) |
| 139 | { |
| 140 | int result; |
| 141 | char *name; |
| 142 | |
| 143 | result = asprintf(&name, "%s/%d", SOCK_DIR, (int)pid); |
| 144 | if(result >= UNIX_PATH_MAX) { |
| 145 | ERR("string overflow allocating socket name"); |
| 146 | return -1; |
| 147 | } |
| 148 | |
| 149 | handle->fd = init_named_socket(name, &handle->socketpath); |
| 150 | if(handle->fd < 0) { |
| 151 | goto free_name; |
| 152 | } |
| 153 | free(name); |
| 154 | |
| 155 | return 0; |
| 156 | |
| 157 | free_name: |
| 158 | free(name); |
| 159 | return -1; |
| 160 | } |
| 161 | |
| 162 | int ustcomm_init_ustd(struct ustcomm_ustd *handle) |
| 163 | { |
| 164 | handle->fd = init_named_socket("ustd", &handle->socketpath); |
| 165 | if(handle->fd < 0) |
| 166 | return handle->fd; |
| 167 | |
| 168 | return 0; |
| 169 | } |