C ssh2 执行命令

/*
 * The code sends a 'cat' command, and then writes a lot of data to it only to
 * check that reading the returned data sums up to the same amount.
 *
 * $ ./ssh2_echo 127.0.0.1 user password
 *
 */

#include 

#ifdef HAVE_SYS_SOCKET_H
#include 
#endif
#ifdef HAVE_UNISTD_H
#include 
#endif
#ifdef HAVE_NETINET_IN_H
#include 
#endif
#ifdef HAVE_ARPA_INET_H
#include 
#endif

#include 
#include 
#include 

static const char *hostname = "127.0.0.1";
static const char *commandline = "ifconfig";
static const char *username = "user";
static const char *password = "password";

static int waitsocket(libssh2_socket_t socket_fd, LIBSSH2_SESSION *session)
{
    struct timeval timeout;
    int rc;
    fd_set fd;
    fd_set *writefd = NULL;
    fd_set *readfd = NULL;
    int dir;

    timeout.tv_sec = 10;
    timeout.tv_usec = 0;

    FD_ZERO(&fd);

    FD_SET(socket_fd, &fd);

    /* now make sure we wait in the correct direction */
    dir = libssh2_session_block_directions(session);

    if(dir & LIBSSH2_SESSION_BLOCK_INBOUND)
        readfd = &fd;

    if(dir & LIBSSH2_SESSION_BLOCK_OUTBOUND)
        writefd = &fd;

    rc = select((int)(socket_fd + 1), readfd, writefd, NULL, &timeout);

    return rc;
}

#define BUFSIZE 32000

int cmd(int argc, char *argv[])
{
    uint32_t hostaddr;
    libssh2_socket_t sock;
    struct sockaddr_in sin;
    const char *fingerprint;
    int rc;
    LIBSSH2_SESSION *session = NULL;
    LIBSSH2_CHANNEL *channel;
    int exitcode = 0;
    char *exitsignal = (char *)"none";
    size_t len;
    LIBSSH2_KNOWNHOSTS *nh;
    int type;

#ifdef WIN32
    WSADATA wsadata;

    rc = WSAStartup(MAKEWORD(2, 0), &wsadata);
    if(rc) {
        fprintf(stderr, "WSAStartup failed with error: %d\n", rc);
        return 1;
    }
#endif

    if(argc > 1) {
        hostname = argv[1];  /* must be ip address only */
    }
    if(argc > 2) {
        username = argv[2];
    }
    if(argc > 3) {
        password = argv[3];
    }

    rc = libssh2_init(0);
    if(rc) {
        fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
        return 1;
    }

    hostaddr = inet_addr(hostname);

    /* Ultra basic "connect to port 22 on localhost".  Your code is
     * responsible for creating the socket establishing the connection
     */
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if(sock == LIBSSH2_INVALID_SOCKET) {
        fprintf(stderr, "failed to create socket!\n");
        goto shutdown;
    }

    sin.sin_family = AF_INET;
    sin.sin_port = htons(22);
    sin.sin_addr.s_addr = hostaddr;
    if(connect(sock, (struct sockaddr*)(&sin), sizeof(struct sockaddr_in))) {
        fprintf(stderr, "failed to connect!\n");
        goto shutdown;
    }

    /* Create a session instance */
    session = libssh2_session_init();
    if(!session) {
        fprintf(stderr, "Could not initialize SSH session!\n");
        goto shutdown;
    }

    /* tell libssh2 we want it all done non-blocking */
    libssh2_session_set_blocking(session, 0);

    /* ... start it up. This will trade welcome banners, exchange keys,
     * and setup crypto, compression, and MAC layers
     */
    while((rc = libssh2_session_handshake(session, sock)) ==
          LIBSSH2_ERROR_EAGAIN);
    if(rc) {
        fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
        goto shutdown;
    }

    nh = libssh2_knownhost_init(session);
    if(!nh) {
        /* eeek, do cleanup here */
        return 2;
    }

    /* read all hosts from here */
    libssh2_knownhost_readfile(nh, "known_hosts",
                               LIBSSH2_KNOWNHOST_FILE_OPENSSH);

    /* store all known hosts to here */
    libssh2_knownhost_writefile(nh, "dumpfile",
                                LIBSSH2_KNOWNHOST_FILE_OPENSSH);

    fingerprint = libssh2_session_hostkey(session, &len, &type);
    if(fingerprint) {
        struct libssh2_knownhost *host;
        int check = libssh2_knownhost_checkp(nh, hostname, 22,
                                             fingerprint, len,
                                             LIBSSH2_KNOWNHOST_TYPE_PLAIN|
                                             LIBSSH2_KNOWNHOST_KEYENC_RAW,
                                             &host);

        fprintf(stderr, "Host check: %d, key: %s\n", check,
                (check <= LIBSSH2_KNOWNHOST_CHECK_MISMATCH) ?
                host->key : "");

        /*****
         * At this point, we could verify that 'check' tells us the key is
         * fine or bail out.
         *****/
    }
    else {
        /* eeek, do cleanup here */
        return 3;
    }
    libssh2_knownhost_free(nh);

    if(strlen(password) != 0) {
        /* We could authenticate via password */
        while((rc = libssh2_userauth_password(session, username, password)) ==
              LIBSSH2_ERROR_EAGAIN);
        if(rc) {
            fprintf(stderr, "Authentication by password failed!\n");
            exit(1);
        }
    }

    libssh2_trace(session, LIBSSH2_TRACE_SOCKET);

    /* Exec non-blocking on the remote host */
    do {
        channel = libssh2_channel_open_session(session);
        if(channel ||
           libssh2_session_last_error(session, NULL, NULL, 0) !=
           LIBSSH2_ERROR_EAGAIN)
            break;
        waitsocket(sock, session);
    } while(1);
    if(!channel) {
        fprintf(stderr, "Error\n");
        exit(1);
    }
    while((rc = libssh2_channel_exec(channel, commandline)) ==
          LIBSSH2_ERROR_EAGAIN) {
        waitsocket(sock, session);
    }
    if(rc) {
        fprintf(stderr, "exec error\n");
        exit(1);
    }
    else {
        LIBSSH2_POLLFD *fds = NULL;
        int running = 1;
        ssize_t bufsize = BUFSIZE;
        char buffer[BUFSIZE];
        ssize_t totsize = 1500000;
        ssize_t totwritten = 0;
        ssize_t totread = 0;
        int rereads = 0;
        int rewrites = 0;
        int i;
        fds = (LIBSSH2_POLLFD*)malloc(sizeof(LIBSSH2_POLLFD));
        if(!fds) {
            fprintf(stderr, "malloc failed\n");
            exit(1);
        }

        fds[0].type = LIBSSH2_POLLFD_CHANNEL;
        fds[0].fd.channel = channel;
        fds[0].events = LIBSSH2_POLLFD_POLLIN | LIBSSH2_POLLFD_POLLOUT;

        do {
            int act = 0;
            rc = libssh2_poll(fds, 1, 10);
            if(rc < 1)
                continue;
            if(fds[0].revents & LIBSSH2_POLLFD_POLLIN) {
                ssize_t n = libssh2_channel_read(channel,
                                                 buffer, sizeof(buffer));
                act++;
                printf("%s\n",buffer);
                if(n == LIBSSH2_ERROR_EAGAIN) {
                    rereads++;
                    fprintf(stderr, "will read again\n");
                }
                else if(n < 0) {
                    fprintf(stderr, "read failed\n");
                    exit(1);
                }
                else {
                    totread += n;
                    fprintf(stderr, "read %d bytes (%d in total)\n",
                            (int)n, (int)totread);
                }
            }
            if(fds[0].revents & LIBSSH2_POLLFD_CHANNEL_CLOSED) {
                if(!act) /* don't leave loop until we have read all data */
                    running = 0;
            }
        } while(running);
        exitcode = 127;
        while((rc = libssh2_channel_close(channel)) == LIBSSH2_ERROR_EAGAIN)
            waitsocket(sock, session);

        if(rc == 0) {
            exitcode = libssh2_channel_get_exit_status(channel);
            libssh2_channel_get_exit_signal(channel, &exitsignal,
                                            NULL, NULL, NULL, NULL, NULL);
        }

        if(exitsignal)
            fprintf(stderr, "\nGot signal: %s\n", exitsignal);

        libssh2_channel_free(channel);
        channel = NULL;
    }

shutdown:

    if(session) {
        libssh2_session_disconnect(session, "Normal Shutdown");
        libssh2_session_free(session);
    }

    if(sock != LIBSSH2_INVALID_SOCKET) {
        shutdown(sock, 2);
#ifdef WIN32
        closesocket(sock);
#else
        close(sock);
#endif
    }

    fprintf(stderr, "all done\n");

    libssh2_exit();

    return exitcode;
}
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示例代码修改

示例代码调整

/*
 * The code sends a 'cat' command, and then writes a lot of data to it only to
 * check that reading the returned data sums up to the same amount.
 *
 * $ ./ssh2_echo 127.0.0.1 user password
 *
 */

#include 

#ifdef HAVE_SYS_SOCKET_H
#include 
#endif
#ifdef HAVE_UNISTD_H
#include 
#endif
#ifdef HAVE_NETINET_IN_H
#include 
#endif
#ifdef HAVE_ARPA_INET_H
#include 
#endif
#include 
#include 
#include 
#include 
#include "ssh2_exec.h"
const char *hostname = "192.168.1.110";
const char *password = "root";
const char *username = "root";
static libssh2_socket_t sock;
LIBSSH2_SESSION *session = NULL;
LIBSSH2_CHANNEL *channel;

static int waitsocket(libssh2_socket_t socket_fd, LIBSSH2_SESSION *_session) {
  struct timeval timeout;
  int rc;
  fd_set fd;
  fd_set *writefd = NULL;
  fd_set *readfd = NULL;
  int dir;

  timeout.tv_sec = 10;
  timeout.tv_usec = 0;

  FD_ZERO(&fd);

  FD_SET(socket_fd, &fd);

  /* now make sure we wait in the correct direction */
  dir = libssh2_session_block_directions(_session);

  if (dir & LIBSSH2_SESSION_BLOCK_INBOUND)
    readfd = &fd;

  if (dir & LIBSSH2_SESSION_BLOCK_OUTBOUND)
    writefd = &fd;

  rc = select((int)(socket_fd + 1), readfd, writefd, NULL, &timeout);

  return rc;
}

#define BUFSIZE 32000

int setupSSH2(void) {
  uint32_t hostaddr;
  struct sockaddr_in sin;
  const char *fingerprint;
  int rc;
  size_t len;
  LIBSSH2_KNOWNHOSTS *nh;
  int type;
#ifdef WIN32
  WSADATA wsadata;
  rc = WSAStartup(MAKEWORD(2, 0), &wsadata);
  if (rc) {
    fprintf(stderr, "WSAStartup failed with error: %d\n", rc);
    return 1;
  }
#endif
  rc = libssh2_init(0);
  if (rc) {
    fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
    return 1;
  }
  hostaddr = inet_addr(hostname);
  /* Ultra basic "connect to port 22 on localhost".  Your code is
   * responsible for creating the socket establishing the connection
   */
  sock = socket(AF_INET, SOCK_STREAM, 0);
  if (sock == LIBSSH2_INVALID_SOCKET) {
    fprintf(stderr, "failed to create socket!\n");
    return 1;
  }
  sin.sin_family = AF_INET;
  sin.sin_port = htons(22);
  sin.sin_addr.s_addr = hostaddr;
  if (connect(sock, (struct sockaddr *)(&sin), sizeof(struct sockaddr_in))) {
    fprintf(stderr, "failed to connect!\n");
    return 1;
  }
  /* Create a session instance */
  session = libssh2_session_init();
  if (!session) {
    fprintf(stderr, "Could not initialize SSH session!\n");
    return 1;
  }

  /* tell libssh2 we want it all done non-blocking */
  libssh2_session_set_blocking(session, 0);

  /* ... start it up. This will trade welcome banners, exchange keys,
   * and setup crypto, compression, and MAC layers
   */
  while ((rc = libssh2_session_handshake(session, sock)) ==
         LIBSSH2_ERROR_EAGAIN)
    ;
  if (rc) {
    fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
    return 1;
  }

  nh = libssh2_knownhost_init(session);
  if (!nh) {
    /* eeek, do cleanup here */
    return 2;
  }

  /* read all hosts from here */
  libssh2_knownhost_readfile(nh, "known_hosts", LIBSSH2_KNOWNHOST_FILE_OPENSSH);

  /* store all known hosts to here */
  libssh2_knownhost_writefile(nh, "dumpfile", LIBSSH2_KNOWNHOST_FILE_OPENSSH);

  fingerprint = libssh2_session_hostkey(session, &len, &type);
  if (fingerprint) {
    struct libssh2_knownhost *host;
    libssh2_knownhost_checkp(
        nh, hostname, 22, fingerprint, len,
        LIBSSH2_KNOWNHOST_TYPE_PLAIN | LIBSSH2_KNOWNHOST_KEYENC_RAW, &host);
    /*****
     * At this point, we could verify that 'check' tells us the key is
     * fine or bail out.
     *****/
  } else {
    /* eeek, do cleanup here */
    return 3;
  }
  libssh2_knownhost_free(nh);

  if (strlen(password) != 0) {
    /* We could authenticate via password */
    while ((rc = libssh2_userauth_password(session, username, password)) ==
           LIBSSH2_ERROR_EAGAIN)
      ;
    if (rc) {
      fprintf(stderr, "Authentication by password failed!\n");
      exit(1);
    }
  }
  libssh2_trace(session, LIBSSH2_TRACE_SOCKET);
  /* Exec non-blocking on the remote host */
  return 0;
}

int32_t SSH2_CMD(const char *commandline, char *err, ssize_t e_len, char *out,
                 ssize_t o_len) {
  int32_t rc = 0;
  int32_t exitcode = 0;
  char buffer_cache[BUFSIZE];
  char *buffer = buffer_cache;
  ssize_t n = 0;
  do {
    channel = libssh2_channel_open_session(session);
    if (channel || libssh2_session_last_error(session, NULL, NULL, 0) !=
                       LIBSSH2_ERROR_EAGAIN)
      break;
    waitsocket(sock, session);
  } while (1);
  if (!channel) {
    fprintf(stderr, "Error\n");
    exit(1);
  }
  while ((rc = libssh2_channel_exec(channel, commandline)) ==
         LIBSSH2_ERROR_EAGAIN) {
    waitsocket(sock, session);
  }
  if (rc) {
    fprintf(stderr, "exec error\n");
    return 1;
  }
  while ((rc = libssh2_channel_send_eof(channel)) == LIBSSH2_ERROR_EAGAIN) {
    waitsocket(sock, session);
  }
  if (rc) {
    fprintf(stderr, "exec error\n");
    return 1;
  } else {
    memset(buffer, 0, BUFSIZ);
    do {
      n = libssh2_channel_read(channel, buffer, BUFSIZE);
      if (n < 0 && n != LIBSSH2_ERROR_EAGAIN) {
        fprintf(stderr, "read failed\n");
        break;
      }
    } while (n == LIBSSH2_ERROR_EAGAIN);
    memcpy(out ,buffer, n > o_len ? o_len : n);
    memset(buffer, 0, BUFSIZ);
    do {
      n = libssh2_channel_read_stderr(channel, buffer, BUFSIZE);
      if (n < 0 && n != LIBSSH2_ERROR_EAGAIN) {
        fprintf(stderr, "read failed\n");
        break;
      }
    } while (n == LIBSSH2_ERROR_EAGAIN);
    memcpy(err, buffer, n > e_len ? e_len : n);
    while ((rc = libssh2_channel_close(channel)) == LIBSSH2_ERROR_EAGAIN)
      waitsocket(sock, session);
  }
  return 0;
}

int32_t SSH2_CLOSE(void) {
  if (sock != LIBSSH2_INVALID_SOCKET) {
    shutdown(sock, 2);
#ifdef WIN32
    closesocket(sock);
#else
    close(sock);
#endif
  }
  libssh2_channel_free(channel);
  channel = NULL;
  if (session) {
    libssh2_session_disconnect(session, "Normal Shutdown");
    libssh2_session_free(session);
  }
  libssh2_exit();
  return 0;
}
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