Re: [libvirt] [PATCH v7 10/19] utils: Implement function to pass a buffer to send via a fd to virCommand

Implement virCommandSetSendBuffer() that allows the caller to pass a file descriptor and buffer to virCommand. virCommand will write the buffer into the file descriptor. That file descriptor could be the write end of a pipe or one of the file descriptors of a socketpair. The other file descriptor should be passed to the launched process to read the data from. Only implement the function to allocate memory for send buffers and to free them later on. Signed-off-by: Stefan Berger <stefanb(a)linux.ibm.com&gt; Reviewed-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/libvirt_private.syms | 1 + src/util/vircommand.c | 93 ++++++++++++++++++++++++++++++++++++++++ src/util/vircommand.h | 5 +++ 3 files changed, 99 insertions(+)

+/** + * virCommandSetSendBuffer + * @cmd: the command to modify + * + * Pass a buffer to virCommand that will be written into the + * given file descriptor. The buffer will be freed automatically + * and the file descriptor closed. + */ +#if defined(F_SETFL) +int +virCommandSetSendBuffer(virCommandPtr cmd, + int fd, + unsigned char *buffer, size_t buflen) +{ + size_t i = virCommandGetNumSendBuffers(cmd);

+ + if (!cmd || cmd->has_error) + return -1; + + if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) { + virReportSystemError(errno, "%s", + _("fcntl failed to set O_NONBLOCK")); + cmd->has_error = errno; + return -1; + } + + if (VIR_REALLOC_N(cmd->sendBuffers, i + 1) < 0) { + cmd->has_error = ENOMEM; + return -1; + } + + cmd->sendBuffers[i].fd = fd; + cmd->sendBuffers[i].buffer = buffer; + cmd->sendBuffers[i].buflen = buflen; + cmd->sendBuffers[i].offset = 0; + + cmd->numSendBuffers++; + + return 0; +} + +#else /* !defined(F_SETFL) */ + +int +virCommandSetSendBuffer(virCommandPtr cmd, + int fd, + unsigned char *buffer, size_t buflen) +{ + if (!cmd || cmd->has_error) + return -1; + + cmd->has_error = ENOTSUP; + + return -1; +} + +#endif + /** * virCommandSetInputBuffer: * @cmd: the command to modify @@ -2867,6 +2958,8 @@ virCommandFree(virCommandPtr cmd) VIR_FREE(cmd->appArmorProfile); #endif + virCommandFreeSendBuffers(cmd); + VIR_FREE(cmd); } diff --git a/src/util/vircommand.h b/src/util/vircommand.h index 2a9ee5cdc7..c2abc7b2c3 100644 --- a/src/util/vircommand.h +++ b/src/util/vircommand.h @@ -146,6 +146,11 @@ void virCommandAddArgList(virCommandPtr cmd, void virCommandSetWorkingDirectory(virCommandPtr cmd, const char *pwd) ATTRIBUTE_NONNULL(2); +int virCommandSetSendBuffer(virCommandPtr cmd, + int fd, + unsigned char *buffer, size_t buflen) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3);

+ void virCommandSetInputBuffer(virCommandPtr cmd, const char *inbuf) ATTRIBUTE_NONNULL(2);